RunTimeException from Thread not logged into SystemErrRule

Question

I am trying test if RunTimeException thrown from thread is added into the System.err. But even after waiting for 1 min it is not found into System.err Following is code piece

public class TestTest {
  @Rule public SystemErrRule errRule = new SystemErrRule().enableLog();

  @org.junit.Test
  public void testLogging(){
    ExecutorRunner.submitTask(new Runnable() {
      @Override public void run() {
        throw new RuntimeException("exception");
      }
    });

Awaitility.await().atMost(60l, TimeUnit.SECONDS).until(new Callable<Boolean>() {
  @Override public Boolean call() throws Exception {
    return errRule.getLog().contains("exception");
  }
});

System.out.println("TestTest.testLogging :: " + "errLog: "+errRule.getLog());
assertTrue(errRule.getLog().contains("exception"));


}

  @After
  public void checkException(){
    System.out.println("TestTest.checkException :: " + "checkin log");
  }

}

class ExecutorRunner{
  static final ExecutorService execService = Executors
    .newCachedThreadPool(new ThreadFactory() {
      AtomicInteger threadNum = new AtomicInteger();

      public Thread newThread(final Runnable r) {
        Thread result = new Thread(r, "Function Execution Thread-"
          + threadNum.incrementAndGet());
        result.setDaemon(true);
        return result;
      }
    });

  static void submitTask(Runnable task) {
    execService.submit(task);
  }
}

Can someone please point out possible mistake in the test?

score 0 · Answer 1 · answered Dec 13 '16 at 15:29

Update your Runnable implementation to

    ExecutorRunner.submitTask(new Runnable() {
        @Override
        public void run() {
            try {
                throw new RuntimeException("exception");
            } catch (RuntimeException e) {
                System.err.print("exception");
            }  
        }
    });

you can also use

System.err.print("exception");

to

 e.printStackTrace();

You should do this like this because SystemErrRule intercepts the writes to System.err. printStackTrace() can do it for you or you can do it manually by using System.err

RunTimeException from Thread not logged into SystemErrRule

1 Answers1