remoteprinthandler.java

无线传感器网络节点Sun SPOT管理工具

/*
 * Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved. 
 * 
 * Sun Microsystems, Inc. has intellectual property rights relating to technology embodied in the product that is
 * described in this document. In particular, and without limitation, these intellectual property rights may
 * include one or more of the U.S. patents listed at http://www.sun.com/patents and one or more additional patents
 * or pending patent applications in the U.S. and in other countries.
 * 
 * U.S. Government Rights - Commercial software. Government users are subject to the Sun Microsystems, Inc.
 * standard license agreement and applicable provisions of the FAR and its supplements.
 * 
 * Use is subject to license terms. 
 * 
 * This distribution may include materials developed by third parties. Sun, Sun Microsystems, the Sun logo and
 * Java are trademarks or registered trademarks of Sun Microsystems, Inc. in the U.S. and other countries. 
 * 
 * Copyright (c) 2006 Sun Microsystems, Inc. Tous droits r?serv?s.
 * 
 * Sun Microsystems, Inc. d?tient les droits de propri?t? intellectuels relatifs ? la technologie incorpor?e dans
 * le produit qui est d?crit dans ce document. En particulier, et ce sans limitation, ces droits de propri?t?
 * intellectuelle peuvent inclure un ou plus des brevets am?ricains list?s ? l'adresse http://www.sun.com/patents
 * et un ou les brevets suppl?mentaires ou les applications de brevet en attente aux Etats - Unis et dans les
 * autres pays.
 * 
 * L'utilisation est soumise aux termes du contrat de licence.
 * 
 * Cette distribution peut comprendre des composants d?velopp?s par des tierces parties.
 * Sun, Sun Microsystems, le logo Sun et Java sont des marques de fabrique ou des marques d?pos?es de Sun
 * Microsystems, Inc. aux Etats-Unis et dans d'autres pays.
 */

package org.sunspotworld.remoteprinting;

import java.io.*;
import javax.microedition.io.*;
import java.util.Calendar;

import com.sun.spot.util.IEEEAddress;
import com.sun.spot.util.Utils;

/**
 * An internal auxiliary class used by RemotePrintServer. Each remote printing client
 * has an associate RemotePrintHandler thread that listens for remote printing from
 * the client and when a full line is received it passes it to the local PrintStream
 * for display by the server. Each line is prefixed with a timestamp and the radio
 * address of the client.
 * <p>
 * You should NOT normally instantiate or call this class directly.
 *
 * @author Ron Goldman
 * @see org.sunspotworld.remoteprinting.RemotePrintServer
 */
public class RemotePrintHandler extends Thread {
    
    private final static int BUFFER_SIZE = 256;
    
    private InputStream in = null;
    private boolean running = true;
    private String macAddress;
    private int portNo;
    private String key;
    private PrintStream out;
    private boolean showingTimeStamps = false;
    
    /**
     * Creates a new instance of RemotePrintHandler.
     *
     * @param address the radio address of the remote print client
     * @param port the port to use for remote printing (0-127)
     * @param ps the PrintStream to use to display remote printing
     */
    public RemotePrintHandler(String address, int port, PrintStream ps) {
        macAddress = address;
        portNo = port;
        out = ps;
        key = macAddress + ":" + Integer.toString(getPort());
        try {
            in = Connector.openInputStream("radiostream://" + key);
        } catch (IOException ex) {
            System.out.println("Error opening remote printing connection: " + key + " : " + ex.toString());
        }
    }
    
    /**
     * Return the status of the RemotePrintHandler thread.
     *
     * @return true if the remote printing connection is still open and active
     */
    public boolean isRunning () {
        return running & isAlive();
    } 
    
    /**
     * Cause the RemotePrintHandler thread to stop.
     *
     */
    public void quit () {
        running = false;
        if (in != null) {
            try {
                in.close();
                in = null;
            } catch (IOException ex) {
                // just ignore
            }
        }
    }
    
    /**
     * Simple way to specify a fixed width display for 2-3 digit numbers.
     * Leading zeros are printed if necessary.
     *
     * @param out the PrintStream to write to
     * @param num the number to write out
     * @param digits how many characters to write
     */
    private static void printNumAux (PrintStream out, int num, int digits) {
        if (digits >= 3 & num < 100) out.print('0');
        if (digits >= 2 & num < 10)  out.print('0');
        out.print(num);
    }

    /**
     * Auxiliary function to print a time stamp and identifying SPOT address.
     *
     * @param out the PrintStream to use
     * @param prefix the SPOT IEEE radio address
     */
    public static void printTimeStamp (PrintStream out, String prefix) {
        Calendar c = Calendar.getInstance();
        printNumAux(out, c.get(Calendar.HOUR_OF_DAY), 2);
        out.print(':');
        printNumAux(out, c.get(Calendar.MINUTE), 2);
        out.print(':');
        printNumAux(out, c.get(Calendar.SECOND), 2);
        out.print('.');
        printNumAux(out, c.get(Calendar.MILLISECOND), 3);
        out.print(' ');
        out.print(prefix);
        out.print(' ');
    }

    /**
     * Internal loop to receive lines from the remote print client and display them.
     * Not called directly but via Thread.start().
     */
    public void run () {
        try {
            byte buffer[] = new byte[BUFFER_SIZE];
            IEEEAddress addr = new IEEEAddress (macAddress);
            String prefix = "[" + addr.asDottedHex() + "]";
            int len = 0;
            while (running) {
                int ch = in.read();
                if (ch == -1) {
                    if(showingTimeStamps) printTimeStamp(out, prefix);
                    out.println("Remote printing channel closed " + key);
                    break;
                } else if (ch == '\n') {
                    if(showingTimeStamps) printTimeStamp(out, prefix);
                    out.write(buffer, 0, len);
                    out.println();
                    len = 0;
                } else {
                    buffer[len++] = (byte)ch;
                    if (len >= BUFFER_SIZE) {
                        if(showingTimeStamps) printTimeStamp(out, prefix);
                        out.write(buffer, 0, len);
                        out.println("  [cont...]");
                        len = 0;                    
                    }
                }
            }
        } catch (IOException ex) {
            if (running) {
                out.println("Error reading remote printing: " + key + " : " + ex.toString());
            }
        } finally {
            Utils.sleep(1000);
            if (in != null) {
                try {
                    in.close();
                    in = null;
                } catch (IOException ex) { /* ignore */ }
            }
        }
    }

    public int getPort() {
        return portNo;
    }

    public boolean isShowingTimeStamps() {
        return showingTimeStamps;
    }

    public void setShowingTimeStamps(boolean showingTimeStamps) {
        this.showingTimeStamps = showingTimeStamps;
    }
}