vncviewer.java

JAVA版vpn客户端,是在web上实现远程访问的最佳方式.

//
//  Copyright (C) 2001-2004 HorizonLive.com, Inc.  All Rights Reserved.
//  Copyright (C) 2002 Constantin Kaplinsky.  All Rights Reserved.
//  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
//
//  This is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This software is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this software; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
//  USA.
//

//
// VncViewer.java - the VNC viewer applet.  This class mainly just sets up the
// user interface, leaving it to the VncCanvas to do the actual rendering of
// a VNC desktop.
//

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

public class VncViewer extends java.applet.Applet
  implements java.lang.Runnable, WindowListener {

  boolean inAnApplet = true;
  boolean inSeparateFrame = false;

  //
  // main() is called when run as a java program from the command line.
  // It simply runs the applet inside a newly-created frame.
  //

  public static void main(String[] argv) {
    VncViewer v = new VncViewer();
    v.mainArgs = argv;
    v.inAnApplet = false;
    v.inSeparateFrame = true;

    v.init();
    v.start();
  }

  String[] mainArgs;

  RfbProto rfb;
  Thread rfbThread;

  Frame vncFrame;
  Container vncContainer;
  ScrollPane desktopScrollPane;
  GridBagLayout gridbag;
  ButtonPanel buttonPanel;
  Label connStatusLabel;
  VncCanvas vc;
  OptionsFrame options;
  ClipboardFrame clipboard;
  RecordingFrame rec;

  // Control session recording.
  Object recordingSync;
  String sessionFileName;
  boolean recordingActive;
  boolean recordingStatusChanged;
  String cursorUpdatesDef;
  String eightBitColorsDef;

  // Variables read from parameter values.
  String socketFactory;
  String host;
  int port;
  String passwordParam;
  boolean showControls;
  boolean offerRelogin;
  boolean showOfflineDesktop;
  int deferScreenUpdates;
  int deferCursorUpdates;
  int deferUpdateRequests;

  // Reference to this applet for inter-applet communication.
  public static java.applet.Applet refApplet;

  //
  // init()
  //

  public void init() {

    readParameters();

    refApplet = this;

    if (inSeparateFrame) {
      vncFrame = new Frame("TightVNC");
      if (!inAnApplet) {
	vncFrame.add("Center", this);
      }
      vncContainer = vncFrame;
    } else {
      vncContainer = this;
    }

    recordingSync = new Object();

    options = new OptionsFrame(this);
    clipboard = new ClipboardFrame(this);
    if (RecordingFrame.checkSecurity())
      rec = new RecordingFrame(this);

    sessionFileName = null;
    recordingActive = false;
    recordingStatusChanged = false;
    cursorUpdatesDef = null;
    eightBitColorsDef = null;

    if (inSeparateFrame)
      vncFrame.addWindowListener(this);

    rfbThread = new Thread(this);
    rfbThread.start();
  }

  public void update(Graphics g) {
  }

  //
  // run() - executed by the rfbThread to deal with the RFB socket.
  //

  public void run() {

    gridbag = new GridBagLayout();
    vncContainer.setLayout(gridbag);

    GridBagConstraints gbc = new GridBagConstraints();
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.anchor = GridBagConstraints.NORTHWEST;

    if (showControls) {
      buttonPanel = new ButtonPanel(this);
      gridbag.setConstraints(buttonPanel, gbc);
      vncContainer.add(buttonPanel);
    }

    try {
      connectAndAuthenticate();
      doProtocolInitialisation();

      // FIXME: Use auto-scaling not only in a separate frame.
      if (options.autoScale && inSeparateFrame) {
	Dimension screenSize;
	try {
	  screenSize = vncContainer.getToolkit().getScreenSize();
	} catch (Exception e) {
	  screenSize = new Dimension(0, 0);
	}
	createCanvas(screenSize.width - 32, screenSize.height - 32);
      } else {
	createCanvas(0, 0);
      }

      gbc.weightx = 1.0;
      gbc.weighty = 1.0;

      if (inSeparateFrame) {

	// Create a panel which itself is resizeable and can hold
	// non-resizeable VncCanvas component at the top left corner.
	Panel canvasPanel = new Panel();
	canvasPanel.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
	canvasPanel.add(vc);

	// Create a ScrollPane which will hold a panel with VncCanvas
	// inside.
	desktopScrollPane = new ScrollPane(ScrollPane.SCROLLBARS_AS_NEEDED);
	gbc.fill = GridBagConstraints.BOTH;
	gridbag.setConstraints(desktopScrollPane, gbc);
	desktopScrollPane.add(canvasPanel);

