0013 java运行内存分配图【原理】

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Java的内存分配  Java程序运行时的内存结构分成:方法区、栈内存、堆内存、本地方法栈几种。  方法区   存放装载的类数据信息,包括:基本信息:每个类的全限定名、每个类的直接超类的全限定名、该类是类还是接口、该类型的访问修饰符、直接超接口的全限定名的有序列表。每个已装载类的详细信息:运行时常量池、字段信息、方法信息、静态变量、到类classloader的引用、到类class的引用。  栈内存    Java栈内存由局部变量区、操作数栈、帧数据区组成,以帧的形式存放本地方法的调用状态(包括方法调用的参数、局部变量、中间结果……)。  堆内存    堆内存用来存放由new创建的对象和数组。在堆中分配的内存,由Java虚拟机的自动垃圾回收器来管理。  本地方法栈内存    Java通过Java本地接口JNI(Java Native Interface)来调用其它语言编写的程序,在Java里面用native修饰符来描述一个方法是本地方法 Java对象创建内存示意图
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</pre><pre id="content-774350520" class="reply-text mb10" name="code"><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">java中内存主要包含4块,即heap(堆内存)、stack(栈内存)、data segment(静态变量或是常量存放区)、codesegment(方法区). </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">堆内存中存放的是new出的对象,new出的对象只包含成员变量。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">栈内存中:存放的是局部成员变量。对于基本的数据类型存放的是基本变量的值,而对于对象变量,存放的是堆内存的地址。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">静态、常量区:存放的是静态变量(类变量)或是常量。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">方法区:存放的是对象的方法。因此即使new出多个对象也是只是存在一个方法。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">如 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">A a = new A(); A中含有一个work方法,2个成员变量a,b。那么对应的内存分配为 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">则 a是分配在栈内存中。里面存放了一个指向堆内存中存放的new A()的地址。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">new A()会导致在堆内存中分配一块空间,该内存中的A对象同时会含有a和b。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">work()方法会在codesegment区中分配内存。 </span><br style="FONT-SIZE: 14px; FONT-FAMILY: Helvetica,Tahoma,Arial,sans-serif; TEXT-ALIGN: left; LINE-HEIGHT: 25px" /><span style="font-family:Helvetica,Tahoma,Arial,sans-serif;font-size:14px;TEXT-ALIGN: left; LINE-HEIGHT: 25px">如果此时 A b = a;则表示把a的值复制给b,即b的值为a中保存的地址</span>
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<span style="font-family:Helvetica,Tahoma,Arial,sans-serif;"><span style="font-size:14px;LINE-HEIGHT: 25px"></span></span><p style="FONT-SIZE: 13px; FONT-FAMILY: Arial, Helvetica, sans-serif; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 19px; BACKGROUND-COLOR: rgb(254,254,242)">这是一篇关于Java内存结构组织的文章,涉及的概念主要有<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">方法区</span>、<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">Java栈</span>、<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">java堆</span>。通过这个文章,可以加深对Java对象的理解,以及优化代码的结构。<br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></p><p style="FONT-SIZE: 13px; FONT-FAMILY: Arial, Helvetica, sans-serif; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 19px; BACKGROUND-COLOR: rgb(254,254,242)"> </p><p style="FONT-SIZE: 13px; FONT-FAMILY: Arial, Helvetica, sans-serif; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 19px; BACKGROUND-COLOR: rgb(254,254,242)">开始: <br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></p><p style="FONT-SIZE: 13px; FONT-FAMILY: Arial, Helvetica, sans-serif; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 19px; BACKGROUND-COLOR: rgb(254,254,242)"></p><div style="FONT-SIZE: 13px; FONT-FAMILY: Arial, Helvetica, sans-serif; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 19px; PADDING-RIGHT: 0px; BACKGROUND-COLOR: rgb(254,254,242)"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"></span><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" align="center" border="2"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em; TEXT-INDENT: 21pt"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">想写这篇总结酝酿了有个来月了,却始终感觉还差点什么东西,一直未敢动笔。</span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">       </span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">最近两天连夜奋战,</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">重新整理下</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">前面查阅的资料、笔记,还是决定将它写出来。</span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">       </span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">现在提出几个问题,<span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">如果都能熟练回答的大虾,请您飘过.</span></span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">如以往一样,我是小菜,本文自然也是针对小菜阶层的总结。</span></p></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">首先是概念层面的几个问题:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><ul style="WORD-BREAK: break-all; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 0px 45px; PADDING-RIGHT: 0px"><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java中运行时内存结构有哪几种?</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java中为什么要设计堆栈分离?</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java多线程中是如何实现数据共享的?</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java反射的基础是什么?</span></li></ul><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">然后是运用层面:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><ul style="WORD-BREAK: break-all; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 0px 45px; PADDING-RIGHT: 0px"><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">引用类型变量和对象的区别?</span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">什么情况下用局部变量,什么情况下用成员变量?