redhat7.2

#java -version

openjdk1.8


#rpm -i jdk-7u80-linux-x64.rpm

#updatedb;locate java

#alternatives --install /usr/bin/java java /usr/java/default/bin/java 0

#alternatives --config java

共有 2 个提供“java”的程序。


  选项    命令

-----------------------------------------------

*+ 1           /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64/jre/bin/java

  2           /usr/java/default/bin/java


按 Enter 保留当前选项[+]，或者键入选项编号：2


#java -version

java version "1.7.0_80"


#vim /etc/profile.d/jdk.sh

JAVA_HOME=/usr/java/default

PATH=$PATH:$JAVA_HOME/bin

#source /etc/profile

#echo $PATH

#jps 

http://www.51testing.com/html/57/121957-225614.html

The RPM package creates two links: /usr/java/latest and /usr/java/default.
The /usr/java/latest link will always point to the version of Java that is considered the latest version. Subsequent upgrades of the package will overwrite this value if it is not the latest version.

 
By default, /usr/java/default points to /usr/java/latest.

 

 

就可以知道 其实JAVA_HOME 设置为  /usr/java/default 就可以了