How do you _really_ get a PrintStream to flush all the time?
- From: "Rob McDonald" <robm@xxxxxxxxxxxxxxxxxxxxxx>
- Date: Thu, 29 Sep 2005 10:04:12 -0400
I create my own PrintStream directed to a JTextArea to act as a console for
a Swing application. I found an example of doing this online & implemented
away...
Unfortunately, writing to the console isn't at all deterministic. Messages
get trimmed. They are printed out of order, linefeeds don't happen.
Generally, it is a mess. And no end of flush() does any good at all...
Any suggestions are appreciated,
Rob
public class Console extends JPanel {
static PrintStream out;
private PipedInputStream piOut;
private PipedOutputStream poOut;
private JTextArea textArea = new JTextArea();
public Console() throws IOException {
piOut = new PipedInputStream();
poOut = new PipedOutputStream(piOut);
out = new PrintStream(poOut, true);
textArea.setEditable(false);
textArea.setRows(10);
textArea.setColumns(80);
add(new JScrollPane(textArea), BorderLayout.CENTER);
setVisible(true);
new ReaderThread(piOut).start();
}
class ReaderThread extends Thread {
PipedInputStream pi;
ReaderThread(PipedInputStream pi) {
this.pi = pi;
}
public void run() {
final byte[] buf = new byte[1024];
try {
while (true) {
final int len = pi.read(buf);
if (len == -1) {
break;
}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
textArea.append(new String(buf, 0, len));
// Make sure the last line is always visible
textArea.setCaretPosition(textArea.getDocument().getLength());
// Keep the text area down to a certain character size
int idealSize = 10000;
int maxExcess = 5000;
int excess = textArea.getDocument().getLength() - idealSize;
if (excess >= maxExcess) {
textArea.replaceRange("", 0, excess);
}
}
});
}
} catch (IOException e) {
}
}
}
}
.
- Follow-Ups:
- Re: How do you _really_ get a PrintStream to flush all the time?
- From: Roedy Green
- Re: How do you _really_ get a PrintStream to flush all the time?
- From: Rob McDonald
- Re: How do you _really_ get a PrintStream to flush all the time?
- Prev by Date: Re: Artificial Intelligence
- Next by Date: Collection
- Previous by thread: Why no SSCCEs?
- Next by thread: Re: How do you _really_ get a PrintStream to flush all the time?
- Index(es):
Relevant Pages
|
|
