$ sudo mkdir /usr/lib/java$ sudo tar zxvf jdk-7u21-linux-i586.tar.gz -C /usr/lib/java$ cd /usr/lib/java$ ls 

sudo gedit /etc/.profile

export JAVA_HOME=/usr/lib/java export JRE_HOME=${JAVA_HOME}/jre  export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  export PATH=${JAVA_HOME}/bin:$PATH  

ubuntu 14 安装 JDK