sudo update-alternatives --config java produced:
Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-7-openjdk-i386/jre/bin/java 1071 auto mode
*1 /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java 1061 manual mode
2 /usr/lib/jvm/java-7-openjdk-i386/jre/bin/java 1071 manual mode
The you can select a number to specify the default JDK.
Use sudo update-alternatives --config javac config the javac version.
How about you have installed a jdk with rpm, but it doesn't appear in the list?
Now I download Oracle JDK6 installer, jdk-6u45-linux-x64-rpm.bin, run this file,
it automatically install jdk-6u45-linux-amd64.rpm,
which is extracted from the previous installer.
But when the result of java -version is still openjdk.
So I need to find where the package installed, and set its path into JAVA_HOME.
# rpm -qa | grep jdk
java-1.7.0-openjdk-1.7.0.9-2.3.4.1.el6_3.x86_64
jdk-1.6.0_45-fcs.x86_64
java-1.6.0-openjdk-1.6.0.0-1.50.1.11.5.el6_3.x86_64
# rpm -ql java-1.6.0-openjdk-1.6.0.0-1.50.1.11.5.el6_3.x86_64
// from the file list we know the java path is: /usr/java/jdk1.6.0_45/bin
# /usr/java/jdk1.6.0_45/bin/java -version
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode)
# echo "export JAVA_HOME=/usr/java/jdk1.6.0_45" >> /etc/profile
# source /etc/profile