Linux JDK学习笔记

1.查询是否安装了jdk

[root@iZ94lys8uuzZ ~]# rpm -q jdk

jdk-1.7.0_67-fcs.x86_64

[root@iZ94lys8uuzZ ~]# rpm -qa|grep jdk

jdk-1.7.0_67-fcs.x86_64

[root@iZ94lys8uuzZ ~]# java -version

java version "1.7.0_67"

Java(TM) SE Runtime Environment (build 1.7.0_67-b01)

Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

 

2、卸载原版本的jdk

[root@iZ94lys8uuzZ ~]# rpm -qa|grep jdk

jdk-1.7.0_67-fcs.x86_64

[root@iZ94lys8uuzZ ~]# rpm -e --nodeps jdk-1.7.0_67-fcs.x86_64

 

卸载完成后：

[root@iZ94lys8uuzZ ~]# rpm -qa|grep jdk

[root@iZ94lys8uuzZ ~]# java -version

-bash: /usr/bin/java: No such file or directory

 

3、将jdk linux安装包上传到目录/usr/rmp

 

 

4、进入/usr/rmp并安装jdk

[root@iZ94lys8uuzZ ~]# cd /usr/rmp/

[root@iZ94lys8uuzZ rmp]# rpm -ivh jdk-7u67-linux-x64.rpm

Preparing...                ########################################### [100%]

   1:jdk                    ########################################### [100%]

Unpacking JAR files...

        rt.jar...

        jsse.jar...

        charsets.jar...

        tools.jar...

        localedata.jar...

        jfxrt.jar...

[root@iZ94lys8uuzZ rmp]#

 

 

安装完成后：

 

5、设置环境变量

修改文件：/etc/profile

在最后边加上：

export JAVA_HOME=/usr/java/jdk1.7.0_67

export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

export PATH=$PATH:$JAVA_HOME/bin

export JRE_HOME=/usr/java/jdk1.7.0_67/jre

 

6、使得刚刚添加到环境变量生效：

[root@iZ94lys8uuzZ rmp]# source /etc/profile

 

8、查询安装情况

[root@iZ94lys8uuzZ ~]# rpm -q jdk

jdk-1.7.0_67-fcs.x86_64

[root@iZ94lys8uuzZ ~]# rpm -qa|grep jdk

jdk-1.7.0_67-fcs.x86_64

[root@iZ94lys8uuzZ ~]# java -version

java version "1.7.0_67"

Java(TM) SE Runtime Environment (build 1.7.0_67-b01)

Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)