</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">数组如何初始化?声明一个数组的过程中,如何分配内存?</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">声明基本类型数组和声明引用类型的数组,初始化时,内存分配机制有什么区?</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在什么情况下,我们的方法设计为静态化,为什么?(上次胡老师问文奇,问的哑口无言,当时想回答,却老感觉表述不清楚,这里也简单说明一下)</span></li></ul><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">好了,问题提完了,<span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">如果您都能一眼看出答案,那么,没有必要再浪费您宝贵的时间看下去了</span></span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">。</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">如果您还不太明白,请跟随我一路走下去。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java中运行时内存结构</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">   </span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">1.1 方法区:</span> </span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 12pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">方法区是系统分配的一个内存逻辑区域,是<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">JVM</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在装载类文件时,用于存储类型信息的</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">类的描述信息</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">)。</span></span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    </span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">方法区存放的信息包括:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">            </span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">1.1.1<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">类的基本信息:</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><ol style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 0px 2em; PADDING-RIGHT: 0px"><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">每个类的全限定名</span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">每个类的直接超类的全限定名</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">可约束类型转换</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">)</span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">该类是类还是接口</span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">该类型的访问修饰符</span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">直接超接口的全限定名的有序列表</span></li></ol><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">             1.1.2<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">已装载类的详细信息</span>:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><ol style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 0px 2em; PADDING-RIGHT: 0px"><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> <span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">运行时常量池</span>:</span></span><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 96pt; LINE-HEIGHT: 1.5em" align="left"><span style="FONT-SIZE: 12pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在方法区中,每个类型都对应一个常量池,存放该类型所用到的所有常量,常量池中存储了诸如</span></span><span style="FONT-SIZE: 12pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">文字字符串、</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">final</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">变量值、类名和方法名常量。</span></span><span style="FONT-SIZE: 12pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">它们以数组形式通过索引被访问,是外部调用与类联系及类型对象化的桥梁。(存的可能是个普通的字符串,然后经过常量池解析,则变成指向某个类的引用)</span></span></p></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> <span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">字段信息</span>:</span></span><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 96pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">字段信息存放类中声明的每一个字段的信息,包括字段的名、类型、修饰符。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 96pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 12pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">字段名称指的是类或接口的实例变量或类变量,字段的描述符是一个指示字段的类型的字符串,如</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">private A a=null;</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">则</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">a</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">为字段名,</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">A</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">为描述符,</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">private</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">为修饰符</span></span></p></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> <span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">方法信息</span>:</span></span><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 96pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">类中声明的每一个方法的信息,包括方法名、返回值类型、参数类型、修饰符、异常、方法的字节码。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 96pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(在编译的时候,就已经将方法的局部变量、操作数栈大小等确定并存放在字节码中,在装载的时候,随着类一起装入方法区</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">。)</span></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px">在运行时,JVM从常量池中获得符号引用,然后在运行时解析成引用项的实际地址,最后通过常量池中的全限定名、方法和字段描述符,把当前类或接口中的代码与其它类或接口中的代码联系起来。