IntelliJ IDEA: ClassNotFoundException if run Debug, execution/run does work

Question

I have a Java Maven Project started in Eclipse, worked on it a few days, then imported it in IntelliJ IDEA, again working on it a few days.

The normal Run/Execution in IDEA and via shell does work, but not the Debug.

When I click the Bug Icon for Debug, it opens up URLClassLoader.java file and points on the Line "throw new ClassNotFoundException(name)" and pauses the Debug, if I click Resume Debug, it shows several Classes that do not belong to my project. I can click the Resume Button endless, it shows the same classes, also ClassNotFoundException over and over again in a continuously loop and does not debug my source.

If I click Build -> Rebuild Project it says at the Debug icon "Hot Swap failed myClassname: schema change not implemented; myClassname: Operation not supported by VM"

In the Debug window under Variables it says: "Frame is not available"

The Debug of this project in IntelliJ IDEA did work previously, whats wrong now?

score 61 · Accepted Answer · answered Jan 07 '15 at 20:55

61

Looks like you have an exception breakpoint on ClassNotFoundException. Please try to open Run | View Breakpoints... and uncheck the breakpoint under "Java Exception Breakpoints".

answered Jan 07 '15 at 20:55

yole

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Thanks! It works. I can now debug my program. But why is there a ClassNotFoundException? – Marco Wagner Jan 08 '15 at 09:48
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It's a normal part of a Java program initialization. – yole Jan 08 '15 at 21:01
Thanks a lot, I was forced to remember how to use remote debug - same as I did in 2011-12 :) – Alex Barkun Mar 16 '17 at 09:56
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how is that normal ? – TheBakker Nov 08 '17 at 10:49
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Anyone know how the all exceptions breakpoint would suddenly get turned on without being noticed. – Lee Meador Nov 22 '19 at 18:58

score 0 · Answer 2 · answered Jan 16 '19 at 06:27

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This is really helpful. Go to your breakpoints in debug mode and make sure to deselect all the breakpoints first and then select only the ones in your class.

answered Jan 16 '19 at 06:27

Charu Khatwani

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score 0 · Answer 3 · answered Aug 23 '19 at 16:28

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in my situation, just neglect the evaluate language drop down.

answered Aug 23 '19 at 16:28

SalutonMondo

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IntelliJ IDEA: ClassNotFoundException if run Debug, execution/run does work

3 Answers3

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