You are trying to install the sun java development documentation, I presume this is what you wish to do? If it is not what you want you should do sudo apt-get remove --purge sun-java5-doc
If you do want the sun JDK documentation read on, I have just been through this myself so I may be able to help.
go to the link in the terminal http://java.sun.com/j2se/1.5.0/download.html and download the file jdk-1_5_0-doc.zip
When you have downloaded the file to wherever you chose to download it to, copy it to /tmp
you can do this using nautilus or the terminal.
then open a terminal and issue the commands as follows
cd /tmp
sudo chown root:root jdk-1_5_0-doc.zip
sudo apt-get install sun-java5-doc