	// Finally, add our ScrollPane to the Frame window.
	vncFrame.add(desktopScrollPane);
	vncFrame.setTitle(rfb.desktopName);
	vncFrame.pack();
	vc.resizeDesktopFrame();

      } else {

	// Just add the VncCanvas component to the Applet.
	gridbag.setConstraints(vc, gbc);
	add(vc);
	validate();

      }

      if (showControls)
	buttonPanel.enableButtons();

      moveFocusToDesktop();
      processNormalProtocol();

    } catch (NoRouteToHostException e) {
      fatalError("Network error: no route to server: " + host, e);
    } catch (UnknownHostException e) {
      fatalError("Network error: server name unknown: " + host, e);
    } catch (ConnectException e) {
      fatalError("Network error: could not connect to server: " +
		 host + ":" + port, e);
    } catch (EOFException e) {
      if (showOfflineDesktop) {
	e.printStackTrace();
	System.out.println("Network error: remote side closed connection");
	if (vc != null) {
	  vc.enableInput(false);
	}
	if (inSeparateFrame) {
	  vncFrame.setTitle(rfb.desktopName + " [disconnected]");
	}
	if (rfb != null && !rfb.closed())
	  rfb.close();
	if (showControls && buttonPanel != null) {
	  buttonPanel.disableButtonsOnDisconnect();
	  if (inSeparateFrame) {
	    vncFrame.pack();
	  } else {
	    validate();
	  }
	}
      } else {
	fatalError("Network error: remote side closed connection", e);
      }
    } catch (IOException e) {
      String str = e.getMessage();
      if (str != null && str.length() != 0) {
	fatalError("Network Error: " + str, e);
      } else {
	fatalError(e.toString(), e);
      }
    } catch (Exception e) {
      String str = e.getMessage();
      if (str != null && str.length() != 0) {
	fatalError("Error: " + str, e);
      } else {
	fatalError(e.toString(), e);
      }
    }
    
  }

  //
  // Create a VncCanvas instance.
  //

  void createCanvas(int maxWidth, int maxHeight) throws IOException {
    // Determine if Java 2D API is available and use a special
    // version of VncCanvas if it is present.
    vc = null;
    try {
      // This throws ClassNotFoundException if there is no Java 2D API.
      Class cl = Class.forName("java.awt.Graphics2D");
      // If we could load Graphics2D class, then we can use VncCanvas2D.
      cl = Class.forName("VncCanvas2");
      Class[] argClasses = { this.getClass(), Integer.TYPE, Integer.TYPE };
      java.lang.reflect.Constructor cstr = cl.getConstructor(argClasses);
      Object[] argObjects =
        { this, new Integer(maxWidth), new Integer(maxHeight) };
      vc = (VncCanvas)cstr.newInstance(argObjects);
    } catch (Exception e) {
      System.out.println("Warning: Java 2D API is not available");
    }

    // If we failed to create VncCanvas2D, use old VncCanvas.
    if (vc == null)
      vc = new VncCanvas(this, maxWidth, maxHeight);
  }


  //
  // Process RFB socket messages.
  // If the rfbThread is being stopped, ignore any exceptions,
  // otherwise rethrow the exception so it can be handled.
  //
 
  void processNormalProtocol() throws Exception {
    try {
      vc.processNormalProtocol();
    } catch (Exception e) {
      if (rfbThread == null) {
	System.out.println("Ignoring RFB socket exceptions" +
			   " because applet is stopping");
      } else {
	throw e;
      }
    }
  }


  //
  // Connect to the RFB server and authenticate the user.
  //

  void connectAndAuthenticate() throws Exception
  {
    showConnectionStatus("Initializing...");
    if (inSeparateFrame) {
      vncFrame.pack();
      vncFrame.show();
    } else {
      validate();
    }

    showConnectionStatus("Connecting to " + host + ", port " + port + "...");

    rfb = new RfbProto(host, port, this);
    showConnectionStatus("Connected to server");

    rfb.readVersionMsg();
    showConnectionStatus("RFB server supports protocol version " +
			 rfb.serverMajor + "." + rfb.serverMinor);

    rfb.writeVersionMsg();
    showConnectionStatus("Using RFB protocol version " +
			 rfb.clientMajor + "." + rfb.clientMinor);

