Instructions

Obtain a Debian Package of the Oracle JVM

Use java-package to create a Debian package. See the article Creating a Debian Package of the Oracle Java SDK for instructions.

Transfer the package file, e.g. oracle-j2sdk1.7_1.7.0+update17_amd64.deb, to the machine you want to install Java 7 on.

Install Package

As root:

dpkg -i oracle-j2sdk1.7_1.7.0+update17_amd64.deb 

Set installed version of Java as the default:

root@squeezevm:~# update-alternatives --config java
There are 3 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                       Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/java-6-openjdk/jre/bin/java    1061      auto mode
  1            /usr/bin/gij-4.4                            1044      manual mode
  2            /usr/lib/jvm/j2sdk1.7-oracle/jre/bin/java   317       manual mode
  3            /usr/lib/jvm/java-6-openjdk/jre/bin/java    1061      manual mode

Press enter to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/lib/jvm/j2sdk1.7-oracle/jre/bin/java to provide /usr/bin/java (java) in manual mode.
root@squeezevm:~# # Check that the default java is the one that we chose
root@squeezevm:~# java -version
java version "1.7.0_17"
Java(TM) SE Runtime Environment (build 1.7.0_17-b02)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

Configure Tomcat to use the new version of Java

Edit /etc/default/tomcat5.5 and set JAVA_HOME to point at the new version of Java, for example:

JAVA_HOME=/usr/lib/jvm/j2sdk1.7-oracle

Restart Tomcat:

/etc/init.d/tomcat5.5 restart

Check that Tomcat is using the new version - go to /manager/html and look at the 'JVM Version' in the 'Server Information' table at the bottom of the page.

Uninstall old versions

At this point you may remove the old Java packages with 'apt-get remove <package>' or 'dpkg -r <package>'. To find out the package name of the old version run 'dpkg -S' on its directory in /usr/lib/jvm, for example:

dpkg -S /usr/lib/jvm/java-1.5.0-sun-1.5.0.22