1.檢查一下系統中是否已安裝jdk

[[email protected] local]# java -version

如果顯示如下，則需要解除安裝。

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)

檢視已安裝的jdk安裝包

[[email protected] local]# rpm -qa | grep java
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
 

解除安裝openjdk

[[email protected] local]# rpm -e --nodeps tzdata-java-2016g-2.el7.noarch
[[email protected] local]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.111-2.6.7.8.el7.x86_64
[[email protected] local]# rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.111-2.6.7.8.el7.x86_64
[[email protected]
 
 local]# rpm -e --nodeps java-1.8.0-openjdk-1.8.0.102-4.b14.el7.x86_64
[[email protected] local]# rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.102-4.b14.el7.x86_64

2.安裝新的jdk

使用xfpt工具將安裝包 jdk-8u161-linux-x64.tar.gz上傳到 /usr/local/ 目錄，將其減壓。

[[email protected] local]# tar -zxvf jdk-8u161-linux-x64.tar.gz
 

配置環境變數

[[email protected] local]# vi /etc/profile

在最後新增如下程式碼

export JAVA_HOME=/usr/local/jdk-8u161-linux-x64  
export JRE_HOME=${JAVA_HOME}/jre  
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  
export  PATH=${JAVA_HOME}/bin:$PATH

使配置生效

[[email protected] local]# source /etc/profile

3.檢視jdk版本，顯示如下資訊表示jdk安裝配置完成。

[[email protected] local]# java -version
java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)