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)