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Related questions

(Unknown Source) in Exception stack trace

Unknown Source in Stacktrace Java Eclipse

My case

I'm compiling a project using maven 3.1.0. Then it is deployed on Tomcat 7 On my stacktrace, I get (Unknown Source) instead of (myclass.java:14). It happens with my classes but works normally with others libraries.

From the related topics, I learn that it is due to missing line number in the class files. It may be due because the use of a jre or a wrong configuration. Here is some step I have tried:

  • I recently moved from jdk 1.6 to jdk1.7.0_21 (which looks to be the cause of the problem). I tried with three java installations (jdk1.7.0_21, 32 & 64bits and jdk1.7.0_45). JAVA_HOME is pointing to the right folder.

  • I see that we can add debug and debuglevel option to javac. I tried to add them to maven with the following configuration. I also force to use javac instead of javax.

        <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
            <source>${jdk.version}</source>
            <target>${jdk.version}</target>
            <debuglevel>lines,vars,source</debuglevel>
            <debug>true</debug>
            <forceJavacCompilerUse>true</forceJavacCompilerUse>
        </configuration>
    </plugin>
  • Erase target file and tomcat war.

Nothing works...

EDIT Using javap -l on the class shows the LineNumberTable:

public void init();
  LineNumberTable:
    line 31: 0
    line 32: 10
    line 33: 21
    ...

The problem comes most likely from the tomcat7 side.

Community
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Nereis
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  • You can try checking the compiled `.class` files using `javap`. Although unlikely, it may be possible that the lines are there but Tomcat does something shifty while loading them. You can also create a completely new project with a single test java file and your compiler options in the POM, just to help you simplify the task. – biziclop Dec 03 '13 at 08:29
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    Run `mvn -X compile` to see what is maven actually doing. Run `mvn help:effective-pom` to see the final maven configuration. – Grzegorz Żur Dec 03 '13 at 08:31
  • @biziclop Ok that strange `javap -l` shows the LineNumberTable. I will look in the tomcat side – Nereis Dec 03 '13 at 09:00
  • It must be some VM optimisation flag or similar in Tomcat then. – biziclop Dec 03 '13 at 09:04
  • Not yet. I didn't find anything interesting on the side of tomcat or VM. I should go for a simple test case but I hadn't the time yet. But I think it's strange that the problem comes from tomcat. – Nereis Dec 09 '13 at 14:40

1 Answers1

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The problem was coming from the JVM.

I use Jensor for profiling my application. It uses Aspect and a javaagent in order to collect data.

By removing the -javaagent:... from the java options solved the problem.

Nereis
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