java NIO 学习 聊天室程序 （2）

有了Command 接口，我们可以定义一些命令：
这些命令也代表了一些基本的需求

1. @pub 向聊天室中发广播消息
2. @quit 退出聊天室   ， 如果断线，聊天室可以自动将与客户端的连接断开
3. @listmember  查看聊天室中的所有人
4. @login  username password  以用户名和密码登陆服务器
5. @regist  username password 注册用户
6. @usr  username|socket address 向特定用户发消息

有了以上需求的话，我们就需要定义一些数据结构：
首先定义会员类：

package com.tcl.chat;

import java.lang.Thread.State;

/**
 * 会员类
 * 
 * @author tmdpzc
 * 
 */
public class Member {
	private String mUsername;
	private String mPassword;

	private MemberState mState;
	/**
	 * 定义会员的状态
	 * @author tmdpzc
	 *
	 */
	static class MemberState {
		public static final int OFFLINE = 0;
		public static final int UNLOGIN = 1;
		public static final int ONLINE = 2;
		public int state = 0;

		public MemberState() {
			// do nothing
		}

		public void setState(int state) {
			this.state = state;
		}

	}

	public boolean login(String username, String password) {
		if (this.mUsername.equals(username) && this.mPassword.equals(password)) {
			online();
			return true;
		}
		return false;
	}
	public void connected(){
		mState.setState(MemberState.UNLOGIN);
	}
	
	private void online() {
		mState.setState(MemberState.ONLINE);
	}

	public void offline() {
		mState.setState(MemberState.OFFLINE);
	}

	public Member(String username, String password) {
		super();
		this.mUsername = username;
		this.mPassword = password;
		this.mState = new MemberState();
	}

	public String getUsername() {
		return mUsername;
	}

	public void setUsername(String username) {
		this.mUsername = username;
	}

	public String getPassword() {
		return mPassword;
	}

	public void setPassword(String password) {
		this.mPassword = password;
	}

}

定义一个存储会员的接口，可以理解为这是一个key-value 的数据库：

package com.tcl.chat;

public interface MemberStorage {
	public boolean register(Member m);
	public boolean has(String m);
	public Member get(String name);
}

既然是简单的NIO 聊天室，就使用一个Map来存储Member的数据好了
一个实现MemberStorage接口的类

package com.tcl.chat.impl;

import java.util.HashMap;

import com.tcl.chat.Member;
import com.tcl.chat.MemberStorage;

public class MemberStorageImpl implements MemberStorage{
	private HashMap<String, Member> mStorage;
	
	public  MemberStorageImpl(int size){
		mStorage = new HashMap<String, Member>(size);
	}

	@Override
	public boolean register(Member m) {
		if (has(m.getUsername())) {
			return false;
		}else {
			mStorage.put(m.getUsername(), m);
		}
		return true;
	}

	@Override
	public boolean has(String name) {
		Member m = mStorage.get(name);
		if (m == null) {
			return false;
		}else {
			return true;
		}
	}

	@Override
	public Member get(String name) {
		return mStorage.get(name);
	}
}

在ChatServer类中有这么几个Map：

Map<String, SocketChannel> mChannelMap;//socket address 到 SocketChannel的映射
Map<String, Member>  mLoginMemberMap; //socket address  到 member的映射；
MemberStorage mMemberStorage; //所有会员的记录；

这些基础设施建立好了，后面就可以实现我们的命令了，也就是具体的功能。
首先是PubCmd：

package com.tcl.chat.command;

import java.io.IOException;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;

import com.tcl.chat.ChatServer;

public class PubCmd extends Command {

	@Override
	public void handleCmd(SelectionKey key, ChatServer server, String[] args)
			throws IOException {
		SocketChannel sc = (SocketChannel) key.channel();
		StringBuilder sb = new StringBuilder();
		if (args.length <= 1) {
			return;
		} else {
			for (int i = 1; i < args.length; i++) {
				sb.append(args[i]);
			}
		}

		String pub_msg = sc.socket().getRemoteSocketAddress() + ": "
				+ sb.toString();
		System.out.println(pub_msg);
		Iterator<SelectionKey> it = key.selector().keys().iterator();
		while (it.hasNext()) {
			SelectionKey sKey = (SelectionKey) it.next();
			if ((sKey != key) && (sKey != server.getServerKey())) {
				String address = ((SocketChannel) sKey.channel()).socket()
						.getRemoteSocketAddress().toString();
				if (server.getLoginMemberMap().get(address) == null) {
					return;// 未登陆成功的终端看不到消息
				}
				if (sKey.attachment() == null) {
					sKey.attach(pub_msg);
				} else {
					String at = (String) sKey.attachment();
					sKey.attach(at + pub_msg);
				}
				sKey.interestOps(sKey.interestOps() | SelectionKey.OP_WRITE);
			}
		}
	}

}

再来RegistCmd

package com.tcl.chat.command;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;

import com.tcl.chat.ChatServer;
import com.tcl.chat.Member;
import com.tcl.chat.utils.LogUtil;

public class RegistCmd extends Command {
	private static ByteBuffer ERROR = ByteBuffer
			.wrap("Error regist username and password".getBytes());
	private static ByteBuffer SUCCESS = ByteBuffer.wrap("Regist success"
			.getBytes());

	@Override
	public void handleCmd(SelectionKey key, ChatServer server, String[] args)
			throws IOException {
		// TODO Auto-generated method stub
		LogUtil.i("Regist CMD :");
		SocketChannel sc = (SocketChannel) key.channel();
		LogUtil.e("args length " + args.length);
		if (args.length == 3) {
			String username = args[1];
			String password = args[2];
			Member mb = new Member(username, password);
			boolean flag = server.getMemberStorage().register(mb);
			if (flag) {
				sc.write(SUCCESS);
				SUCCESS.flip();
				return;
			}
		}
		sc.write(ERROR);
		ERROR.flip();//要注意，ByteBuffer要 调用filp才能在第二次的时候重新发送
		return;
	}
}