how to open a jar file in Eclipse

Since the jar file 'executes' then it contains compiled java files known as .class files. You cannot import it to eclipse and modify the code. You should ask the supplier of the "demo" for the "source code". (or check the page you got the demo from for the source code)

Unless, you want to decompile the .class files and import to Eclipse. That may not be the case for starters.

use java decompiler. http://jd.benow.ca/. you can open the jar files.

Thanks, Manirathinam.

Try JadClipse.It will open all your .class file. Add library to your project and when you try to open any object declared in the lib file it will open just like your .java file.

In eclipse->help-> marketplace -> go to popular tab. There you can find plugins for the same.

Update: For those who are unable to find above plug-in, try downloading this: https://github.com/java-decompiler/jd-eclipse/releases/download/v1.0.0/jd-eclipse-site-1.0.0-RC2.zip

Then import it into Eclipse.

If you have issues importing above plug-in, refer: How to install plugin for Eclipse from .zip