How to Recompile a JAR File

Learn how to recompile a JAR file after modifying its source — decompile, edit, recompile with javac, and repackage with the jar command.

Step 1: Decompile the JAR to Java Source

Step 2: Edit the Java Source

Step 3: Recompile With `javac`

Step 4: Repackage Into a JAR

Step 5: Test the Recompiled JAR

If the JAR Is Signed

Summary