/* * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * *   - Redistributions of source code must retain the above copyright *     notice, this list of conditions and the following disclaimer. * *   - Redistributions in binary form must reproduce the above copyright *     notice, this list of conditions and the following disclaimer in the *     documentation and/or other materials provided with the distribution. * *   - Neither the name of Sun Microsystems nor the names of its *     contributors may be used to endorse or promote products derived *     from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Java(TM) SE 6 version. * SwingWorker can be downloaded at: * https://swingworker.dev.java.net/ * SwingWorker is included in Java(TM) SE 6. */import javax.swing.*;import java.awt.*;import java.awt.event.*;import java.io.*;import java.net.*;import java.util.*;public class QuoteClientApplet extends JApplet                                implements ActionListener {    private static boolean DEBUG = false;    private InetAddress address;    private JTextField portField;    private JLabel display;    private JButton sendButton;    private JProgressBar progressBar;    private DatagramSocket socket;    private String host;    private static final int MAX_NUM_CHARS = 256;    private static final int TIMEOUT = 500; //time out after 1/2 a second    private static String sendButtonText = "OK";    private QuoteGetter quoteGetter;    public void init() {        //Initialize networking stuff.        host = getCodeBase().getHost();        try {            address = InetAddress.getByName(host);        } catch (UnknownHostException e) {            System.err.println("Couldn't get Internet address: Unknown host");            // What should we do?        }        try {            socket = new DatagramSocket();            socket.setSoTimeout(TIMEOUT);        } catch (IOException e) {            System.err.println("Couldn't create new DatagramSocket");            return;        }        //Set up the UI.        //Execute a job on the event-dispatching thread:        //creating this applet's GUI.        try {            SwingUtilities.invokeAndWait(new Runnable() {                public void run() {                    createGUI();                }            });        } catch (Exception e) {            System.err.println("createGUI didn't successfully complete");        }    }    private void createGUI() {        JPanel contentPane = new JPanel(new GridBagLayout());        GridBagConstraints c = new GridBagConstraints();        int numColumns = 3;        JLabel l1 = new JLabel("Quote of the Moment:", JLabel.CENTER);        c.gridx = 0;        c.gridy = 0;        c.anchor = GridBagConstraints.SOUTH;        c.gridwidth = numColumns;        contentPane.add(l1, c);        display = new JLabel("(no quote received yet)", JLabel.CENTER);        display.setForeground(Color.gray);        c.gridy = 1;        c.gridwidth = numColumns;        c.anchor = GridBagConstraints.CENTER;        c.weighty = 1.0;        c.fill = GridBagConstraints.HORIZONTAL;        contentPane.add(display, c);        JLabel l2 = new JLabel("Enter the port (on host " + host                               + ") to send the request to:",                                JLabel.RIGHT);        c.gridy = 2;        c.gridwidth = 1;        c.anchor = GridBagConstraints.SOUTH;        c.weighty = 0.0;        c.fill = GridBagConstraints.NONE;        contentPane.add(l2, c);        portField = new JTextField(6);        c.gridx = 1;        c.weightx = 1.0;        c.insets = new Insets(0,5,0,0);        c.fill = GridBagConstraints.HORIZONTAL;        contentPane.add(portField, c);        sendButton = new JButton(sendButtonText);        c.gridx = 2;        c.weightx = 0.0;        c.fill = GridBagConstraints.NONE;        contentPane.add(sendButton, c);                progressBar = new JProgressBar();        c.gridx = 0;        c.gridy = 3;        c.gridwidth = numColumns;        c.fill = GridBagConstraints.HORIZONTAL;        c.insets = new Insets(5,0,5,0);        contentPane.add(progressBar, c);                portField.addActionListener(this);        sendButton.addActionListener(this);                //Finish setting up the content pane and its border.        contentPane.setBorder(BorderFactory.createCompoundBorder(                                    BorderFactory.createLineBorder(Color.black),                                    BorderFactory.createEmptyBorder(5,20,5,10)));        setContentPane(contentPane);    }    private class QuoteGetter extends               org.jdesktop.swingworker.SwingWorker<String, String> {        int port;        InetAddress address;                public QuoteGetter(int port, InetAddress address) {            this.port = port;            this.address = address;        }         @Override         public String doInBackground() {            DatagramPacket packet;            byte[] sendBuf = new byte[MAX_NUM_CHARS];            packet = new DatagramPacket(sendBuf, MAX_NUM_CHARS, address, port);            try { // send request                if (DEBUG) {                    System.out.println("Applet about to send packet to address "                                   + address + " at port " + port);                }                socket.send(packet);                if (DEBUG) {                    System.out.println("Applet sent packet.");                }            } catch (IOException e) {                System.err.println("Applet socket.send failed:\n"                                   + e.getStackTrace());                return null;            }            packet = new DatagramPacket(sendBuf, MAX_NUM_CHARS);            try { // get response                if (DEBUG) {                    System.out.println("Applet about to call socket.receive().");                }                socket.receive(packet);                if (DEBUG) {                    System.out.println("Applet returned from socket.receive().");                }            } catch (SocketTimeoutException e) {                System.err.println("Applet socket.receive timed out.");                //Should let the user know in the UI.s                return null;            } catch (IOException e) {                System.err.println("Applet socket.receive failed:\n"                                   + e.getStackTrace());                return null;            }            String received = new String(packet.getData());            StringBuffer data = new StringBuffer(received);            //Hack alert! Assuming the last character is garbage, rid            //this string of all garbage characters.            int firstGarbage = data.indexOf(Character.toString(                                            received.charAt(MAX_NUM_CHARS - 1)));            if (firstGarbage > -1) {                data.delete(firstGarbage, MAX_NUM_CHARS);            }            return data.toString();         }                 //Once the socket has been read, display what it sent.        protected void done() {            if (DEBUG) {                System.out.println("SwingWorker is done.");            }            progressBar.setIndeterminate(false);                        try {                 String s = get();                if (DEBUG) {                    System.out.println("get() returned \"" + s + "\"");                }                if (s != null) {                                        //Display the text.                    display.setForeground(Color.gray);                    display.setText(s);                } else {                    display.setForeground(Color.red);                    display.setText("Read failed (see console for details).");                }            } catch (Exception ignore) { }         }    }        //invoked on the event-dispatching thread    private void doIt(int port) {        //Listen to the port on a background thread to avoid        //tying up the GUI.        quoteGetter = new QuoteGetter(port, address);        quoteGetter.execute();                display.setForeground(Color.gray);        display.setText("Reading port #" + port);    }    public void actionPerformed(ActionEvent event) {        try {            int port = Integer.parseInt(portField.getText());            progressBar.setIndeterminate(true);            doIt(port);        } catch (NumberFormatException e) {            //No integer entered.            display.setForeground(Color.red);            display.setText("Please enter a number in the text field below.");        }    }        public void destroy() {        //destroy the DatagramSocket?        if (socket != null) {            socket.close();        }        //Set up the UI.        //Execute a job on the event-dispatching thread:        //creating this applet's GUI.        try {            SwingUtilities.invokeAndWait(new Runnable() {                public void run() {                    getContentPane().removeAll();                }            });        } catch (Exception e) { }    }}