JDK安装（Linux版）

傷城~ 2023-06-16 10:39 51阅读 0赞

## 卸载系统中自带JDK ##

> 如果系统中并没有安装jdk，可以忽略直接下一步安装

查看系统使用中jdk版本：

java -version

[root@localhost jdk1.8.0_231]# java -version
    openjdk version "1.8.0_232"
    OpenJDK Runtime Environment (build 1.8.0_232-b09)
    OpenJDK 64-Bit Server VM (build 25.232-b09, mixed mode)

查看所有已安装java相关的软件包：

rpm -qa | grep java

[root@localhost jdk1.8.0_231]# rpm -qa | grep java
    java-1.7.0-openjdk-headless-1.7.0.241-2.6.20.0.el7_7.x86_64
    java-1.8.0-openjdk-headless-1.8.0.232.b09-0.el7_7.x86_64
    java-1.8.0-openjdk-1.8.0.232.b09-0.el7_7.x86_64
    java-1.7.0-openjdk-1.7.0.241-2.6.20.0.el7_7.x86_64
    tzdata-java-2019c-1.el7.noarch
    javapackages-tools-3.4.1-11.el7.noarch
    python-javapackages-3.4.1-11.el7.noarch

如上命令结果中可以发现使用中的jdk版本即`java-1.8.0-openjdk-1.8.0.232.b09-0.el7_7.x86_64`，但为了防止其它已安装jdk影响，建议把所有openjdk给删掉，如下：

[root@localhost jdk1.8.0_231]# rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.232.b09-0.el7_7.x86_64
    [root@localhost jdk1.8.0_231]# rpm -e --nodeps java-1.8.0-openjdk-1.8.0.232.b09-0.el7_7.x86_64
    [root@localhost jdk1.8.0_231]# rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.241-2.6.20.0.el7_7.x86_64
    [root@localhost jdk1.8.0_231]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.241-2.6.20.0.el7_7.x86_64

## 安装JDK [（官方下载JDK）][JDK] ##

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**在指定安装目录（我习惯放在`/usr/softinstall/`目录下）解压：**

tar -xzvf jdk-8u231-linux-x64.tar.gz

**jdk的tar.gz版不需要安装，只需要配置环境变量即可：**

vim /etc/profile

export JAVA_HOME=/usr/softinstall/jdk1.8.0_231
    export JRE_HOME=$JAVA_HOME/jre
    
    export CLASSPATH=$CLASSPATH:$JAVA_HOME/lib:$JRE_HOME/lib
    export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

source /etc/profile

**测试：**

java -version

[root@lee000 jdk1.8.0_231]# java -version
    java version "1.8.0_231"
    Java(TM) SE Runtime Environment (build 1.8.0_231-b11)
    Java HotSpot(TM) 64-Bit Server VM (build 25.231-b11, mixed mode)

[JDK]: https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
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