Java HeadlessException?

问题

I'm trying to do unit test to my java GUI source code in Eclipse.

When I execute unit test with jUnit, all of my test succeed.

However, I encountered a small exception in SonarQube report as well as my tests which was successful in eclipse are reported all failed.

Exception messages are here.

No X11 DISPLAY variable was set, but this program performed an operation which requires it.
java.awt.HeadlessException: 
  No X11 DISPLAY variable was set, but this program performed an operation which requires it.
    at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207)
    at java.awt.Window.<init>(Window.java:536)
    at java.awt.Frame.<init>(Frame.java:420)
    at javax.swing.JFrame.<init>(JFrame.java:233)
    at com.kaist.se.pmpdaemon.MainFrame.<init>(MainFrame.java:56)
    at com.kaist.se.pmpdaemon.MainFrameTest.testSetMainText(MainFrameTest.java:80)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:53)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:123)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:104)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:164)
    at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:110)
    at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:175)
    at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcessWhenForked(SurefireStarter.java:107)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:68)

What should I do?

回答1:

You have to move your Sonar/test server to the same environment where it will run eventually - Windows in your case. See, AWT uses platform GUI environment. So, it takes graphical parts from the system. In other words - Label on Windows looks different then on Mac and different on Unix. In last case Unix may have no Graphical environment at all and so you will have no Label too. Headless allows you compile and run "graphical" environment without platform support.

回答2:

I installed xvnc plugin in jenkins, and vnc4server in my server.

then it is completely solved.

reference : https://developer.cloudbees.com/bin/view/DEV/Testing+GUI+applications http://blog.dahanne.net/2011/07/18/run-ui-tests-on-a-headless-jenkins-hudson-continuous-integration-server-running-ubuntu/

来源：https://stackoverflow.com/questions/30640902/java-headlessexception