How To Install JAVA ( OpenJDK ) on Ubuntu

In this article I am going to install JAVA (OpenJDK) on Ubuntu 12.04 LTS system. Use below simple steps to install. read more about java

Step 1: Search OpenJDK Packages

Use apt-cache command to search available java version to install.

 $ apt-cache search openjdkdefault-jdk-doc - Standard Java or Java compatible Development Kit (documentation)default-jdk - Standard Java or Java compatible Development Kitdefault-jre - Standard Java or Java compatible Runtimedefault-jre-headless - Standard Java or Java compatible Runtime (headless)freemind - Java Program for creating and viewing Mindmapsicedtea-7-jre-jamvm - Alternative JVM for OpenJDK, using JamVMicedtea-7-plugin - web browser plugin based on OpenJDK and IcedTea to execute Java appletsjtreg - Regression Test Harness for the OpenJDK platformopenjdk-7-dbg - Java runtime based on OpenJDK (debugging symbols)openjdk-7-demo - Java runtime based on OpenJDK (demos and examples)openjdk-7-doc - OpenJDK Development Kit (JDK) documentationopenjdk-7-jdk - OpenJDK Development Kit (JDK)openjdk-7-jre - OpenJDK Java runtime, using Hotspot JITopenjdk-7-jre-headless - OpenJDK Java runtime, using Hotspot JIT (headless)openjdk-7-jre-lib - OpenJDK Java runtime (architecture independent libraries)openjdk-7-jre-zero - Alternative JVM for OpenJDK, using Zero/Sharkopenjdk-7-source - OpenJDK Development Kit (JDK) source filesuwsgi-app-integration-plugins - plugins for integration of uWSGI and applicationicedtea-7-jre-cacao - Transitional package for obsolete Cacao JVM for OpenJDKjava-package - Utility for creating Java Debian packages

As per above output you can see openjdk-7-jdk is available in package manager.

Step 2: Install JAVA (OpenJDK)

Use below command to install JAVA using package manager.

$ sudo apt-get install openjdk-7-jdk

Step 3: Verify JAVA Version

After installation of Java use below command to verify the installed version of JAVA.

$ java -versionjava version "1.7.0_51"OpenJDK Runtime Environment (IcedTea 2.4.4) (7u51-2.4.4-0ubuntu0.12.04.2)OpenJDK Client VM (build 24.45-b08, mixed mode, sharing)root@ubuntu:~# 

Step 4: Setup JAVA_HOME Environment Variable

Its the best practice to set Java environment variable after installing java. To setup JAVA_HOME add following line to ~/.bashrc file, Path may be differ with your system architecture.

$ echo "export JAVA_HOME=\"/usr/lib/jvm/java-7-openjdk-i386/\"" >> ~/.bashrc$ source ~/.bashrc

Use following command to check the environment value

$ echo $JAVA_HOME/usr/lib/jvm/java-7-openjdk-i386/