Configuration JAVA Running on Redhat Linux or Centos

Having Redhat or Centos Linux installed and running, by default the Operating system might come with an older Java Version, like 1.4.x

Download just the Java Binary self extractable:

http://www.java.com/en/download/linux_manual.jsp

  • Create a new directory in /usr: mkdir /usr/java
  •  copy jrebinary file file to /usr/java
  • Run and complete the java installation: /usr/java/jre-1_5_0_14-linux-i586-rpm.bin
  • Create the java environment variables and make sure they are loaded when a session is open. To do that:
  • Create a new file java.sh in the profile.d directory: vi /etc/profile.d/java.sh
  • Type the following text:

#!/bin/sh
JAVA_HOME=/usr/java/jre1.5.0_15
export JAVA_HOME
JAVA_BIN=$JAVA_HOME/bin
CLASSPATH=$CLASSPATH:$JAVA_HOME:$JAVA_HOME/lib
PATH=$JAVA_BIN:$PATH
export JAVA_BIN CLASSPATH PATH

  • Save the file and exit the editor
  • Close the session and open it again. To make sure the environment variables are created, type the command: export and make sure that the JAVA_HOME and JAVA_BIN are listed.
  • Type the following command to add the installed java version to the RedHat configuration:

/usr/sbin/alternatives –install /usr/bin/java java /usr/java/jre1.5.0_15/bin/java 2

  • Type the following command: /usr/sbin/alternatives –config java
  • The following text will be displayed:

Selection     Command
———————————————–
+ 1 /usr/lib/jvm/jre-1.5.0-gcj/bin/java
2 /usr/java/jre1.5.0_15/bin/java

Enter to keep the current selection[+], or type selection number:

  • Type 2 and press Enter.
  • To verify that RedHat is now using the correct version of Java, type: java -version and make sure that the JRE 1.5.0.15 is used.

 

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