1. 检查一下系统中的jdk版本
```bash
[root@localhost software]# java -version
```
显示:
```bash
openjdk version "1.8.0_102" OpenJDK Runtime Environment (build 1.8.0_102-b14) OpenJDK 64-Bit Server VM (build 25.102-b14, mixed mode)
```
2. 检测jdk安装包
```bash
[root@localhost software]# rpm -qa | grep java
```
显示:
```bash
java-1.7.0-openjdk-1.7.0.111-2.6.7.8.el7.x86_64 python-javapackages-3.4.1-11.el7.noarch tzdata-java-2016g-2.el7.noarch javapackages-tools-3.4.1-11.el7.noarch java-1.8.0-openjdk-1.8.0.102-4.b14.el7.x86_64 java-1.8.0-openjdk-headless-1.8.0.102-4.b14.el7.x86_64 java-1.7.0-openjdk-headless-1.7.0.111-2.6.7.8.el7.x86_64
```
3. 卸载openjdk
```bash
[root@localhost software]# rpm -e --nodeps tzdata-java-2016g-2.el7.noarch [root@localhost software]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.111-2.6.7.8.el7.x86_64 [root@localhost software]# rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.111-2.6.7.8.el7.x86_64 [root@localhost software]# rpm -e --nodeps java-1.8.0-openjdk-1.8.0.102-4.b14.el7.x86_64 [root@localhost software]# rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.102-4.b14.el7.x86_64
```
或者使用
```bash
[root@localhost jvm]# yum remove *openjdk*
```
之后再次输入rpm -qa | grep java 查看卸载情况:
```bash
[root@localhost software]# rpm -qa | grep java python-javapackages-3.4.1-11.el7.noarch javapackages-tools-3.4.1-11.el7.noarch
```
4. 安装新的jdk
首先到jdk官网上下载你想要的jdk版本。官网由于证书问题wget 不能直接下载,需要加忽略证书和请求头。这里下载的jdk-8u201-linux-x64.tar.gz版本的jdk。如果下载失败可用下载链接:
[http://apache.apooloo.cn/#/down/f1b54d77df533af9d9de55cf3f4e2cea](http://apache.apooloo.cn/#/down/f1b54d77df533af9d9de55cf3f4e2cea)
```bash
wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" https://download.oracle.com/otn-pub/java/jdk/8u201-b09/42970487e3af4f5aa5bca3f542482c60/jdk-8u201-linux-x64.tar.gz
```
在/usr/local下创建java文件夹,并解压jdk-8u131-linux-x64.tar.gz安装包到该文件夹下。
```bash
[root@localhost software]# mkdir /usr/local/java
[root@localhost software]# tar -xvf jdk-8u131-linux-x64.tar.gz /usr/local/java
```
5. 设置环境变量
在/etc/profile中添加如下内容:
```
export JAVA_HOME=/usr/local/java/jdk1.8.0_131
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH
```
6. 执行profile文件
```bash
[root@localhost software]# source /etc/profile
```
这样可以使配置不用重启即可立即生效。
7. 检查新安装的jdk
```bash
[root@localhost software]# java -version
```
显示:
```bash
java version "1.8.0_201"Java(TM) SE Runtime Environment (build 1.8.0_201-b09)Java HotSpot(TM) 64-Bit Server VM (build 25.201-b09, mixed mode)
```
到此为止,整个安装过程结束

linux-安装JDK1.8