How to generate UML diagrams (especially sequence diagrams) from Java code?

What is your codebase? Java or C++?

eUML2 for Java is a powerful UML modeler designed for Java developper in Eclipse. The free edition can be used for commercial use. It supports the following features:

• CVS and Team Support
• Designed for large project with multiple and customizable model views
• Helios Compliant
• Real-time code/model synchronization
• UML2.1 compliant and support of OMG XMI
• JDK 1.4 and 1.5 support

• The commercial edition provides:

• Advanced reversed engineering

• Powerful true dependency analyze tools
• UML Profile and MDD
• Database tools
• Customizable template support

I would recommend EclipseUML from Omondo for general usage, although I did experience some problems a few months back, with my web projects. They had a free edition at one point in time, but that is supposedly no longer promoted.

If you are really keen on reverse engineering sequence diagrams from source code, I would recommend jTracert.

As far as Eclipse projects themselves are concerned, the Eclipse UML2 Tools project might support reverse engineering, although I've have never seen its use in practice.

The MoDisco (Model Discovery) project Eclipse GMT project seems to be clearer in achieving your objective. The list of technology specific tools would be a good place to start with.

You could also give the netbeans UML modeller a try. I have used it to generate javacode that I used in my eclipse projects. You can even import eclipse projects in netbeans and keep the eclipse settings synced with the netbeans project settings.

I tried several UML modellers for eclipse and wasn't satisfied with them. They were either unstable, complicated or just plain ugly. ;-)

You can use the 30 days evaluation build of EclipseUML for Eclipse 3.5 : http://www.uml2.org/eclipse-java-galileo-SR2-win32_eclipseUML2.2_package_may2010.zip This is not the latest 3.6 build, but is pretty good and don't require you purchase it for testing and reverse engineering.

Reverse engineering : http://www.forum-omondo.com/documentation_eclipseuml_2008/reverse/reverse/reverse_engineering_example.html

Live flash demo: http://www.ejb3.org/reverse.swf

EclipseUML Omondo is the best tool in the world for Java. Only eUML seems to compete with it on this live java synchronization market, but eUML adds model tags in the code which is really very very bad and a definitive no go for me.

By far the best tool I have used for reverse engineering, and round tripping java -> UML is Borland's Together. It is based on Eclipse (not just a single plugin) and really works well.

I've noticed SequenceDiagram plugin for Intellij is also a good option.

Another modelling tool for Java is (my) website GitUML. Generate UML diagrams from Java or Python code stored in GitHub repositories.

One key idea with GitUML is to address one of the problems with "documentation": that diagrams are always out of date. With GitUML, diagrams automatically update when you push code using git.

Browse through community UML diagrams, there are some Java design patterns there. Surf through popular GitHub repositories and visualise the architectures and patterns in them.

Create diagrams using point and click. There is no drag drop editor, just click on the classes in the repository tree that you want to visualise:

The underlying technology is PlantUML based, which means you can refine your diagrams with additional PlantUML markup.

There is a Free tool named binarydoc which can generate UML Sequence Diagram, or Control Flow Graph (CFG) from the bytecode (instead of source code) of a Java method.

Here is an sample diagram binarydoc generated for the java method java.net.AbstractPlainSocketImpl.getInputStream:

• Control Flow Graph of method java.net.AbstractPlainSocketImpl.getInputStream:

• UML Sequence Diagram of method java.net.AbstractPlainSocketImpl.getInputStream: