udpmessagedispatcher.java

一个实用工具类

/*
 * Copyright (C) butor.com. All rights reserved.
 *
 * This software is published under the terms of the GNU Library General
 * Public License (GNU LGPL), a copy of which has been included with this
 * distribution in the LICENSE.txt file. 
 */


package org.butor.net.udp;

/**
 * ----------------------------------------------------------------
 * 2000/09/13,fm: Creation
 */
import java.util.Enumeration;

import org.butor.log.Log;
/**
 * Dispatches the command received from datagram to the appropritate
 * org.butor.web.listener.
 *
 * @author Filipe Mateus
 */
public class UDPMessageDispatcher implements Runnable {

	public static final String ALL_REGISTERED_LISTENERS = "*";
	public static final String ALL_REGISTERED_LISTENERS_KEYS = "*,all";
	
	protected String f_message;
	
	public UDPMessageDispatcher(String message) {
		super();

		f_message = message;
	}
	
	public void run() {
		String dest = null, name = null, message = null;
		boolean sendToAll = false, sendToAllIncludingTrace = false;
		
		// specific org.butor.web.listener message.
		int delimPos = f_message.indexOf(" ");
		if (delimPos == -1) {
			/*
			 * only one token found! ==> no org.butor.web.listener specified!
			 * This is mean a message to every registered org.butor.web.listener except "Log trace".
			 */
			sendToAll = true;
			message = f_message;
			dest = "all_listeners_except_trace";
			
		} else {
			dest = f_message.substring(0, delimPos);
			message = f_message.substring(delimPos + 1);
			
			if (ALL_REGISTERED_LISTENERS_KEYS.indexOf(dest) >=0 ) {
				sendToAll = true;
				
				if (dest.equalsIgnoreCase(ALL_REGISTERED_LISTENERS)) {
					sendToAllIncludingTrace = true;
					dest = "all_listeners";
					
				} else {
					dest = "all_listeners_except_trace";
				}

			} else if (UDPService.isSingleListenerMode()) {
				/*
				 * It is single user mode and message not sent to all org.butor.web.listener (name != {*|all})
				 * so we sent it to all listeners except trace.
				 */
				sendToAll = true;
				dest = "all_listeners_except_trace";
				
			} else {
				/*
				 * sent to a particular  org.butor.web.listener
				 */
				name = dest;
			}
		}

		Log.logStr(
			Log.LOG_LEVEL_LOW,
			this,
			Log.LOG_TYPE_INFO,
			"run()",
			"org.butor.web.listener=[" + dest + "], message=[" + message + "]");

		if (sendToAll) {
			// send the message to all registered org.butor.web.listener.
			Enumeration en = UDPService.getListeners().keys();
			while(en != null && en.hasMoreElements()) {
				name = (String) en.nextElement();
				sendMessage(name, message);
			}
			
		} else {
			// send the message to the specified org.butor.web.listener only.
			sendMessage(name, message);
		}
	}
	
	/**
	 * send the message to the specified org.butor.web.listener.
	 */
	protected void sendMessage(String memberName, String message) {
		IUDPMessageListener listener = UDPService.getUdpMessageListener(memberName);
		if (listener == null) {
			Log.logStr(
				this,
				Log.LOG_TYPE_ERROR,
				"run()",
				"org.butor.web.listener not found [" + memberName + "]");
			return;
		}

		listener.handleUdpMessage(message);
	}
}