Make sure the multiverse repository is enabled. (See How do I add Universe and Multiverse?)

Go to http://java.sun.com/j2se/1.5.0/download.jsp and click on “Download JRE 5.0 Update 4”. Ensure you do not choose the link with the NetBeans bundle.

	At the time of this writing J2SE is at version 5.0 Update 4. This is subject to change. If you do not see this version on Sun's website, download the newest version displayed.

You must first accept the licence, then click on “Linux self-extracting file” (jre-1_5_0_04-linux-i586.bin). Save this file to your hard drive.

Install the java-package package with Synaptic (See How do I use Synaptic to install packages?)

Make the downloaded file executable. At the command line, change to the directory where you downloaded the file, and type

chmod +x jre-1_5_0_04-linux-i586.bin

To install JRE, run the downloaded file. Type

fakeroot make-jpkg jre-1_5_0_04-linux-i586.bin

dpkg -i sun-j2re1.5_1.5.0+update04_i386.deb