Re: Turning a JTextArea into a InputStream

From:
Daniele Futtorovic <da.futt.news@laposte.invalid>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 01 Jul 2008 11:46:44 +0200
Message-ID:
<g4cu7t$kqn$1@registered.motzarella.org>
On 2008-07-01 11:33 +0100, cokofreedom@gmail.com allegedly wrote:

I've been trying to convert a JTextArea into an InputStream with
almost no success. After trying to google for a few results any that I
have found have been of little use.

The idea is to use the JSch to SSH using a JTextArea as an Input and
another as an Output (with the possibility in the future of linking
them together). I have been able to make the Output work with the
following coe segments:

PrintStream out = new PrintStream(new
TextAreaOutputStream(txtOutput));

    final class TextAreaOutputStream extends OutputStream {
        private final JTextArea textArea;
        private final StringBuilder sb = new StringBuilder();
        public TextAreaOutputStream(final JTextArea textArea) {
        this.textArea = textArea;
        }
        @Override
        public void write(int b) throws IOException {
            if (b == '\r') { return; }
            if (b == '\n') {
                textArea.append(sb.toString());
                sb.setLength(0);
            }
            sb.append((char)b);
        }
    }

However my attempts with something similar for an InputStream have
been largely unsuccessful. Based upon a forum entry on the
java.sun.com forum I tried to implement the following:

    final class TextAreaInputStream extends InputStream implements
KeyListener {
        String lastLine;
        int lastKeyCode;
        JTextArea txtInput;
        Object mKeyLock = new Object();
        Object mLineLock = new Object();
        private TextAreaInputStream(JTextArea txtInput) {
            this.txtInput = txtInput;
        }
        public String readLine() {
            synchronized(mLineLock) {
                try {
                    mLineLock.wait();
                } catch (InterruptedException ex) {
                    System.err.println(ex.getMessage());
                }
            }
            return lastLine;
        }
        @Override
        public int read() {
            synchronized(mKeyLock) {
                try {
                    mKeyLock.wait();
                } catch (InterruptedException ex) {
                    System.err.println(ex.getMessage());
                }
            }
            return lastKeyCode;
        }
        public void keyReleased(KeyEvent e) { }
        public void keyTyped(KeyEvent e) { }
        public void keyPressed(KeyEvent e) {
            System.err.println("keyPressed");
            lastKeyCode = e.getKeyCode();
            if (lastKeyCode == KeyEvent.VK_ENTER) {
                String txt = txtInput.getText();
                int idx = txt.lastIndexOf(
                        \n', txtInput.getCaretPosition() - 1);
                lastLine = txt.substring(
                        idx != -1 ? idx : 0,
txtInput.getCaretPosition());
            }
        }
        public InputStream toInputStream() {
            return new MyInputStream();
        }
        private class MyInputStream extends InputStream {
            public int read() {
                return TextAreaInputStream.this.read();
            }
        }
    }

However I do not think this does anything...So I really just want to
be able to send commands from a JTextArea through the SSH and get the
reply, and presently I can only get the Reply if I use System.in...

If someone can guide me to a step I have missed, or perhaps get me
back on track that would be of great help to me!

Thanks

Coko


- Add a few listeners to the TextArea's underlying Document model to
track text input. Write text additions to a simple ByteArrayOutputStream.
- Use Piped(Output|Input)Streams (wrap the BAOUS into a POS, connect
that pipe to a PIS, voil?).

Note: your approach is a bit flawed inasmuch as you won't be able to
deal with text deletions and additions elsewhere than at the end.

--
DF.
to reply privately, change the top-level domain
in the FROM address from "invalid" to "net"

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