Hacking Mule Application - View Source Code

Introduction

To become a real good Mule developer, we need to understand the source code of Mule connectors, components, and other internal source code. This helps us to learn the internal data model and interfaces of Mule classes. I have written a blog on how to compile and install the ECD in Anypoint Studio. However, that building system is broken for Mule 4. Hopefully, it will be fixed soon.

This article demonstrate another way to view the source code. It is not the best solution yet, but it help. The idea is to use Eclipse IDE and ECD plugin to review the java source code.

ECD is so far the best Java Decompiler available for Eclipse. The details can be found at here

Install Eclipse & ECD Plugin

First download the Eclipse EE from this site. Second, create a java project. Third, install ECD Eclipse Plugin. go to Eclipse Market Place of ECD
Drag the install to your project.

Now to preferences, you should see the Decompiler under Java as shown belog:

Fourth, import jar archive. right click the project --> select Achive File

browser the file from your local maven repository. In my case, it is at .m2/repository/org/mule/connectors/mule-http-connector/1.5.3.
Import the jar file to the newly created project. Drill down the classed you are interested as shown in the following snapshot:

Note that you have to chose the decompiler by right click java class --> open with, select as shown below:

At this point, we can review the source code. The next step is to decompiler the whole jar file and rebuild it with source. In this we can debug the source code and modify the behavior of the connectors. I will cover the procedure later.