</td></tr></tbody></table></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> <span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">静态变量</span>:</span></span><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 57pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">这个没什么好说的,就是类变量,类的所有实例都共享,我们只需知道,在方法区有个静态区,静态区专门存放静态变量和静态块。</span></p></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> </span><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">到类</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">classloader</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">的引用</span></span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">:</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">到该类的类装载器的引用。</span></span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em 57pt; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> </span><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">到类</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">class </span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">的引用</span></span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">:</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">虚拟机为每一个被装载的类型创建一个</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">class </span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">实例,用来代表这个被装载的类。</span></span> </li></ol><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">  </span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> 由此我们可以知道反射的基础</span></span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">:</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在装载类的时候,加入方法区中的所有信息,最后都会形成Class类的实例,代表这个被装载的类。方法区中的所有的信息,都是可以通过这个Class类对象反射得</span></span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">到。</span></span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">我们知道对象是类的实例,类是相同结构的对象的一种抽象。同类的各个对象之间,其实是拥有相同的结构(属性),拥有相同的功能(方法),</span><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">各个对象的区别只在于属性值的不同</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    同样的,我们所有的类,其实都是Class类的实例,他们都拥有相同的结构-----Field数组、Method数组。而各个类中的属性都是Field属性的一个具体属性值,方法都是Method属性的一个具体属性值。</span></span></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> <span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在运行时,JVM从常量池中获得符号引用,然后在运行时解析成引用项的实际地址,最后通过常量池中的全限定名、方法和字段描述符,把当前类或接口中的代码与其它类或接口中的代码联系起来。</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">1.2 </span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java栈</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">JVM</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">栈是程序运行时单位,决定了程序如何执行,或者说数据如何处理。</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">中,一个线程就会有一个线程的</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">JVM</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">栈与之对应,因为不过的线程执行逻辑显然不同,因此都需要一个独立的</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">JVM</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">栈来存放该线程的执行逻辑。</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">对方法的调用:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">栈内存,以</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">帧</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">的形式存放</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">本地方法</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">的</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">调用状态</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">,包括方法调用的</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">参数</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">、</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">局部变量、中间结果</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">等(方法都是以方法帧的形式存放在方法区的),每调用一个方法就将对应该方法的方法帧压入</span><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java </span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">栈,成为当前方法帧。当调用结束</span><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">返回</span><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">)</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">时,就弹出该帧。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> </span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">这意味着:</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在方法中定义的一些</span><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">基本类型</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">的变量和</span><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">引用变量</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">都在方法的栈内存中分配。</span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">当在一段代码块定义一个变量时,</span><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java </span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">就在栈中为这个变量分配内存空间,当超过变量的作用域后(方法执行完成后),</span><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java </span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">会自动释放掉为该变量所分配的内存空间,该内存空间可以立即被另作它用</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">。</span><span style="color:#dddddd;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">--------</span></span><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">同时,因为变量被释放,该变量对应的对象,也就失去了引用,也就变成了可以被gc对象回收的垃圾。