Is there a Java IDE written in Java?

I just got my year 9 DET laptop today at school, and there are all sorts of restrictions set in place. Somewhat annoyingly, you cannot run any executable other than the ones already installed on the system (for some reason they haven't disabled the use of Command Prompt, PowerShell, or strangely enough, regedit). They allow you to run Java executables, so I thought that would be the only way to be able to program on my crappy laptop at school (when I have finished all my work, naturally) :D

Edit:

By written in Java, I also mean that the executable, that is used to run the program, has the file extension ".jar", thus running on the JVM.

Edit 2:

I tried the DrJava IDE, and it worked great, thanks (I can compile and execute programs)! Regarding running Eclipse as through the command line using the command "java -jar "C:/Users.../org.eclipse..."". This results in an error producing a log saying file, the main error is:

MESSAGE An error occurred while automatically activating bundle org.eclipse.ui.workbench (182).

How do I fix this error (I much perfer working with Eclipse than any other IDE)?

Edit 3:

Regarding my last edit, just disregard it :D. I fixed the problem by downloading the latest version of Eclipse.