CentOS - 安装jdk（卸载openjdk）

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本文链接： https://blog.csdn.net/nangy2514/article/details/99857474

一、卸载openjdk

1. 查看openjdk版本

[nangy@nangy-vm ~]$ java -version
openjdk version "1.8.0_222"
OpenJDK Runtime Environment (build 1.8.0_222-b10)
OpenJDK 64-Bit Server VM (build 25.222-b10, mixed mode)

[nangy@nangy-vm ~]$ rpm -qa | grep java
java-1.7.0-openjdk-headless-1.7.0.231-2.6.19.1.el7_6.x86_64
javapackages-tools-3.4.1-11.el7.noarch
java-1.8.0-openjdk-headless-1.8.0.222.b10-0.el7_6.x86_64
python-javapackages-3.4.1-11.el7.noarch
tzdata-java-2019b-1.el7.noarch
java-1.8.0-openjdk-1.8.0.222.b10-0.el7_6.x86_64
java-1.7.0-openjdk-1.7.0.231-2.6.19.1.el7_6.x86_64

2. 卸载openjdk

使用rpm -e --nodeps进行强制卸载，将所有的openjdk都nodeps掉

[nangy@nangy-vm ~]$ sudo rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.231-2.6.19.1.el7_6.x86_64
[nangy@nangy-vm ~]$ sudo rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.222.b10-0.el7_6.x86_64
[nangy@nangy-vm ~]$ sudo rpm -e --nodeps java-1.8.0-openjdk-1.8.0.222.b10-0.el7_6.x86_64
[nangy@nangy-vm ~]$ sudo rpm -e --nodeps java-1.7.0-openjdk-1.7.0.231-2.6.19.1.el7_6.x86_64

# 验证一下
[nangy@nangy-vm ~]$ java -version
bash: /usr/bin/java: 没有那个文件或目录

二、下载jdk1.8

官网下载 | JDK 8u211

三、安装jdk1.8

方法一、手动配置

1. 准备jdk文件

先下载.tar.gz压缩包

[nangy@nangy-vm ~]$ sudo mkdir /opt/java
[nangy@nangy-vm ~]$ ll /opt/ | grep java
drwxr-xr-x. 2 root root  6 8月  20 16:47 java
[nangy@nangy-vm ~]$ cd /opt/java/
[nangy@nangy-vm java]$ sudo cp /mnt/hgfs/VMware共享文件/software/jdk-8u211-linux-x64.tar.gz -R /opt/java/
[nangy@nangy-vm java]$ ll
总用量 190424
-rwxr-xr-x. 1 root root 194990602 8月  20 16:48 jdk-8u211-linux-x64.tar.gz
[nangy@nangy-vm java]$ sudo tar -zxvf jdk-8u211-linux-x64.tar.gz 
[nangy@nangy-vm java]$ cd jdk1.8.0_211/
[nangy@nangy-vm jdk1.8.0_211]$ pwd
/opt/java/jdk1.8.0_211

2. 配置/etc/profile

[nangy@nangy-vm jdk1.8.0_211]$ sudo vim /etc/profile

• 将变量配置添加到/etc/profile尾部

# JAVA_HOME
export JAVA_HOME=/opt/java/jdk1.8.0_211
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$JAVA_HOME/bin:$PATH

3. 使/etc/profile生效

# 切换到root用户
[nangy@nangy-vm jdk1.8.0_211]$ su
[root@nangy-vm jdk1.8.0_211]$ source /etc/profile

[root@nangy-vm jdk1.8.0_211]$ java -version
java version "1.8.0_211"
Java(TM) SE Runtime Environment (build 1.8.0_211-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.211-b12, mixed mode)

方法二、安装二进制包

1. 安装rpm包

先下载.rpm二进制包

[nangy@nangy-vm 下载]$ sudo rpm -ivh jdk-8u211-linux-x64.rpm 

[nangy@nangy-vm 下载]$ java -version
java version "1.8.0_211"
Java(TM) SE Runtime Environment (build 1.8.0_211-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.211-b12, mixed mode)

2. 配置/etc/profile

[nangy@nangy-vm 下载]$ sudo vim /etc/profile

• 将变量配置添加到/etc/profile尾部
  通过rpm包安装的jdk路径是/usr/java/jdk1.8.0_211-amd64

# JAVA_HOME
export JAVA_HOME=/usr/java/jdk1.8.0_211-amd64
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$JAVA_HOME/bin:$PATH

3. 使/etc/profile生效

# 切换到root用户
[nangy@nangy-vm 下载]$ su
[root@nangy-vm 下载]$ source /etc/profile

[root@nangy-vm 下载]$ java -version
java version "1.8.0_211"
Java(TM) SE Runtime Environment (build 1.8.0_211-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.211-b12, mixed mode)

题外话：安装openJDK

# 查看可用的JDK软件包列表
[nangy@nangy-vm ~]$ sudo yum search java | grep -i --color JDK
# 输入以下命令yum安装openjdk
[nangy@nangy-vm ~]$ sudo yum install java-1.8.0-openjdk.x86_64 java-1.8.0-openjdk-devel.x86_64

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