responder.java

JAVA平台下优秀的CHART开源代码,可以实现类似EXCEL中的二维或三维的饼图/椎图功能.

/**
 * Copyright (C) 2003  Manfred Andres
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * 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
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * 
 * Created on 22.10.2003
 */

package freecs.core;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.Iterator;
import java.util.Set;

import freecs.Server;
import freecs.interfaces.IContainer;
import freecs.util.ObjectBuffer;

/**
 * @author Manfred Andres
 *
 * freecs.core
 */
public class Responder extends Thread {
	public static final Responder res = new Responder();
	private Selector sel;
	
	private Responder() {
		try {
			sel = SelectorProvider.provider().openSelector();
		} catch (Exception e) {
			Server.debug ("Unable to start Listener!", e, Server.MSG_ERROR, Server.LVL_HALT);
		}
	}
	
	public static void startResponder() {
		if (!res.isAlive())
			res.start();
		res.setPriority(MAX_PRIORITY);
	}

	public void addToWrite(SocketChannel sc, ConnectionBuffer cb) {
		if (!cb.isValid())
			return;
		SelectionKey sk = sc.keyFor(res.sel);
		if (sk == null) try {
			sk = sc.register(sel, SelectionKey.OP_WRITE, cb);
		} catch (ClosedChannelException cce) {
			Server.debug ("Responder.addToWrite: Channel closed", cce, Server.MSG_TRAFFIC, Server.LVL_VERY_VERBOSE);
			dropKey(sk);
		}
	}
	
	public void run() {
		while (Server.srv.isRunning() || CentralSelector.cSel.isAlive()) try {
			try {
				sel.selectNow();
			} catch (IOException ioe) {
				Server.debug("Responder.run: ", ioe, Server.MSG_ERROR, Server.LVL_VERBOSE);
			} catch (Exception e) {
				Server.debug("Responder.run: ", e, Server.MSG_ERROR, Server.LVL_MAJOR);
			}
			Set ks = sel.selectedKeys();
			if (ks!=null && !ks.isEmpty()) {
				for (Iterator i = ks.iterator(); i.hasNext(); ) {
					SelectionKey ck = (SelectionKey) i.next();
					i.remove();
					ConnectionBuffer cb = (ConnectionBuffer) ck.attachment();
					if (!cb.isValid()) {
						dropKey (ck);
						continue;
					}
					synchronized (cb) {
						SocketChannel sc = (SocketChannel) ck.channel();
						ObjectBuffer ob = cb.getWriteQueue();
						if (ob.isEmpty()) {
							if (cb.hasToBeClosed()) {
								Server.log ("Responder.run: closing connection (keep-alive-timout)", Server.MSG_TRAFFIC, Server.LVL_VERY_VERBOSE);
								dropKey(ck);
							}
							cb.notifyAll();
							continue;
						}
						IContainer ic = (IContainer) ob.get();
						if (writeContent (sc, ic.getByteBuffer())) {
							ob.pop();
							if (!sc.isOpen() || ic.closeSocket())
								dropKey(ck);
						} else if (!sc.isOpen()) {
							dropKey(ck);
						}
						cb.updateCloseWhen();
						cb.notifyAll();
					}
				}
			}
			try {
				Thread.sleep(33);
			} catch (InterruptedException ie) { }
		} catch (Exception e) {
			Server.debug ("Responder.run: ", e, Server.MSG_ERROR, Server.LVL_MAJOR);
		}
	}
	
	private void dropKey (SelectionKey sk) {
		if (sk == null) 
			return;
		SocketChannel sc = (SocketChannel) sk.channel();
		sk.cancel();
		CentralSelector.dropChannel(sc);
	}
	
	public void dropChannel (SocketChannel sc) {
		SelectionKey sk = sc.keyFor(sel);
		if (sk != null)
			sk.cancel();
	}
	
	/**
	 * writes out the content. if there is nothing more to write in this bytebuffer or
	 * the channel isn't open anymore, true will be returned, false otherwise
	 * @param sc
	 * @param bb
	 * @return
	 * @throws IOException
	 */
	private boolean writeContent (SocketChannel sc, ByteBuffer bb) {
	   int written = 0;
	   try {
		  written = sc.write (bb);
	   } catch (IOException ioe) {
		 // is thrown if the connection was closed from remote host...
		 // do nothing than...
		 Server.log("CentralSelector.writeContent: remote host has closed connection", Server.MSG_TRAFFIC, Server.LVL_VERY_VERBOSE);
		 return true;
	   }
	   if (written < 0) {
		 return true;
	   }
	   if (bb.remaining () > 0)
		  return false;
	   return true;
	}
}