In Java I am using FutureTask to run a Callable asynchronously via Executor. In order to check if an error occurred from the calling thread, I need to throw potential exceptions from the Callable. This however, leads to the stacktrace printed out to System.out (I debugged and this happens inside Unsafe.unpark(Thread) from LockSupport.unpark(Thread)).
Any ideas how I could prevent this?
I already log the exception to a real logger before (via SLF4J) and never want direct stacktraces on System.out.
Update: I think I already pointed out the relevant information but to clarify all the questions: This test case can reproduce the Problem (Method testTransferStreamAsyncCallbackFail()): https://github.com/m-m-m/util/blob/master/io/src/test/java/net/sf/mmm/util/io/base/StreamUtilTest.java
The implementation used is this:
public AsyncTransferrer transferAsync(InputStream inStream, OutputStream outStream, boolean keepOutStreamOpen, TransferCallback callback) { StreamTransferrer transferrer = new StreamTransferrer(inStream, outStream, keepOutStreamOpen, callback); AsyncTransferrerImpl task = new AsyncTransferrerImpl(transferrer); this.executor.execute(task); return task; }
I debugged through the eniter code and it is definetly not my code that logs to the console. This is done in the JDK as I tried to explain.
Additional Update to answer the questions:
The executor I am using is Executors.defaultThreadFactory() As you can see here: https://github.com/m-m-m/util/blob/master/core/src/main/java/net/sf/mmm/util/concurrent/base/SimpleExecutor.java#L30 https://github.com/m-m-m/util/blob/master/io/src/main/java/net/sf/mmm/util/io/base/StreamUtilImpl.java#L165
The output is the stacktrace of the Exception that I throw in my test from the Callable:
java.util.concurrent.ExecutionException: net.sf.mmm.util.io.api.RuntimeIoException: IO: An unexpetected error has occurred while copying data! 23355443-dae9-4f4e-87a2-fe38b8a3d513 at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:192) at net.sf.mmm.util.io.base.StreamUtilImpl$AsyncTransferrerImpl.get(StreamUtilImpl.java:1) at net.sf.mmm.util.io.base.StreamUtilTest.testTransferStreamAsyncCallbackFail(StreamUtilTest.java:171) 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:498) 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.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$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) Caused by: net.sf.mmm.util.io.api.RuntimeIoException: IO: An unexpetected error has occurred while copying data! 23355443-dae9-4f4e-87a2-fe38b8a3d513 at net.sf.mmm.util.io.base.StreamUtilImpl$BaseTransferrer.transfer(StreamUtilImpl.java:533) at net.sf.mmm.util.io.base.StreamUtilImpl$BaseTransferrer.call(StreamUtilImpl.java:583) at net.sf.mmm.util.io.base.StreamUtilImpl$BaseTransferrer.call(StreamUtilImpl.java:1) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.lang.Thread.run(Thread.java:745) Caused by: java.io.IOException: This is a test! at net.sf.mmm.util.io.base.StreamUtilTest.testTransferStreamAsyncCallbackFail(StreamUtilTest.java:155) 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:498) 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.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.runners.ParentRunner.run(ParentRunner.java:363) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)