用yum安装的JDK如何编写/etc/profile文件的环境变量

linux下如何查看JDK的安装路径

which java

/usr/bin/java

ls -lrt /usr/bin/java

lrwxrwxrwx. 1 root root 22 Aug 17 15:12 /usr/bin/java -> /etc/alternatives/java

ls -lrt /etc/alternatives/java

lrwxrwxrwx. 1 root root 46 Aug 17 15:12 /etc/alternatives/java -> /usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java

cd /usr/lib/jvm
配置java的环境变量

export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk.x86_64
export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar 
export PATH=$PATH:$JAVA_HOME/bin 

使环境变量生效

source /etc/profile