How to Open a JAR File in Eclipse (Add to Classpath or Decompile)

Add a JAR as a library in Eclipse, attach source, browse its classes, or decompile it online — step-by-step for all common Eclipse JAR workflows.

Use Case 1: Add a JAR as a Project Dependency

Use Case 2: Attach Source to a JAR (See Javadoc and Source)

Use Case 3: Browse Classes Inside a JAR

Use Case 4: Decompile a JAR to Read Its Source

Use Case 5: Open a Runnable JAR

Troubleshooting

Summary