Linux虚拟机一键安装JDK脚本

此脚本书写时仅为个人使用，如需使用可以修改，本篇内容为讲解需要修改的内容，完整脚本如下

#!/bin/bash
# 脚本存放位置 /opt/modules/
# 压缩包存放位置 /opt/modules/jdk-8u162-linux-x64.tar.gz
# 安装目录  /opt/installs
# 安装版本  jdk1.8.0_162

CRTDIR=$(pwd)

# 此处为压缩包存放位置
jdkTargz="/opt/modules/jdk-8u162-linux-x64.tar.gz"
echo "${jdkTargz}"

# 检查原先是否已配置java环境变量
checkExist(){
 jdk1=$(grep -n "export JAVA_HOME=.*" /etc/profile | cut -f1 -d':')
    if [ -n "$jdk1" ];then
        echo "JAVA_HOME已配置，删除内容"
        sed -i "${jdk1}d" /etc/profile
    fi
 jdk2=$(grep -n "export CLASSPATH=.*\$JAVA_HOME.*" /etc/profile | cut -f1 -d':')
    if [ -n "$jdk2" ];then
        echo "CLASSPATH路径已配置，删除内容"
        sed -i "${jdk2}d" /etc/profile
    fi
 jdk3=$(grep -n "export PATH=.*\$JAVA_HOME.*" /etc/profile | cut -f1 -d':')
    if [ -n "$jdk3" ];then
        echo "PATH-JAVA路径已配置，删除内容"
        sed -i "${jdk3}d" /etc/profile
    fi
}

# 查询是否有jdk.tar.gz
if [ -e $jdkTargz ];
then

echo "— — 存在jdk压缩包 — —"
 echo "正在解压jdk压缩包..."
 tar -zxvf ${jdkTargz} -C /opt/installs
 if [ -e "/opt/install/jdk" ];then
 echo "存在/opt/install/jdk，删除..."
 rm -rf /opt/install/jdk
 fi
mv /opt/installs/jdk1.8.0_162 /opt/installs/jdk
 # 检查配置信息
 checkExist 
 echo "---------------------------------"
 echo "正在配置jdk环境..."
 sed -i '$a export JAVA_HOME=/opt/installs/jdk' /etc/profile
 sed -i '$a export PATH=$PATH:$JAVA_HOME/bin' /etc/profile
 echo "---------------------------------"
 echo "JAVA环境配置已完成..."
 echo "---------------------------------"
 echo "正在重新加载配置文件..."
 echo "---------------------------------"
 source /etc/profile
 echo "配置版本信息如下："
 java -version
else
 echo "未检测到安装包，请将安装包放到/opt目录下"
fi