ubuntu安装离线JDK

1、首先上Oracle官网下载JDK

http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

2、新建一个安装文件夹及拷贝源文件到文件夹下并解压

cd /usr/local
sudo mkdir java  
sudo cp -r  ~/download/jdk-7u51-linux-x64.tar.gz /usr/lib/java         
sudo tar -zxvf jdk-7u51-linux-x64.tar.gz

3、设置环境变量，用gedit打开/etc/profile文件

sudo gedit /etc/profile

在文件的最后面增加：

export JAVA_HOME=/usr/local/java/jdk1.7.0_51
export JRE_HOME=/usr/local/java/jdk1.7.0_51/jre
export PATH=$JAVA_HOME/bin:$JAVA_HOME/jre/bin:$PATH
export CLASSPATH=$CLASSPATH:.:$JAVA_HOME/lib:$JAVA_HOME/jre/lib

4、将系统默认的jdk修改过来

sudo update-alternatives --install /usr/bin/java java /usr/local/java/jdk1.7.0_51/bin/java 300
sudo update-alternatives --install /usr/bin/javac javac /usr/local/java/jdk1.7.0_51/bin/javac 300

5、查看JDK的版本，看是否安装成功

java -version