com.sshtools.j2ssh.forwarding.XDisplay.java Source code

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Here is the source code for com.sshtools.j2ssh.forwarding.XDisplay.java

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/*
 *  SSHTools - Java SSH2 API
 *
 *  Copyright (C) 2002 Lee David Painter.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *
 *  You may also distribute it and/or modify it under the terms of the
 *  Apache style J2SSH Software License. A copy of which should have
 *  been provided with the distribution.
 *
 *  This program 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
 *  License document supplied with your distribution for more details.
 *
 *  Changes:
 *  (c) 2005-2006 CCLRC.  David Spence: Split up VNC and X code: new file VNCDisplay.java
 *
 *
 */

package com.sshtools.j2ssh.forwarding;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

/**
 *
 *
 * @author $author$
 * @version $Revision: 1.7 $
 */
public class XDisplay {

    private static Log log = LogFactory.getLog(XDisplay.class);

    private void processDisplay(String display) {
        String os = System.getProperty("os.name");
        String arch = System.getProperty("os.arch");
        boolean linux = os.equals("Linux") && arch.equals("i386");
        /*
         * Check if it is a unix domain socket.  Unix domain displays are in
         * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
         *
         * At the moment as we are using a native library we only support 
         * x86 linux... The module could be compiled to run with other UNIXes
         * and architectures if required.
         */
        if (linux && (display.startsWith("unix:") || display.charAt(0) == ':')) {
            /* Connect to the unix domain socket. */
            isLocal = true;
            String rest = display.substring(display.indexOf(":") + 1);
            if (rest.charAt(0) == ':')
                rest = rest.substring(1);
            try {
                if (rest.indexOf(".") >= 0)
                    rest = rest.substring(0, rest.indexOf("."));
                this.display = Integer.parseInt(rest);
            } catch (NumberFormatException e) {
                throw new IllegalArgumentException("Could not parse display number from DISPLAY: " + display);
            }
            host = null;
        } else {
            /*
             * Connect to an inet socket.  The DISPLAY value is supposedly
             * hostname:d[.s], where hostname may also be numeric IP address.
             */
            isLocal = false;
            if (display.indexOf(":") == -1)
                throw new IllegalArgumentException("Could not find ':' in DISPLAY: " + display);
            host = display.substring(0, display.indexOf(":"));
            String rest = display.substring(display.indexOf(":") + 1);
            try {
                if (rest.indexOf(".") >= 0)
                    rest = rest.substring(0, rest.indexOf("."));
                this.display = Integer.parseInt(rest);
            } catch (NumberFormatException e) {
                throw new IllegalArgumentException("Could not parse display number from DISPLAY: " + display);
            }
        }
    }

    private String host;
    private int display;
    private boolean isLocal;

    /**
     * Creates a new XDisplay object.
     *
     * @param string
     */
    public XDisplay() {
        try {
            String display = System.getenv("DISPLAY");
            if (display == null) {
                log.warn("Display not set, trying localhost:0.0");
                processDisplay("localhost:0.0");
            } else {
                processDisplay(display);
            }
        } catch (Error e) { // in 1.4 System.getenv was depricated, it is back in 1.5
            if (!System.getProperty("os.name").startsWith("Window")) {
                try {
                    String cmd = "env";
                    log.debug("Executing " + cmd);
                    Process process = Runtime.getRuntime().exec(cmd);
                    BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
                    String line = reader.readLine();
                    while (line != null) {
                        if (line.startsWith("DISPLAY=")) {
                            processDisplay(line.substring(8));
                            return;
                        }
                        line = reader.readLine();
                    }
                    reader.close();
                    processDisplay(":0.0");
                    return;
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                    processDisplay(":0.0");
                    return;
                } catch (IOException e1) {
                    e1.printStackTrace();
                    processDisplay(":0.0");
                    return;
                }
            } else {
                processDisplay("localhost:0.0");
            }
        }
    }

    /**
     * Creates a new XDisplay object.
     *
     * @param string
     * @param portOffset
     */
    public XDisplay(String string) {
        processDisplay(string);
    }

    /**
     *
     *
     * @param string
     */
    public void setString(String string) {
        processDisplay(string);
    }

    /**
     *
     *
     * @return
     */
    public int getPort() {
        return (getDisplay() + 6000);
    }

    /**
     *
     *
     * @param host if null then connect to local UNIX domain socket
     */
    public void setHost(String host) {
        if (host == null) {
            host = null;
            isLocal = true;
        } else {
            this.host = host;
            isLocal = false;
        }
    }

    /**
     *
     *
     * @param display
     */
    public void setDisplay(int display) {
        this.display = display;
    }

    /**
     *
     *
     * @return
     */
    public boolean isLocalUNIXSocket() {
        return isLocal;
    }

    /**
     *
     *
     * @return
     */
    public String getHost() {
        return host;
    }

    /**
     *
     *
     * @return
     */
    public int getDisplay() {
        return display;
    }

    /**
     *
     *
     * @return
     */
    public String toString() {
        if (isLocal)
            return ":" + getDisplay();
        else
            return getHost() + ":" + getDisplay();
    }
}