attachment.java

一套MMORPG手机网络游戏的服务端

/*
 * Created on 2005-4-20
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package com.swing.server.common;

import java.nio.BufferUnderflowException;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;

import org.apache.log4j.Logger;

/**
 * @author vampire_a
 * 
 * TODO To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
public class Attachment {
    /** number of bytes in the network event header */
    public static final int HEADER_SIZE = 9;

    public static final String EVENT_END = "end";
    
    public static final int SOCKET = 0;
    
    public static final int POST = 1;
    
    public static final int GET = 2;

    public static final int OTHER = 3;
    
    /** log4j logger */
    private static Logger log = Logger.getLogger("Attachment");

    /** unique id for this client */
    String clientId;

    /** 请求类型
     * SOCKET 	: 0
     * POST 	: 1
     * GET		: 2
     * OTHER	: 3
     */
    public int type;

    /** hash code of the GameName this event should be routed to */
    public String gameCode;

    /** do we have a full header yet */
    private boolean gotHeader;

    /** buffer used to hold data as it's read from the channel */
    public ByteBuffer readBuff;

    public int payloadSize;
    /** temporary storage of the payload before it is read into an event */
    public byte payload[];

    public Map httpHeader = new HashMap();
    
    public StringBuffer sb = new StringBuffer();

    /**
     * constructor. initiales the payload array and the read buffer
     */
    public Attachment() {
        payload = new byte[Globals.MAX_IN_EVENT_SIZE];
        readBuff = ByteBuffer.allocateDirect(Globals.NET_BUFFER_SIZE);
        // readBuff.order(ByteOrder.LITTLE_ENDIAN);
    }

    /**
     * checks if a full event has been read
     * 这个函数里面的两个函数要仔细考虑怎么写，很关键，要区分是Socket连接还是HTTP连接，还要处理是不是结束一个请求，并把数据读出来
     * 
     * @return true if the event is ready, otherwise false
     */
    public boolean eventReady() throws IllegalArgumentException { 
        if(checkHeader() && checkPayload())
            return true;
        else
            return false;
    }

    /**
     * reset the attachment to prepare for reading the next event
     */
    public void reset() {
        gotHeader = false; 
    }

    /**
     * 区分属于哪种类型的上行数据，然后根据读取游戏代号和数据包长度（不同类型数据包读取的方法不同）
     * 
     * @return true if the header is fully available, otherwise false
     * 
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * 						数据包格式（SOCKET）					 *
     * 	包类型（SOCK）  *	  游戏代码  *	  数据包长度  *	数据			 *
     * 	  0 - 3				4			5 - 8		 	  		 *
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * 						数据包格式（POST）						 *
     * 	包类型（POST）  *   HTTP包头数据（包括游戏代码，数据包长度）  *	 *
     * 	  0 - 3					以/r/n/r/n结尾					 *
     * 	数据  *													 *
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     *  					其他请求（OTHER）						 *
     * 	包类型   *	 HTTP包头数据   *								 *
     * 	0 - 3		以/r/n/r/n结尾								 *
     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    
    private boolean checkHeader() throws IllegalArgumentException {
        if (gotHeader)
            return true;
        if (readBuff.remaining() >= HEADER_SIZE) {
            byte[] head = new byte[4];
            
            readBuff.get(head, 0, 4);
            String header = new String(head);
            
            // 用HTTP协议访问服务器端的手机请求
            if (header.equals ("POST")) {
                this.type = POST;
                HTTPUtils.filter(readBuff, httpHeader, sb);
                String length = (String) httpHeader.get("Content-Length");
                if (length != null)
                    payloadSize = Integer.parseInt (length);
                gameCode = (String) httpHeader.get("Code");
            }
            // 用Socket协议访问服务器的手机请求
            else if (header.equals ("SOCK")) {
                this.type = SOCKET;
                gameCode = String.valueOf((char)readBuff.get());
                payloadSize = readBuff.getShort();
                log.debug("Payload Size = " + payloadSize);
            }
            // 用浏览器访问的
            else if (header.equals("GET ")) {
                this.type = GET;
                HTTPUtils.filter(readBuff, httpHeader, sb);
                payloadSize = 0;
                gameCode = "";
            }
            // 其他的访问请求，需要返回一段内容
            else {
                this.type = OTHER; 
                payloadSize = 0;
                gameCode = "";
            }
            
            // readBuff.compact();
            
            if (payloadSize > Globals.MAX_IN_EVENT_SIZE) 
        		throw new IllegalArgumentException("Header specifies payload size (" + 
        						   payloadSize + ") greater than MAX_EVENT_SIZE(" + 
        						   Globals.MAX_IN_EVENT_SIZE + ")");
            // check bounds on the payload
            gotHeader = true;
            return true;
        } else {
            return false;
        }
    }

    /**
     * check for a complete payload
     */
    private boolean checkPayload() {
        if (readBuff.remaining() >= payloadSize) {
            try {
                readBuff.get(payload, 0, payloadSize);
            } catch (BufferUnderflowException bue) {
                log.error("buffer underflow", bue);
            }
            return true;
        }
        else
    	    return false;
    }
}// Attachment