Java on CentOS

The easiest way to get Java installed on CentOS is to use the OpenJDK included in the distribution.

Setup

• Install the full JDK using Yum:

[root@ip-10-170-26-209 ~]# yum -y install java-1.6.0-openjdk-devel
.
.
.

Installed:
  java-1.6.0-openjdk-devel.x86_64 1:1.6.0.0-1.7.b09.el5                                                                                                      

Dependency Installed:
  java-1.6.0-openjdk.x86_64 1:1.6.0.0-1.7.b09.el5                                                                                                            

Complete!

Test

• Check that Java is there:

[root@ip-10-170-26-209 ~]# java -version
java version "1.6.0"
OpenJDK  Runtime Environment (build 1.6.0-b09)
OpenJDK 64-Bit Server VM (build 1.6.0-b09, mixed mode)

• Find the JAVA_HOME (for the full JDK) if you dare!:

[root@ip-10-170-26-209 ~]# which java
/usr/bin/java
[root@ip-10-170-26-209 ~]# ls -l /usr/bin/java
lrwxrwxrwx 1 root root 22 Sep 22 10:40 /usr/bin/java -> /etc/alternatives/java
[root@ip-10-170-26-209 ~]# ls -l /etc/alternatives/java
lrwxrwxrwx 1 root root 46 Sep 22 10:40 /etc/alternatives/java -> /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/java
[root@ip-10-170-26-209 ~]# ls -l /usr/lib/jvm
total 4
lrwxrwxrwx 1 root root   26 Sep 22 10:40 java -> /etc/alternatives/java_sdk
lrwxrwxrwx 1 root root   32 Sep 22 10:40 java-1.6.0 -> /etc/alternatives/java_sdk_1.6.0
drwxr-xr-x 6 root root 4096 Sep 22 10:40 java-1.6.0-openjdk-1.6.0.0.x86_64
lrwxrwxrwx 1 root root   33 Sep 22 10:40 java-1.6.0-openjdk.x86_64 -> java-1.6.0-openjdk-1.6.0.0.x86_64
lrwxrwxrwx 1 root root   34 Sep 22 10:40 java-openjdk -> /etc/alternatives/java_sdk_openjdk
lrwxrwxrwx 1 root root   21 Sep 22 10:40 jre -> /etc/alternatives/jre
lrwxrwxrwx 1 root root   27 Sep 22 10:40 jre-1.6.0 -> /etc/alternatives/jre_1.6.0
lrwxrwxrwx 1 root root   37 Sep 22 10:40 jre-1.6.0-openjdk.x86_64 -> java-1.6.0-openjdk-1.6.0.0.x86_64/jre
lrwxrwxrwx 1 root root   29 Sep 22 10:40 jre-openjdk -> /etc/alternatives/jre_openjdk
[root@ip-10-170-26-209 ~]# ls -l /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64
total 16
drwxr-xr-x 2 root root 4096 Sep 22 10:40 bin
drwxr-xr-x 3 root root 4096 Sep 22 10:40 include
drwxr-xr-x 4 root root 4096 Sep 22 10:40 jre
drwxr-xr-x 2 root root 4096 Sep 22 10:40 lib
[root@ip-10-170-26-209 ~]# export JAVA_HOME=/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64