Go to your . minecraft, then versions, open a version folder and open the jar in there.
Is the Minecraft source code available?
Minecraft is closed source with the exception of its brigadier command parser library, and its "data fixer upper" tool. Seems they have a few other releases on their Github. Of course Minecraft is built in Java, which makes it easy to decompile.
How do you get the Java code from Minecraft?
Instructions
- Create an account at minecraft.net/redeem, or if you have an account just log in.
- Enter the redemption code when prompted after log in.
- Choose your Minecraft player name.
- Download the game.
- Start the game and enjoy Minecraft!
- Keep PIN code for future reference.