Synchronize System.out & System.err

Question

When debugging code I tend to use System.out & System.err quite a lot. The problem is when an exception is ocurring and i use System.out the same time the outcome doesn't look very organized.

[CLIENT]:postinit: vic.rpg.gui.GuiMain.init()
java.net.ConnectException: Connection refused: connect
[CLIENT]:Destroying Network Thread...
[CLIENT]:done!
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
...
[CLIENT]:Starting Server...

It's not very severe but it makes reading logs a little bit difficult sometimes.

You would not have that sort of issues if you used a proper logging framework. — assylias, Feb 10 '14 at 10:49

Tony the Pony · Accepted Answer · 2014-02-10T10:58:33.437

1

You can avoid this issue by calling flush each time you write to either stream. e.g.:

System.out.println ("Writing to *out*");
System.out.flush ();

If you are logging from different threads, then your logging messages will naturally interleave. If you want to cleanly separate the output by threads, I'd suggest using a logging library such as log4j.

edited Feb 10 '14 at 10:58

answered Feb 10 '14 at 10:49

Tony the Pony

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I was already wrapping System.out into my own PrintStream, adding a `super.flush()` to every method did work. – Vic Feb 10 '14 at 10:55

Synchronize System.out & System.err

1 Answers1