Java tutorial
/* * IzPack - Copyright 2001-2008 Julien Ponge, All Rights Reserved. * * http://izpack.org/ * http://izpack.codehaus.org/ * * Copyright 2002 Jan Blok * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import javax.swing.*; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; import javax.swing.text.Document; import javax.swing.text.Segment; import java.awt.*; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import java.io.*; import java.util.Vector; public final class Console { public static final int INITIAL_WIDTH = 800; public static final int INITIAL_HEIGHT = 600; public static void main(String[] args) { Runtime rt = Runtime.getRuntime(); Process p = null; try { /* * Start a new process in which to execute the commands in cmd, using the environment in * env and use pwd as the current working directory. */ p = rt.exec(args);// , env, pwd); new Console(p); System.exit(p.exitValue()); } catch (IOException e) { /* * Couldn't even get the command to start. Most likely it couldn't be found because of a * typo. */ System.out.println("Error starting: " + args[0]); System.out.println(e); } } private StdOut so; private StdOut se; public String getOutputData() { if (so != null) { return so.getData(); } else { return ""; } } public String getErrorData() { if (se != null) { return se.getData(); } else { return ""; } } public Console(Process p) { JFrame frame = new JFrame(); frame.setTitle("Console"); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); frame.setLocation(screenSize.width / 2 - INITIAL_WIDTH / 2, screenSize.height / 2 - INITIAL_HEIGHT / 2); ConsoleTextArea cta = new ConsoleTextArea(); JScrollPane scroll = new JScrollPane(cta); scroll.setPreferredSize(new Dimension(INITIAL_WIDTH, INITIAL_HEIGHT)); frame.getContentPane().add(scroll); frame.pack(); // From here down your shell should be pretty much // as it is written here! /* * Start up StdOut, StdIn and StdErr threads that write the output generated by the process * p to the screen, and feed the keyboard input into p. */ so = new StdOut(p, cta); se = new StdOut(p, cta); StdIn si = new StdIn(p, cta); so.start(); se.start(); si.start(); // Wait for the process p to complete. try { frame.setVisible(true); p.waitFor(); } catch (InterruptedException e) { /* * Something bad happened while the command was executing. */ System.out.println("Error during execution"); System.out.println(e); } /* * Now signal the StdOut, StdErr and StdIn threads that the process is done, and wait for * them to complete. */ try { so.done(); se.done(); si.done(); so.join(); se.join(); si.join(); } catch (InterruptedException e) { // Something bad happend to one of the Std threads. System.out.println("Error in StdOut, StdErr or StdIn."); System.out.println(e); } frame.setVisible(false); } } class StdIn extends Thread { private BufferedReader kb; private boolean processRunning; private PrintWriter op; public StdIn(Process p, ConsoleTextArea cta) { setDaemon(true); InputStreamReader ir = new InputStreamReader(cta.getIn()); kb = new BufferedReader(ir); BufferedOutputStream os = new BufferedOutputStream(p.getOutputStream()); op = new PrintWriter((new OutputStreamWriter(os)), true); processRunning = true; } public void run() { try { while (kb.ready() || processRunning) { if (kb.ready()) { op.println(kb.readLine()); } } } catch (IOException e) { System.err.println("Problem reading standard input."); System.err.println(e); } } public void done() { processRunning = false; } } class StdOut extends Thread { private InputStreamReader output; private boolean processRunning; private ConsoleTextArea cta; private StringBuffer data; public StdOut(Process p, ConsoleTextArea cta) { setDaemon(true); output = new InputStreamReader(p.getInputStream()); this.cta = cta; processRunning = true; data = new StringBuffer(); } public void run() { try { /* * Loop as long as there is output from the process to be displayed or as long as the * process is still running even if there is presently no output. */ while (output.ready() || processRunning) { // If there is output get it and display it. if (output.ready()) { char[] array = new char[255]; int num = output.read(array); if (num != -1) { String s = new String(array, 0, num); data.append(s); SwingUtilities.invokeAndWait(new ConsoleWrite(cta, s)); } } } } catch (Exception e) { System.err.println("Problem writing to standard output."); System.err.println(e); } } public void done() { processRunning = false; } public String getData() { return data.toString(); } } class ConsoleWrite implements Runnable { private ConsoleTextArea textArea; private String str; public ConsoleWrite(ConsoleTextArea textArea, String str) { this.textArea = textArea; this.str = str; } public void run() { textArea.write(str); } } class ConsoleWriter extends java.io.OutputStream { private ConsoleTextArea textArea; private StringBuffer buffer; public ConsoleWriter(ConsoleTextArea