    int secType = rfb.negotiateSecurity();
    int authType;
    if (secType == RfbProto.SecTypeTight) {
      showConnectionStatus("Enabling TightVNC protocol extensions");
      rfb.initCapabilities();
      rfb.setupTunneling();
      authType = rfb.negotiateAuthenticationTight();
    } else {
      authType = secType;
    }

    switch (authType) {
    case RfbProto.AuthNone:
      showConnectionStatus("No authentication needed");
      rfb.authenticateNone();
      break;
    case RfbProto.AuthVNC:
      showConnectionStatus("Performing standard VNC authentication");
      if (passwordParam != null) {
        rfb.authenticateVNC(passwordParam);
      } else {
        String pw = askPassword();
        rfb.authenticateVNC(pw);
      }
      break;
    default:
      throw new Exception("Unknown authentication scheme " + authType);
    }
  }


  //
  // Show a message describing the connection status.
  // To hide the connection status label, use (msg == null).
  //

  void showConnectionStatus(String msg)
  {
    if (msg == null) {
      if (vncContainer.isAncestorOf(connStatusLabel)) {
	vncContainer.remove(connStatusLabel);
      }
      return;
    }

    System.out.println(msg);

    if (connStatusLabel == null) {
      connStatusLabel = new Label("Status: " + msg);
      connStatusLabel.setFont(new Font("Helvetica", Font.PLAIN, 12));
    } else {
      connStatusLabel.setText("Status: " + msg);
    }

    if (!vncContainer.isAncestorOf(connStatusLabel)) {
      GridBagConstraints gbc = new GridBagConstraints();
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      gbc.fill = GridBagConstraints.HORIZONTAL;
      gbc.anchor = GridBagConstraints.NORTHWEST;
      gbc.weightx = 1.0;
      gbc.weighty = 1.0;
      gbc.insets = new Insets(20, 30, 20, 30);
      gridbag.setConstraints(connStatusLabel, gbc);
      vncContainer.add(connStatusLabel);
    }

    if (inSeparateFrame) {
      vncFrame.pack();
    } else {
      validate();
    }
  }


  //
  // Show an authentication panel.
  //

  String askPassword() throws Exception
  {
    showConnectionStatus(null);

    AuthPanel authPanel = new AuthPanel(this);

    GridBagConstraints gbc = new GridBagConstraints();
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.anchor = GridBagConstraints.NORTHWEST;
    gbc.weightx = 1.0;
    gbc.weighty = 1.0;
    gbc.ipadx = 100;
    gbc.ipady = 50;
    gridbag.setConstraints(authPanel, gbc);
    vncContainer.add(authPanel);

    if (inSeparateFrame) {
      vncFrame.pack();
    } else {
      validate();
    }

    authPanel.moveFocusToDefaultField();
    String pw = authPanel.getPassword();
    vncContainer.remove(authPanel);

    return pw;
  }


  //
  // Do the rest of the protocol initialisation.
  //

  void doProtocolInitialisation() throws IOException
  {
    rfb.writeClientInit();
    rfb.readServerInit();

    System.out.println("Desktop name is " + rfb.desktopName);
    System.out.println("Desktop size is " + rfb.framebufferWidth + " x " +
		       rfb.framebufferHeight);

    setEncodings();

    showConnectionStatus(null);
  }


  //
  // Send current encoding list to the RFB server.
  //

  int[] encodingsSaved;
  int nEncodingsSaved;

  void setEncodings()        { setEncodings(false); }
  void autoSelectEncodings() { setEncodings(true); }

  void setEncodings(boolean autoSelectOnly) {
    if (options == null || rfb == null || !rfb.inNormalProtocol)
      return;

    int preferredEncoding = options.preferredEncoding;
    if (preferredEncoding == -1) {
      long kbitsPerSecond = rfb.kbitsPerSecond();
      if (nEncodingsSaved < 1) {
        // Choose Tight or ZRLE encoding for the very first update.
        System.out.println("Using Tight/ZRLE encodings");
        preferredEncoding = RfbProto.EncodingTight;
      } else if (kbitsPerSecond > 2000 &&
                 encodingsSaved[0] != RfbProto.EncodingHextile) {
        // Switch to Hextile if the connection speed is above 2Mbps.
        System.out.println("Throughput " + kbitsPerSecond +
                           " kbit/s - changing to Hextile encoding");
        preferredEncoding = RfbProto.EncodingHextile;