Difference between running a java application as jar or via batch file?Hi,

Question

Hi,
I'm facing some strange differences in the behavior of my application , only caused by different methods to execute the application . So I have know the potential difference between these methods to locate the error.
1) running my application it with java -jar (via batch-file or command-prompt) or in eclipse works fine
2) executing the jar by double click causes problems.
The difference I know are that you can easily pass arguments to jvm, when using the jar.Maybe there is a differences in thread scheduling, but I'm not sure about that.
Can anyone tell me, the differences between these to methods of execution?
Thanks a lot in advance.
Greetings Michael

Answer 1

Hi,
to get a clue I have redirected the System.err and System.out to a TextArea
(see code below) and suddenly the error was gone. So according to the behavior that it had worked before in the ide and via batch file where the System stream can do unlimited writing. I think it is obvious, that something goes wrong with streams of System.
Does anyone knows what happens to messages which are send to the default streams, when running the app as jar? I normally would assume that they would point to /dev/null or something else, but as I have experienced it seems that they are blocking after a certain amount, which prevented my app from working. (By the way invoking it with javaw has the same effect.)
This goes a little bit off topic, perhaps I should post a new thread.
But this is a huge difference between java and and javaw (jar), I wasn't aware of i t until now.
Hope someone can explain me how javaw handles System.err and System.out.
Thanks for your participation.
Greetings Michael
@SuppressWarnings("unused")
     private static void debug(){
          /* Debug Jar-File if no console exists */
          final JTextArea ta = new JTextArea(25, 80);
          ta.setWrapStyleWord(true);
          final JScrollPane jscp = new JScrollPane(ta);     
          class TextAreaPrintStream extends PrintStream {
               private JTextArea consoleTextArea;
               TextAreaPrintStream(JTextArea consoleTextArea, OutputStream out) {
                    super(out);
                    this.consoleTextArea = consoleTextArea;
               /* (non-Javadoc)
                * @see java.io.PrintStream#println(java.lang.String)
               @Override
               public void println(String x) {
                    this.consoleTextArea.append(x +'\n');
               /* (non-Javadoc)
                * @see java.io.PrintStream#print(java.lang.String)
               @Override
               public void print(String s) {
                    this.consoleTextArea.append(s);
          TextAreaPrintStream out = new TextAreaPrintStream(ta, System.out);
          TextAreaPrintStream err = new TextAreaPrintStream(ta, System.err);
          System.setOut(out);
          System.setErr(err);
          JDialog dialog = new JDialog( (Frame) null, "Log" , false);
          dialog.setContentPane(jscp);
          dialog.setSize(dialog.getPreferredSize());
          dialog.setVisible(true);
          System.err.println("Test Error");
     Used proposed solution from sn.schulz :
http://forum.java.sun.com/thread.jspa?forumID=257&threadID=213477