java线程概念案例说明
来源:互联网 发布:淘宝上厂名厂址怎么写 编辑:程序博客网 时间:2024/05/17 05:51
java线程一直是一个比较容易困扰的地方,很多初学者都不是很清楚,
在此,我用了几个小试验,来将其基本概念说明一下,首先把run(),start()区分开来,
看看为什么直接调用run()和用start()启动一个线程的差别
1.
package com.dragon;
import java.lang.Thread;
public class ThreadTest extends Thread {
public void run() {
for(int i=0;i<10;i++){
System.out.println("this is a Thread test");
}
}
public static void main(String[] args) {
try {
Thread t = new ThreadTest();
t.run();
System.out.println("main thread is over");
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
输出结果:
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
main thread is over
表明,run()和其他方法的调用没任何不同,main方法按顺序执行了它,并打印出最后一句,
退出程序.下面看看把调用改为start()
2.
package com.dragon;
import java.lang.Thread;
public class ThreadTest extends Thread {
public void run() {
for(int i=0;i<10;i++){
System.out.println("this is a Thread test");
}
}
public static void main(String[] args) {
try {
Thread t = new ThreadTest();
t.start();
System.out.println("main thread is over");
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
输出结果:
main thread is over
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
这表明,start()方法重新创建了一个线程,在main方法执行结束后,由于start()方法创建的
线程没有运行结束,因此主线程未能退出,直到线程 t 也执行完毕,这里要注意,默认创建的
线程是用户线程(非守护线程),再改一下代码
3.
package com.dragon;
import java.lang.Thread;
public class ThreadTest extends Thread {
public void run() {
for(int i=0;i<10;i++){
System.out.println("this is a Thread test");
}
}
public static void main(String[] args) {
try {
Thread t = new ThreadTest();
t.setDaemon(true);
t.start();
System.out.println("main thread is over");
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
输出为:
main thread is over
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
为什么没有打印出十句呢,因为我们将 t 线程设置为了daemon(守护)线程,
程序中只有守护线程存在的时候,是可以退出的,所以只打印了七句便退出了.
再改一下代码
4.
package com.dragon;
import java.lang.Thread;
public class ThreadTest extends Thread {
public void run() {
for(int i=0;i<100;i++){
System.out.println("this is a Thread test");
}
}
public static void main(String[] args) {
try {
Thread t = new ThreadTest();
t.start();
System.out.println("main thread is over");
System.exit(0);
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
main thread is over
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
this is a Thread test
结果可见,用户线程可以被System.exit(0)强制kill掉,所以也只打印出七句.
- java线程概念案例说明
- java线程概念案例说明
- java线程概念案例
- java线程概念案例
- java反射概念加案例
- java 基本线程概念
- Java线程的概念
- JAVA线程概念
- Java线程的概念
- java 线程_sql概念
- java线程基础概念
- JAVA线程概念
- Java线程的概念
- Java线程的概念
- java 线程相关概念
- java线程概念区别
- java--线程--概念
- java集合List案例说明
- 文章测试
- 一个图形验证码页面(Asp.Net2.0通过)
- 泛型小记
- MVC模式
- EasyJF开源从网上走到网下
- java线程概念案例说明
- 大家好,欢迎来到我的网站!
- 简易C# IDE 操作系统:Windows 类库平台: =>.net 2.0 作者:人之王晓东
- SSH...
- 1. 服务(Service)开发的纪律
- 2. 设备I/O及线程间通讯
- 3. 服务应用程序
- 4. 服务控制程序
- 5. 系统登录