I accidently opened a java file with something else, How do I change it back?

A few months ago I recently got Minecraft for PC and I was doing al these things with forge and mods when I accidently opened the java file thing with something else. By java file thing its when you download a mod and it shows the java symbol. So if anyone knows how to turn it back please help me it didn't bother me at first, but now its important and I need to change it.

Find a java file that opens with the wrong program using the Windows Explorer. Right-click on the file and choose "Open With", and at the bottom of that list is "Choose Default Program…". Click that and pick the application that should open it instead. If you leave "Always use the selected program…" checked, that will remember your choice for all files of that type.

For a.java or.jav source file, that should be either a text editor like Notepad++ (or plain Notepad, if you don't have something better) or an IDE like Eclipse or NetBeans if you have that installed.

If it's a.jar file, try to find "Java SE Platform Binary" and hope that whatever process changed the assignment didn't delete that choice or change the command line setup. Starting with WIndows 7 (maybe Vista too), recreating command line options for a filetype isn't easy to do.

If it is still of type.java, it shouldn't matter…

The easiest way to fix this is to uninstall and reinstall Java.