Centos7一键安装jdk1.8 shell脚本

JDK下载：

jdk-8u251-linux-x64.tar.gz

安装步骤：

1、vi install_java.sh 脚本

#!/bin/bash

#1.Check if Java is installed
if type -p java; then
	echo "Java has been installed."
	exit 0
else
#2.Installed Java 
	mkdir -p /opt/java/
	tar -zxvf ./jdk-8u251-linux-x64.tar.gz -C /opt/java/
#3.Configure environment variables
	echo "JAVA_HOME=/opt/java/jdk1.8.0_251
	PATH=\$JAVA_HOME/bin:\$PATH
	CLASSPATH=\$JAVA_HOME/jre/lib/ext:\$JAVA_HOME/lib/tools.jar
	export PATH JAVA_HOME CLASSPATH" >> /etc/profile

	source /etc/profile
	echo "setting path successful."

	java -version
	echo "installed successful."
fi

2、将 install_java.sh 脚本与安装tar包放在同一目录下，运行此脚本进行自动化安装

3、给脚本文件加执行权限

chmod +x install_java.sh

4、运行脚本文件，进行安装

./install_java.sh