restservice.java

一个工作流设计及定义的系统,可以直接与数据库结合进行系统工作流程的定义及应用.

/*
 * Copyright (c) 2005, John Mettraux, OpenWFE.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:
 * 
 * . 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 the "OpenWFE" 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.
 *
 * $Id: RestService.java,v 1.11 2005/05/17 16:40:15 jmettraux Exp $
 */

//
// RestService.java
//
// [e-mail]
//
// generated with 
// jtmpl 1.0.04 31.10.2002 John Mettraux ([e-mail])
//

package openwfe.org.rest;

import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.nio.channels.ReadableByteChannel;

import openwfe.org.MapUtils;
import openwfe.org.Application;
import openwfe.org.ServiceException;
import openwfe.org.ApplicationContext;
import openwfe.org.xml.XmlUtils;
import openwfe.org.net.NetUtils;
import openwfe.org.net.SocketService;
import openwfe.org.time.Time;


/**
 * http listening
 * (London Calling ?)
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Date: 2005/05/17 16:40:15 $
 * <br>$Id: RestService.java,v 1.11 2005/05/17 16:40:15 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public class RestService

    extends SocketService

{

    private final static org.apache.log4j.Logger log = org.apache.log4j.Logger
        .getLogger(RestService.class.getName());

    //
    // CONSTANTS & co

    public final static int DEFAULT_PORT 
        = 6080;

    /** 
     * Use this parameter name ('serverName') to tell the service what
     * is the server name to be advertised to the client.
     */
    public final static String P_SERVER_NAME
        = "serverName";

    /**
     * Use this parameter ('restSessionClass') to tell the service which
     * RestSession implementation it should use.
     */
    public final static String P_REST_SESSION_CLASS
        = "restSessionClass";

    /**
     * Use this parameter name ('purgeFrequency') to tell the RestService
     * how frequently it should check for timed out sessions.
     */
    public final static String P_PURGE_FREQUENCY
        = "purgeFrequency";

    /**
     * Use this parameter name ('sessionTimeout') to tell the RestService
     * what is the max idle time for a REST session.
     */
    public final static String P_SESSION_TIMEOUT
        = "sessionTimeout";

    protected final static String DEFAULT_SERVER_NAME
        = "$Id: RestService.java,v 1.11 2005/05/17 16:40:15 jmettraux Exp $";

    protected final static long DEFAULT_PURGE_FREQUENCY
        = Time.parseTimeString("2m");

    protected final static long DEFAULT_SESSION_TIMEOUT
        = Time.parseTimeString("10m");

    //
    // FIELDS

    private java.util.Map unmodifiableServiceParams = null;

    private String serverName = null;

    private String restSessionClassName = null;

    private java.util.Map sessions = new java.util.HashMap();

    private java.util.TimerTask timeOutTask = null;

    private Long lastGivenId = new Long(-1);

    //
    // CONSTRUCTORS

    public void init 
        (final String serviceName, 
         final ApplicationContext context, 
         final java.util.Map serviceParams)
    throws 
        ServiceException
    {
        setDefaultPort(DEFAULT_PORT); // else it will listen on 7000...

        super.init(serviceName, context, serviceParams);

        this.unmodifiableServiceParams = java.util.Collections
            .unmodifiableMap(serviceParams);

        //
        // determining serverName
        
        this.serverName = MapUtils.getAsString
            (serviceParams, P_SERVER_NAME, DEFAULT_SERVER_NAME);

        //
        // determining RestSession implementation to use
        
        this.restSessionClassName = MapUtils.getAsString
            (serviceParams, P_REST_SESSION_CLASS);

        try
        {
            final Class c = Class.forName(this.restSessionClassName);
            final RestSession tmpSession = (RestSession)c.newInstance();

            //
            // the tmpSession establishment is performed once at initialization
            // of the RestService. If succesfull, it proves that the 
            // wrapped around RestSession is operational and thus that the
            // RestService is operational.
            //
        }
        catch (final Throwable t)
        {
            throw new ServiceException
                ("Cannot use RestSession of class "+this.restSessionClassName, 
                 t);
        }

        //
        // starting session timeout system
        
        long timeout = MapUtils.getAsLong
            (serviceParams, P_SESSION_TIMEOUT, DEFAULT_SESSION_TIMEOUT);
        long frequency = MapUtils.getAsLong
            (serviceParams, P_PURGE_FREQUENCY, DEFAULT_PURGE_FREQUENCY);

        log.info("Session timeout set to "+timeout+" ms");
        log.info("Purge frequency set to "+frequency+" ms");

        final long finalTimeout = timeout;

        this.timeOutTask = new java.util.TimerTask()
        {
            public void run ()
            {
                timeOutSessions(finalTimeout);
            }
        };

        Application.getTimer().schedule(this.timeOutTask, 15, frequency);

        //
        // done

        log.info("Service '"+getName()+"' ready.");
    }

    //
    // METHODS

    public String getServerName ()
    {
        return this.serverName;
    }

    public String getRestSessionClassName ()
    {
        return this.restSessionClassName;
    }

    //
    // METHODS from Service

    public org.jdom.Element getStatus ()
    {
        org.jdom.Element result = new org.jdom.Element(getName());

        result.addContent(XmlUtils.getClassElt(this));
        result.addContent(XmlUtils.getRevisionElt("$Id: RestService.java,v 1.11 2005/05/17 16:40:15 jmettraux Exp $"));

        return result;
    }

    //
    // METHODS from SocketService

    public void handle (final SelectionKey key)
        throws ServiceException
    {
        try
        {
            final SocketChannel channel = (SocketChannel)key.channel();

            log.debug
                ("Incoming connection from "+
                 channel.socket().getInetAddress());

            final byte[] request = extractRequest(channel);

            if ( ! verify(key, request)) return;

            final Long sessionId = extractSessionId(request);

            if (sessionId == null)
                //
                // authenticate
            {
                authenticate(key, request);
            }
            else
                //
                // is the session registered ?
            {
                final RestSession session = (RestSession)this.sessions
                    .get(sessionId);

                //log.debug
                //    ("Sessions : "+
                //     RestSession.printSessions(this.sessions));

                if (session == null)
                    //
                    // no
                {
                    NetUtils.httpReply
                        (key,
                         404,
                         "No such session",
                         this.serverName,
                         null,
                         "text/plain",
                         null);
                    return;
                }

                //
                // yes

                session.handle(key, request);
            }
        }
        catch (java.io.IOException ie)
        {
            throw new ServiceException
                ("Socket handling failed", ie);
        }
    }

    public void stop ()
        throws ServiceException
    {
        this.timeOutTask.cancel();
        log.info("timeout system for rest sessions stopped.");

        super.stop();
    }

    //
    // METHODS

    private void authenticate (SelectionKey key, byte[] request)
    {

        Exception exception = null;
            // perhaps some exception will be lodged here. Hope none...

        //
        // is it an authorization request
        // or whatever else ?
        
        String sAuth = extractHeaderValue(request, "Authorization");

        if (sAuth != null)
        {
            if ( ! sAuth.toLowerCase().startsWith("basic"))
            {
                NetUtils.httpReply
                    (key,
                     401,
                     "Unauthorized: only 'BASIC' authentication supported",
                     this.serverName,
                     null,
                     "text/plain",
                     null);
                return;