[EXEC-32] PumpStreamHandler handles null streams inconsistently

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0
• Assignee: Siegfried Goeschl
• Reporter: Marco Ferrante
• Created: 30/Dec/08 16:29
• Updated: 24/Oct/10 19:58
• Resolved: 01/Feb/09 21:19

Description

Passing null arguments in PumpStreamHandler constructors produces hard-to-understand errors.

E.g.

  PumpStreamHandler streamHanlder = new PumpStreamHandler(System.out, System.err, null);

works correctly, so you can expect that null is a valid argument.

Instead

  PumpStreamHandler streamHanlder = new PumpStreamHandler(System.out, null, null);

raise a NullPointerException when Executor.execute() is invoked.
Note that exception is raised by the start() method of PumpStreamHandler .

Surprisingly

  PumpStreamHandler streamHanlder = new PumpStreamHandler(null, System.err, null);

starts correctly, but fails with a NullPointerException when the process exits.
In this case, the exception is raised by the stop() method of PumpStreamHandler .

I think that the behavior should be more consistent and, if necessary, errors must be reported earlier.
So I suggest two alternatives:

• if a null argument is passed to a constructor as stdout/stderr an exception is raised immediately
• or, if stdout or stderr are set to null, default System.out and System.err are used instead.
  At least, the error should be reported before starting process in every case.