Eclipse cannot enter debug mode workaround

I use spring source development tools, yesterday afternoon originally wanted to debug the program, found unable to enter the debug mode, set a breakpoint is not used, directly return to the non-debug mode of the results of the run, found on the internet for half a day did not find a solution.

There are several ways to provide this online:

1, check the location of the breakpoint settings is correct, you can add a breakpoint at the SYSTEM.OUT.PRINTLN () statement, see Run the program after the output.

2. Check whether the service starts normally.

3, clean under the project and then recompile run.

I have tried all these methods and have no effect. I deleted the project to re-import, or not. Later, under the guidance of colleagues, only solved the problem.
Specific methods:

Locate the item in debug, right click, select Edit Source Lookup, remove the previous, then add current workspace. Finally confirm, restart the service is ready.

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If you have entered the debug mode, but the program does not have a green progress bar tracking, so do, also OK.