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Ubuntu Linux Install Sun Java Development Kit ( JDK ) and Java Runtime Environment ( JRE )

Posted by Vivek Gite [Last updated: July 1, 2008]

Q. How do I install Sun Java Development Kit (JDK) and Java Runtime Environment (JRE) under Ubuntu Linux? It appears that there are multiple JRE installed by default under Ubuntu. How do I select and use Sun JRE only? Can you explain steps required to set the environment to run java programs or apps?

A. Ubuntu Linux 7.10 has following packages from Sun:
=> sun-java6-bin : Sun Java Runtime Environment (JRE) 6

=> sun-java6-demo : Sun Java Development Kit (JDK) 6 demos

=> sun-java6-jdk : Sun Java Development Kit (JDK) 6

=> sun-java6-jre : Sun Java Runtime Environment (JRE) 6

Install Sun Java 6

To install proprietary Java, you must have the Multiverse repository enabled. Click on System > Administration > Software Source > Select Multisource > Close
Adding the Universe and Multiverse Repositories

Open a shell prompt (terminal) and type the following to install JDK and JRE:
$ sudo apt-get install sun-java6-bin sun-java6-jre sun-java6-jdk

Setup the default Java version

Ubuntu Linux comes with update-java-alternatives utility to updates all alternatives belonging to one runtime or development kit for the Java language. To select, Sun's JVM as provided in Ubuntu 7.10, enter:
$ sudo update-java-alternatives -s java-6-sun
You also need to edit a file called /etc/jvm. This file defines the default system JVM search order. Each JVM should list their JAVA_HOME compatible directory in this file. The default system JVM is the first one available from top to bottom. Open /etc/jvm
$ sudo vi /etc/jvm
Make sure /usr/lib/jvm/java-6-sun is added to the top of JVM list
/usr/lib/jvm/java-6-sun
At the end your file should read as follows:
/usr/lib/jvm/java-6-sun
/usr/lib/jvm/java-gcj
/usr/lib/jvm/ia32-java-1.5.0-sun
/usr/lib/jvm/java-1.5.0-sun
/usr

Save and close the file.

Setup the environment variable

You also need to setup JAVA_HOME and PATH variable. Open your $HOME/.bash_profile or /etc/profile (system wide) configuration. Open your .bash_profile file:
$ vi $HOME/.bash_profile
Append following line:
export JAVA_HOME=/usr/lib/jvm/java-6-sun
export PATH=$PATH:$JAVA_HOME/bin

Save and close the file.

Test your new JDK

Type the following command to display version:
$ java -version
Output:

java version "1.6.0_03"
Java(TM) SE Runtime Environment (build 1.6.0_03-b05)
Java HotSpot(TM) Server VM (build 1.6.0_03-b05, mixed mode) 

Try HelloWorld.java - first java program

$ vi HelloWorld.java
Append code:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Save and close the file. Compile HelloWorld.java and execute program by typing following two instructions:
$ javac HelloWorld.java
$ java HelloWorld

Output:

Hello, World!

Further readings:

  • Official Sun Java tutorial - The Java Tutorials are practical guides for programmers who want to use the Java programming language to create applications. They include hundreds of complete, working examples, and dozens of lessons. Groups of related lessons are organized into "trails".
  • man pages java, javac

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Discussion on This FAQ

  1. Miguel Says:

    When I execute:
    $ javac HelloWorld.java

    Show me this error:
    El programa «javac» puede encontrarse en los siguientes paquetes:
    * jikes-sun
    * jikes-sablevm
    * gcj-4.2
    * kaffe
    * ecj
    * java-gcj-compat-dev
    * j2sdk1.4
    * jikes-classpath
    * jikes-gij
    * gcj-4.1
    * sun-java5-jdk
    * jikes-kaffe
    * sun-java6-jdk
    Pruebe: sudo apt-get install
    bash: javac: orden no encontrada

    Thanks, any help would be greatly appreciated.

  2. Tor Says:

    Miguel:

    I had the same problem. I solved it by running:
    sudo update-java-alternatives -s java-6-sun

    You will also need to install sun-java6-jdk if you have not done that already

  3. ahmed Says:

    WinRAR en Java Sun JDk 6 download

  4. jose Says:

    thanks. works

  5. dru Says:

    $ sudo apt-get install sun-java6-bin sun-java6-jre

    should be

    $ sudo apt-get install sun-java6-bin sun-java6-jre sun-java6-jdk

    to solve the compile problem

  6. Pewo Says:

    thx dru (:

  7. vivek Says:

    Thanks for the heads up. The faq has been updated.

  8. pall Says:

    Thanks yeah!!!! I could install java… I m not a newbie but was still facing lots of problem… and all was resolved following these simple steps religiously….

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