reliablesequencer.java

来自「java pos,你可以直接编译运行,」· Java 代码 · 共 292 行

/*
 * Copyright (c) 2000 jPOS.org.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *    "This product includes software developed by the jPOS project 
 *    (http://www.jpos.org/)". Alternately, this acknowledgment may 
 *    appear in the software itself, if and wherever such third-party 
 *    acknowledgments normally appear.
 *
 * 4. The names "jPOS" and "jPOS.org" must not be used to endorse 
 *    or promote products derived from this software without prior 
 *    written permission. For written permission, please contact 
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "jPOS",
 *    nor may "jPOS" appear in their name, without prior written
 *    permission of the jPOS project.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 JPOS PROJECT OR ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the jPOS Project.  For more
 * information please see <http://www.jpos.org/>.
 */

/*
 * $Log: ReliableSequencer.java,v $
 * Revision 1.11  2003/10/13 11:04:19  apr
 * tabs expanded to spaces
 *
 * Revision 1.10  2003/05/16 07:14:32  alwyns
 * Import cleanups. Should work as expected now.
 *
 * Revision 1.9  2003/05/16 04:25:35  alwyns
 * Import cleanups.
 *
 * Revision 1.8  2002/01/14 15:48:26  apr
 * JMX support
 *
 * Revision 1.7  2000/11/02 12:09:17  apr
 * Added license to every source file
 *
 * Revision 1.6  2000/05/23 16:41:12  apr
 * now Configurable (required by QSP)
 *
 * Revision 1.5  2000/04/16 23:53:01  apr
 * LogProducer renamed to LogSource
 *
 * Revision 1.4  2000/03/01 14:44:38  apr
 * Changed package name to org.jpos
 *
 * Revision 1.3  2000/01/11 01:24:40  apr
 * moved non ISO-8583 related classes from jpos.iso to jpos.util package
 * (AntiHog LeasedLineModem LogEvent LogListener LogSource
 *  Loggeable Logger Modem RotateLogListener SimpleAntiHog SimpleDialupModem
 *  SimpleLogListener SimpleLogSource SystemMonitor V24)
 *
 * Revision 1.2  1999/12/21 13:54:33  apr
 * BugFix: get intValue()
 *
 * Revision 1.1  1999/12/21 12:15:09  apr
 * Added ReliableSequencer
 *
 */

package org.jpos.core;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.jpos.util.Loggeable;

import com.sun.jini.reliableLog.LogException;
import com.sun.jini.reliableLog.LogHandler;
import com.sun.jini.reliableLog.ReliableLog;

/**
 * @author [e-mail]
 * @version $Id: ReliableSequencer.java,v 1.11 2003/10/13 11:04:19 apr Exp $
 * @since jPOS 1.1
 *
 * A production grade Sequencer based on com.sun.jini.reliableLog
 * (you'll need a copy of sun-util.jar in your classpath in order 
 * to use it)
 *
 */
public class ReliableSequencer 
    extends LogHandler 
    implements Sequencer, Loggeable, Configurable, ReliableSequencerMBean
{
    private Map map;
    private ReliableLog log;
    public static final int MAXLOGSIZE = 200000;
    public ReliableSequencer () {
        map = new HashMap();
        log = null;
    }

    /**
     * constructs and setup a ReliableSequencer object
     */
    public static ReliableSequencer createInstance (String dir) 
        throws IOException
    {
        ReliableSequencer seq = new ReliableSequencer();
        ReliableLog log = new ReliableLog (dir, seq);
        log.recover();
        log.snapshot();
        seq.setReliableLog (log);
        return seq;
    }

    /**
     * @param cfg containing <code>logdir</code> property
     */
    public void setConfiguration (Configuration cfg) 
        throws ConfigurationException
    {
        try {
            ReliableLog log = new ReliableLog (cfg.get("logdir"), this);
            log.recover();
            log.snapshot();
            setReliableLog (log);
        } catch (IOException e) {
            throw new ConfigurationException (e);
        }
    }

    /**
     * @param counterName
     * @param add increment
     * @return counterName's value + add
     */
    synchronized public int get (String counterName, int add) {
        int i = 0;
        Integer I = (Integer) map.get (counterName);
        if (I != null)
            i = I.intValue();
        I = new Integer (i + add);
        map.put (counterName, I);
        try {
            log.update (new LogEntry (counterName, I), true);
            if (log.logSize() > MAXLOGSIZE)
                log.snapshot();
        } catch (LogException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return I.intValue();
    }
    /**
     * @param counterName
     * @return counterName's value + 1
     */
    public int get (String counterName) {
        return get (counterName, 1);
    }
    /**
     * @param counterName
     * @param newValue
     * @return oldValue
     */
    synchronized public int set (String counterName, int newValue) {
        Integer I = new Integer (newValue);
        Integer oldValue = (Integer) map.put (counterName, I);
        try {
            log.update (new LogEntry (counterName, I), true);
            if (log.logSize() > MAXLOGSIZE)
                log.snapshot();
        } catch (LogException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return oldValue == null ? 0 : oldValue.intValue();
    }

    /**
     * @param log an already recovered - ready to use ReliableLog
     */
    public void setReliableLog (ReliableLog log) {
        this.log = log;
    }

    public void snapshot(OutputStream out) throws Exception
    {
        ObjectOutputStream stream = new ObjectOutputStream(out);
        stream.writeUTF(this.getClass().getName());
        stream.writeObject(map);
        stream.writeObject(null);
        stream.flush();
    }
    public void recover(InputStream in) throws Exception
    {
        ObjectInputStream stream = new ObjectInputStream(in);
        if (!this.getClass().getName().equals(stream.readUTF()))
            throw new IOException("log from wrong implementation");
        map = (Map) stream.readObject();
    }
    public void applyUpdate(Object update) throws Exception
    {
        if (!(update instanceof LogEntry))
            throw new Exception ("not a LogEntry");

        LogEntry entry = (LogEntry) update;
        map.put (entry.key, entry.value);
    }

    public static class LogEntry implements Serializable {
        public Object key, value;
        public LogEntry (Object key, Object value) {
            this.key = key;
            this.value = value;
        }
    }
    
    public void dump (PrintStream p, String indent) {
        String inner = indent + "  ";
        p.println (indent + "<reliable-sequencer>");
        Iterator i = map.entrySet().iterator();
        while (i.hasNext()) {
            Map.Entry e = (Map.Entry) i.next();
            p.println (inner + "<seq name=\""+e.getKey()
                              +"\" value=\""+e.getValue()+"\"/>"
            );
        }

        p.println (indent + "</reliable-sequencer>");
    }

    public String[] getCounterNames () {
        Object[] o = map.keySet().toArray();
        String[] s = new String [o.length];
        System.arraycopy (o, 0, s, 0, o.length);
        return s;
    }

    public static int usage () {
        System.out.println ("Usage: ReliableLog logdir counterName intValue");
        return 1;
    }

    public static void main (String args[]) {
        if (args.length < 3)
            System.exit (usage());

        String dir = args[0];
        String key = args[1];
        int val    = Integer.parseInt (args[2]);

        try {
            ReliableSequencer seq = ReliableSequencer.createInstance(dir);
            System.out.println (key + " was " + seq.set (key, val));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}