Introduction

I had installed JDK 6.0 update 31 in an earlier post. However, I now need to write a Java application that requires the features available in JDK 7.

In this post, I will install JDK 7 update 5 as a secondary JDK, while JDK 6.0 u31 will be the primary JDK. It’s perfectly normal to have multiple JDKs on a single machine to support the requirements of different applications. Fortunately, it’s easy to use a different JDK on a per application basis.

Download

I have a 64 bit version of Ubuntu 12.04 LTS installed, so the instructions below only apply to this OS.

1. Download the Java JDK from http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1637583.html.
2. Click Accept License Agreement
3. Click dk-7u5-linux-x64.tar.gz
4. Login to Oracle.com with your Oracle account
5. Download the JDK to your ~/Downloads directory
6. After downloading, open a terminal, then enter the following commands.

Installation

Open a terminal, then enter the following commands:

cd ~/Downloads

tar -xzf jdk-7u5-linux-x64.tar.gz

Note:
The jvm directory is used to organize all JDK/JVM versions in a single parent directory. As this is our 2nd JDK, we’ll assume that the jvm directory already exists.

sudo mv jdk1.7.0_05 /usr/lib/jvm

The next 3 commands are split across 2 lines per command due to width limits in the blog’s theme.

sudo update-alternatives --install "/usr/bin/java" "java"  \
	"/usr/lib/jvm/jdk1.7.0_05/bin/java" 2

sudo update-alternatives --install "/usr/bin/javac" "javac"  \
	"/usr/lib/jvm/jdk1.7.0_05/bin/javac" 2

sudo update-alternatives --install "/usr/bin/javaws" "javaws"  \
	"/usr/lib/jvm/jdk1.7.0_05/bin/javaws" 2

sudo update-alternatives --config java

You will see output similar to the following (although it’ll differ on your system). Read through the list and find the number for the Oracle JDK installation (/usr/lib/jvm/jdk1.7.0_05/bin/java)

There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                               Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/jdk1.7.0_05/bin/java   2         auto mode
  1            /usr/lib/jvm/jdk1.6.0_31/bin/java   1         manual mode
  2            /usr/lib/jvm/jdk1.7.0_05/bin/java   2         manual mode

Press enter to keep the current choice[*], or type selection number:

On my system I did entered 1 to keep JDK 1.6.0 u31 as my primary JDK (change the number that is appropriate for your system). To enter 1, press 1 on the keyboard, then press Enter.

sudo update-alternatives --config javac

There are 2 choices for the alternative javac (providing /usr/bin/javac).

  Selection    Path                                Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/jdk1.7.0_05/bin/javac   2         auto mode
  1            /usr/lib/jvm/jdk1.6.0_31/bin/javac   1         manual mode
  2            /usr/lib/jvm/jdk1.7.0_05/bin/javac   2         manual mode

Press enter to keep the current choice[*], or type selection number:

I entered 1 then pressed Enter to keep JDK 1.6.0 u31 as my primary javac command.

sudo update-alternatives --config javaws

There are 2 choices for the alternative javaws (providing /usr/bin/javaws).

  Selection    Path                                 Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/jdk1.7.0_05/bin/javaws   2         auto mode
  1            /usr/lib/jvm/jdk1.6.0_31/bin/javaws   1         manual mode
  2            /usr/lib/jvm/jdk1.7.0_05/bin/javaws   2         manual mode

Press enter to keep the current choice[*], or type selection number:

I entered 1 then pressed Enter to keep JDK 1.6.0 u31 as my primary javaws command.

As a final step, let’s test each of the commands to ensure everything is setup correctly.

java -version

The output should be:
java version "1.6.0_31"
Java(TM) SE Runtime Environment (build 1.6.0_31-b04)
Java HotSpot(TM) 64-Bit Server VM (build 20.6-b01, mixed mode)

javac -version

The output should be:
javac 1.6.0_31

javaws -version

The output should be:
Java(TM) Web Start 1.6.0_31, which is followed by a long usage message.

That’s it, the JDK 7 u5 is installed.

Image may be NSFW.
Clik here to view.

Image may be NSFW.
Clik here to view.