jdk安装

ubuntu

以 JDK 1.8.0_152 为例

下载安装包

下载地址 : http://www.oracle.com/technetwork/java/javase/downloads/index.html

上传： rz jdk-8u152-linux-x64.tar.gz

解压缩 tar -zxvf jdk-8u152-linux-x64.tar.gz
创建目录 mkdir -p /usr/local/java
移动安装包 mv jdk1.8.0_152/ /usr/local/java/
设置所有者 chown -R root:root /usr/local/java/

配置环境变量

1）配置系统环境变量
nano /etc/environment
添加如下语句
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
export JAVA_HOME=/usr/local/java/jdk1.8.0_152
export JRE_HOME=/usr/local/java/jdk1.8.0_152/jre
export CLASSPATH= $CLASSPATH:$ JAVA_HOME/lib: $JAVA_HOME/jre/lib 2）配置用户环境变量 nano /etc/profile 添加如下语句 if [ "$ PS1" ]; then
if [ " $BASH" ] && [ "$ BASH" != "/bin/sh" ]; then
# The file bash.bashrc already sets the default PS1.
# PS1='\h:\w$ '
if [ -f /etc/bash.bashrc ]; then
. /etc/bash.bashrc
fi
else
if [ "`id -u`" -eq 0 ]; then
PS1='# '
else
PS1='$ '
fi
fi
fi

export JAVA_HOME=/usr/local/java/jdk1.8.0_152
export JRE_HOME=/usr/local/java/jdk1.8.0_152/jre
export CLASSPATH= $CLASSPATH:$ JAVA_HOME/lib: $JAVA_HOME/jre/lib export PATH=$ JAVA_HOME/bin: $JAVA_HOME/jre/bin:$ PATH: $HOME/bin if [ -d /etc/profile.d ]; then for i in /etc/profile.d/*.sh; do if [ -r$ i ]; then
. $i
fi
done
unset i
fi

使用户环境变量生效

source /etc/profile

配置软连接

sudo update-alternatives --install "/usr/bin/java" "java" "/usr/local/java/jdk1.8.0_152/jre/bin/java" 1
sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/local/java/jdk1.8.0_152/bin/javac" 1
sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/local/java/jdk1.8.0_152/jre/bin/javaws" 1
sudo update-alternatives --set java /usr/local/java/jdk1.8.0_152/jre/bin/java
sudo update-alternatives --set javac /usr/local/java/jdk1.8.0_152/bin/javac
sudo update-alternatives --set javaws /usr/local/java/jdk1.8.0_152/jre/bin/javaws

测试是否安装成功

root@UbuntuBase:/usr/local/java# java -version
java version "1.8.0_152"
Java(TM) SE Runtime Environment (build 1.8.0_152-b16)
Java HotSpot(TM) 64-Bit Server VM (build 25.152-b16, mixed mode)

为其他用户更新用户环境变量

su lusifer
source /etc/profile

centos

卸载openjdk
rpm -qa | grep jdk
rpm -e --nodeps java-1.7.0-openjdk-xxxxx

安装

mkdir /root/develop
rz jdk-8u211-linux-x64.tar.gz
tar zxvf jdk-8u211-linux-x64.tar.gz
mkdir /usr/local/java
cp -r jdk-xxx /usr/local/java

环境变量

vim /etc/profile
#set java enviroment
JAVA_HOME=/usr/local/java/jdkXXX
JRE_HOME=/usr/local/java/jdkXXX/jre
CLASS_PATH=.: $JAVA_HOME/lib/dt.jar:$ JAVA_HOME/lib/tools.jar: $JRE_HOME/lib PATH=$ PATH: $JAVA_HOME/bin:$ JRE_HOME/bin
export JAVA_HOME JRE_HOME CLASS_PATH PATH