To put breakpoints in your code, double click in the left margin on the line you want execution to stop on. You may alternatively put your cursor in this line and then press Shift+Ctrl+B.
To control execution use the Step Into, Step Over and Step Return buttons. They have the shortcuts F5, F6 and F7 respectively.
To allow execution to continue normally or until it hits the next breakpoint, hit the Resume button or F8.
Answer from James on Stack OverflowTo put breakpoints in your code, double click in the left margin on the line you want execution to stop on. You may alternatively put your cursor in this line and then press Shift+Ctrl+B.
To control execution use the Step Into, Step Over and Step Return buttons. They have the shortcuts F5, F6 and F7 respectively.
To allow execution to continue normally or until it hits the next breakpoint, hit the Resume button or F8.
Here is a video about Debugging with eclipse.
For more details read this page.
Instead of Debugging as Java program, use Debug as Android Application
May help new comers.
Videos
You can easily set method breakpoints in 3rd party libraries without having the source. Just open the class (you'll get the "i-have-no-source" view). Open the outline, right-click on the method you want and click on Toggle Method Breakpoint to create the method breakpoint.
The most sure-fire way to do this (and end up with something that's actually useful) is to download the source (you say that it is open-source), and set up another "Java Project" pointing at that source.
To do that, get the source downloaded and unzipped somewhere on your system. Click "File"->"New"->"Java Project". In the next dialog, give it a project name and select "Create Project from Existing Source". Browse to the root location of the open source library.
Supposing that all the additional libraries that are required by the project and such are included in the project you downloaded, Eclipse will figure everything out and set the build path up for you.
You'll need to remove the open source jar from your project's build path, and add this new project to the build path of your project.
Now, you can just treat this as your code, and debug at will.
This gets around at least a couple of problems with other approaches:
You could "attach source" to the jar file, but if the jar file was compiled without debug information, this still won't work. If the jar file was compiled with debug information (
lines,source,vars...see http://java.sun.com/j2se/1.3/docs/tooldocs/win32/javac.html, and the-goption).You could add an "exception breakpoint" to see when the NullPointerException is raised, but that's a common exception, and may well get raised and dealt with many (hundreds of?) times prior to the one you're looking for. Plus, without the original source, you won't be able to really see much of anything about the code that is throwing the NullPointerException - the likelihood you'll be able to figure out what's wrong is pretty low.
You've probably just pressed "Skip All Breakpoints" in the Breakpoint view - simply press it again.
Default key bindings are: Ctrl + Alt + B.
This doesn't exactly answer the OPs question, but when trying to double click to add break points, I was getting messages stating "this feature is not enabled".
I had to right click on the break point bar and select "Breakpoint Types" -> "C/C++ Breakpoints" instead of "Default". Then it worked fine.