</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">因此我们可以知道成员变量与局部变量的区别:</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">局部变量,在方法内部声明,当该方法运行完时,内存即被释放。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">成员变量,只要该对象还在,哪怕某一个方法运行完了,还是存在。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">从系统的角度来说,声明局部变量有利于内存空间的更高效利用(方法运行完即回收)。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">成员变量可用于各个方法间进行数据共享。</span></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java 栈内存的组成:</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">局部变量区、操作数栈、帧数据区组成。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(1): 局部变量区为一个以字为单位的数组,每个数组元素对应一个局部变量的值。调用方法时,将方法的局部变量组成一个数组,通过索引来访问。若为非静态方法,则 加入一个隐含的引用参数this,该参数指向调用这个方法的对象。而静态方法则没有this参数。因此,对象无法调用静态方法。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">由此,我们可以知道,方法什么时候设计为静态,什么时候为非静态?</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">前面已经说过,对象是类的一个实例,各个对象结构相同,只是属性不同。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">而静态方法是对象无法调用的。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">所以,静态方法适合那些工具类中的工具方法,这些类只是用来实现一些功能,也不需要产生对象,通过设置对象的属性来得到各个不同的个体。</span></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(2):操作数栈也是一个数组,但是通过栈操作来访问。所谓操作数是那些被指令操作的数据。当需要对参数操作时如a=b+c,就将即将被操作的参数压栈,如将b 和c 压栈,然后由操作指令将它们弹出,并执行操作。虚拟机将操作数栈作为工作区。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(3):帧数据区处理常量池解析,异常处理等</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto 5px 39pt; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">1.3 </span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">java堆 </span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">      java的堆是一个运行时的数据区,用来存储数据的单元,存放通过new关键字新建的</span><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">对象</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">和</span><span style="color:#0ccff;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">数组</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">,对象从中分配内存。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">      在堆中声明的对象,是不能直接访问的,必须通过在栈中声明的指向该引用的变量来调用。引用变量就相当于是为数组或对象起的一个名称,以后就可以在程序中使用栈中的引用变量来访问堆中的数组或对象。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">   </span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    </span><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"> 由此我们可以知道,引用类型变量和对象的区别: </span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">声明的对象是在堆内存中初始化的, 真正用来存储数据的。不能直接访问。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">引用类型变量是保存在栈当中的,一个用来引用堆中对象的符号而已(指针)。</span></p></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">堆与栈的比较</span></span>:</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">JAVA堆与栈都是用来存放数据的,那么他们之间到底有什么差异呢?既然栈也能存放数据,为什么还要设计堆呢?</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="color:#ffcc0;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">1.</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">从存放数据的角度:</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">      </span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">前面我们已经说明:</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">      栈中存放的是基本类型的变量</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">or</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">引用类型的变量</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">       </span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">堆中存放的是对象</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">or</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">数组对象.</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">       在栈中,引用变量的大小为32位,基本类型为1-8个字节。</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">       但是对象的大小和数组的大小是动态的,这也决定了堆中数据的动态性,因为它是在运行时动态分配内存的,</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">生存期也不必在编译时确定,</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Java 的垃圾收集器会自动收走这些不再使用的数据。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="COLOR: rgb(255,204,0); PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">2.</span></span><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">从数据共享的角度</span>:</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    1).在单个线程类,栈中的数据可共享</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    例如我们定义:</span></p><div style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><div style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><div style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">Java代码</div></div><ol style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 0px 2em; PADDING-RIGHT: 0px"><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">int a=3;  </span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">int b=3;  </span></li></ol></div><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    </span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">编 译器先处理int a = 3;首先它会在栈中创建一个变量为a 的引用,然后查找栈中是否有3 这个值,如果没找到,就将3 存放进来,然后将a 指向3。接着处理int b = 3;在创建完b 的引用变量后,因为在栈中已经有3这个值,便将b 直接指向3。这样,就出现了a 与b 同时均指向3的情况。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    而如果我们定义:</span> </p><div style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><div style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><div style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">Java代码</div></div><ol style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 0px 2em; PADDING-RIGHT: 0px"><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">Integer a=new Integer(3);//(1)  </span></li><li style="LIST-STYLE-TYPE: disc; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px 0px 1em; PADDING-RIGHT: 0px">Integer b=<span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">new Integer(3);//(2)  </span></li></ol></div><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">   </span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">这个时候执行过程为:在执行(1)时,首先在栈中创建一个变量a,然后在堆内存中实例化一个对象,并且将变量a指向这个实例化的对象。在执行(2)时,过程类似,此时,在堆内存中,会有两个Integer类型的对象。 </span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">    2).<span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px">在进程的各个线程之间,数据的共享通过堆来实现</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">        </span><span style="font-family:宋体;color:#dddddd;FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">例:那么,在多线程开发中,我们的数据共享又是怎么实现的呢?</span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span><img style="BORDER-LEFT-WIDTH: 0px; BORDER-RIGHT-WIDTH: 0px; BORDER-BOTTOM-WIDTH: 0px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px; BORDER-TOP-WIDTH: 0px" alt="" src="http://dl.javaeye.com/upload/attachment/371820/f2f9c166-ea8b-327f-bc12-c13ede0a6125.gif" /></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">  如图所示,堆中的数据是所有线程栈所共享的,我们可以通过参数传递,将一个堆中的数据传入各个栈的工作内存中,从而实现多个线程间的数据共享</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">(多个进程间的数据共享则需要通过网络传输了。) </span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 10.5pt; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="color:#ffcc0;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">3.从程序设计的的角度:</span></span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">从软件设计的角度看,JVM栈代表了处理逻辑,而JVM堆代表了数据。这样分开,使得处理逻辑更为清晰。分而治之的思想。这种隔离、模块化的思想在软件设计的方方面面都有体现。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="color:#ffcc0;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">4.值传递和引用传递的真相</span></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">有了以上关于栈和堆的种种了解后,我们很容易就可以知道值传递和引用传递的真相:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">1.程序运行永远都是在JVM栈中进行的,因而参数传递时,只存在传递基本类型和对象引用的问题。不会直接传对象本身。</span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">但是传引用的错觉是如何造成的呢?</span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">在运行JVM栈中,基本类型和引用的处理是一样的,都是传值,所以,如果是传引用的方法调用,也同时可以理解为“传引用值”的传值调用,即引用的处理跟基本类型是完全一样的。</span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">但是当进入被调用方法时,被传递的这个引用的值,被程序解释(或者查找)到JVM堆中的对象,这个时候才对应到真正的对象。</span></p><p style="FONT-SIZE: 13px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">如果此时进行修改,修改的是引用对应的对象,而不是引用本身,即:修改的是JVM堆中的数据。所以这个修改是可以保持的了。</span></p></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">最后:</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">从某种意义上来说</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">对象都</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">是由基本类型组成的。</span></span> </p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><table style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px auto; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 0px" border="1"><tbody style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><tr style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><td style="BORDER-TOP: rgb(192,192,192) 1px solid; BORDER-RIGHT: rgb(192,192,192) 1px solid; BORDER-COLLAPSE: collapse; BORDER-BOTTOM: rgb(192,192,192) 1px solid; PADDING-BOTTOM: 3px; PADDING-TOP: 3px; PADDING-LEFT: 3px; MARGIN: 0px; BORDER-LEFT: rgb(192,192,192) 1px solid; PADDING-RIGHT: 3px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">可以把一个对象看作为一棵树,对象的属性如果还是对象,则还是一颗树(即非叶子节点),基本类型则为树的叶子节点。程序参数传递时,被传递的值本身都是不能进行修改的,但是,如果这个值是一个非叶子节点(即一个对象引用),则可以修改这个节点下面的所有内容。 </span></td></tr></tbody></table><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><br style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px" /></span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; PADDING-RIGHT: 0px"><span style="color:#ff00;PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">其实,面向对象方式的程序与以前结构化的程序在执行上没有任何区别</span></span></span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">。</span></p><p style="PADDING-BOTTOM: 0px; PADDING-TOP: 0px; MARGIN: 5px auto; LINE-HEIGHT: 1.5em"><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">面向对象的引入,只是</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">改变了我们</span><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">对待问题的思考方式,而更接近于自然方式的思考。</span></p><span style="FONT-SIZE: 16px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px; PADDING-LEFT: 0px; MARGIN: 0px; LINE-HEIGHT: 1.5; PADDING-RIGHT: 0px">当我们把对象拆开,其实对象的属性就是数据,存放在JVM堆中;而对象的行为(方法),就是运行逻辑,放在JVM栈中。我们在编写对象的时候,其实即编写了数据结构,也编写的处理数据的逻辑。</span></div>
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