textArea) { this.textArea = textArea; buffer = new StringBuffer(); } public synchronized void write(int ch) { buffer.append((char) ch); if (ch == '\n') { flushBuffer(); } } public synchronized void write(char[] data, int off, int len) { for (int i = off; i < len; i++) { buffer.append(data[i]); if (data[i] == '\n') { flushBuffer(); } } } public synchronized void flush() { if (buffer.length() > 0) { flushBuffer(); } } public void close() { flush(); } private void flushBuffer() { String str = buffer.toString(); buffer.setLength(0); SwingUtilities.invokeLater(new ConsoleWrite(textArea, str)); } } class ConsoleTextArea extends JTextArea implements KeyListener, DocumentListener { /** * */ private static final long serialVersionUID = 3258410625414475827L; private ConsoleWriter console1; private PrintStream out; private PrintStream err; private PrintWriter inPipe; private PipedInputStream in; private Vector<String> history; private int historyIndex = -1; private int outputMark = 0; public void select(int start, int end) { requestFocus(); super.select(start, end); } public ConsoleTextArea() { super(); history = new java.util.Vector<String>(); console1 = new ConsoleWriter(this); ConsoleWriter console2 = new ConsoleWriter(this); out = new PrintStream(console1); err = new PrintStream(console2); PipedOutputStream outPipe = new PipedOutputStream(); inPipe = new PrintWriter(outPipe); in = new PipedInputStream(); try { outPipe.connect(in); } catch (IOException exc) { exc.printStackTrace(); } getDocument().addDocumentListener(this); addKeyListener(this); setLineWrap(true); setFont(new Font("Monospaced", 0, 12)); } void returnPressed() { Document doc = getDocument(); int len = doc.getLength(); Segment segment = new Segment(); try { synchronized (doc) { doc.getText(outputMark, len - outputMark, segment); } } catch (javax.swing.text.BadLocationException ignored) { ignored.printStackTrace(); } if (segment.count > 0) { history.addElement(segment.toString()); } historyIndex = history.size(); inPipe.write(segment.array, segment.offset, segment.count); append("\n"); synchronized (doc) { outputMark = doc.getLength(); } inPipe.write("\n"); inPipe.flush(); console1.flush(); } public void eval(String str) { inPipe.write(str); inPipe.write("\n"); inPipe.flush(); console1.flush(); } public void keyPressed(KeyEvent e) { int code = e.getKeyCode(); if (code == KeyEvent.VK_BACK_SPACE || code == KeyEvent.VK_LEFT) { if (outputMark == getCaretPosition()) { e.consume(); } } else if (code == KeyEvent.VK_HOME) { int caretPos = getCaretPosition(); if (caretPos == outputMark) { e.consume(); } else if (caretPos > outputMark) { if (!e.isControlDown()) { if (e.isShiftDown()) { moveCaretPosition(outputMark); } else { setCaretPosition(outputMark); } e.consume(); } } } else if (code == KeyEvent.VK_ENTER) { returnPressed(); e.consume(); } else if (code == KeyEvent.VK_UP) { historyIndex--; if (historyIndex >= 0) { if (historyIndex >= history.size()) { historyIndex = history.size() - 1; } if (historyIndex >= 0) { String str = history.elementAt(historyIndex); int len = getDocument().getLength(); replaceRange(str, outputMark, len); int caretPos = outputMark + str.length(); select(caretPos, caretPos); } else { historyIndex++; } } else { historyIndex++; } e.consume(); } else if (code == KeyEvent.VK_DOWN) { int caretPos = outputMark; if (history.size() > 0) { historyIndex++; if (historyIndex < 0) { historyIndex = 0; } int len = getDocument().getLength(); if (historyIndex < history.size()) { String str = history.elementAt(historyIndex); replaceRange(str, outputMark, len); caretPos = outputMark + str.length(); } else { historyIndex = history.size(); replaceRange("", outputMark, len); } } select(caretPos, caretPos); e.consume(); } } public void keyTyped(KeyEvent e) { int keyChar = e.getKeyChar(); if (keyChar == 0x8 /* KeyEvent.VK_BACK_SPACE */) { if (outputMark == getCaretPosition()) { e.consume(); } } else if (getCaretPosition() < outputMark) { setCaretPosition(outputMark); } } public void keyReleased(KeyEvent e) { } public synchronized void write(String str) { insert(str, outputMark); int len = str.length(); outputMark += len; select(outputMark, outputMark); } public synchronized void insertUpdate(DocumentEvent e) { int len = e.getLength(); int off = e.getOffset(); if (outputMark > off) { outputMark += len; } } public synchronized void removeUpdate(DocumentEvent e) { int len = e.getLength(); int off = e.getOffset(); if (outputMark > off) { if (outputMark >= off + len) { outputMark -= len; } else { outputMark = off; } } } public void postUpdateUI() { // this attempts to cleanup the damage done by updateComponentTreeUI requestFocus(); setCaret(getCaret()); synchronized (this) { select(outputMark, outputMark); } } public void changedUpdate(DocumentEvent e) { } public InputStream getIn() { return in; } public PrintStream getOut() { return out; } public PrintStream getErr() { return err; } }