Java, Software | How to install java 6 on CentOS 5 and remove other JDK, JRE version?

At the time of writing this article Java 6 (update 37) was available at http://www.java.com/en/download/manual_v6.jsp

First set up a folder where you want to install java

$ cd /opt

$ wget http://download.oracle.com/otn-pub/java/jdk/6u37-b06/jdk-6u37-linux-x64-rpm.bin

$ chmod +x jdk-6u37-linux-x64-rpm.bin

$ ./jdk-6u37-linux-x64-rpm.bin

Check the current installation of java

$ rpm -qa | grep jre

$ rpm -qa | grep jdk

$ rpm -qa | grep openjdk

There may be scenarios where your OS might have multiple copies of java jre’s or jdk’s. To find which one is being used you can issue the following command in CentOs

$ alternatives –display java

To configure one of the distribution you can use

$ alternatives –config java

Following commands need to go in order to complete the proper setup of java (which is often forgotten)

$ alternatives –install /usr/bin/java java /usr/java/jdk1.6.0_37/jre/bin/java 20000
$ alternatives –install /usr/bin/javaws javaws /usr/java/jdk1.6.0_37/jre/bin/javaws 20000
$ alternatives –install /usr/bin/javac javac /usr/java/jdk1.6.0_37/bin/javac 20000
$ alternatives –install /usr/bin/jar jar /usr/java/jdk1.6.0_37/bin/jar 20000
$ alternatives –set java /usr/java/jdk1.6.0_37/jre/bin/java
$ alternatives –set javaws /usr/java/jdk1.6.0_37/jre/bin/javaws
$ alternatives –set javac /usr/java/jdk1.6.0_37/bin/javac
$ alternatives –set jar /usr/java/jdk1.6.0_37/bin/jar

To check the java version

$ java -version

java version “1.6.0_37”
Java(TM) SE Runtime Environment (build 1.6.0_37-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01, mixed mode)