title: How to get failure trace with Junit4
body: <p>in my Junit test, I use usually "AssertEquals" and when the test fails, the trace is properly displayed in the Failure trace of JUnit/eclipse
  I would like to know how to get these trace to show it in a file?</p>
  
  <pre><code>@Test 
    public void testButtons() { 
         SelectionButton().ButtonFile();
         assertEquals("selected button should be edit",FILE.EDIT,File.getSelectedItem);
    } 
  </code></pre>
  
  <p>how could I print/redirect the assert failure trace in a file ?
  thanks</p>