1、查找是否已安装JDK

rpm -qa | grep java#显示java-1.8.0-openjdk-1.8.0.102-4.b14.el7.x86_64tzdata-java-2016g-2.el7.noarchjavapackages-tools-3.4.1-11.el7.noarchjava-1.8.0-openjdk-headless-1.8.0.102-4.b14.el7.x86_64java-1.7.0-openjdk-headless-1.7.0.111-2.6.7.8.el7.x86_64java-1.7.0-openjdk-1.7.0.111-2.6.7.8.el7.x86_64python-javapackages-3.4.1-11.el7.noarch

2、卸载自带的JDK（rpm或yum命令[yum -y remove xxx]）

rpm -e --nodeps java-1.8.0-openjdk-1.8.0.102-4.b14.el7.x86_64rpm -e --nodeps tzdata-java-2016g-2.el7.noarchrpm -e --nodeps javapackages-tools-3.4.1-11.el7.noarchrpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.102-4.b14.el7.x86_64rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.111-2.6.7.8.el7.x86_64rpm -e --nodeps java-1.7.0-openjdk-1.7.0.111-2.6.7.8.el7.x86_64rpm -e --nodeps python-javapackages-3.4.1-11.el7.noarch

3、安装JDK

tar -xzvf jdk-8u111-linux-x64.tar.gz

vi /etc/profile

追加：

    JAVA_HOME=/app/jdk1.8.0_111

    export PATH=$JAVA_HOME/bin:$PATH

source /etc/profile

    echo "export JAVA_HOME=/app/jdk1.8.0_111" >> /etc/profile

4、验证

java -version