1.到http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html下载相应的jdk
2.解压放到某一位置，我是放在/home/zhongkeli/tools/JDK1_7
3.打开bashrc，vim ~/.bashrc
4.在bashrc最后面添加
export JAVA_HOME=/home/zhongkeli/tools/JDK1_7
export JRE_HOME=/home/zhongkeli/tools/JDK1_7/jre
export CLASSPATH=.:$CLASSPATH:$JAVA_HOME/lib:$JAVA_HOME/jre/lib
export PATH=$JAVA_HOME/bin:$JAVA_HOME/jre/bin:$PATH:$HOME/bin
5.更新一下,source ~/.bashrc