一个简单的TCP模拟实现（一）

现在我想实现一个基于UDP之上，实现可靠的传输。仿造TCP做一个简单的可靠传输，TCP的可靠传输在于：

• 解决了乱序
• 超时重传
• 拥塞控制
• 流量控制

哈哈，工程就叫MUTP好了！

基于socket的大文件传输

这是一个udp传输音乐的例子，6M的音乐最后4M，播放起来有很多模糊的地方，wireshark抓包，发现丢了一些。
MUTP希望能实现可靠传输，传输完整的文件

• client

package main.client;

import main.common.DataPacket;
import main.common.DataPacketHeader;
import main.common.mutpConst;

import java.io.*;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;


/**
 * Created by liqiushi on 2017/11/22.
 */
public class Client {
    public static void main(String[] args) throws IOException {
        
        String dstPort = mutpConst.dstPort;
        String dstHost = mutpConst.dstHost;
        String srcPort = mutpConst.srcPort;
        String srcHost = mutpConst.srcHost;
        InetSocketAddress clientSocketAddr = new InetSocketAddress(srcHost,Integer.parseInt(srcPort));
        InetSocketAddress serverSocketAddr = new InetSocketAddress(dstHost,Integer.parseInt(dstPort));
        try {
            DatagramSocket socket = new DatagramSocket(clientSocketAddr);
    /*      private boolean ACK;
            private boolean SYN;
            private int ackNum;
            private int seqNum;*/
            DataPacketHeader dph = new DataPacketHeader(true,true,1,1);
            DataPacket dp = new DataPacket(dph);
            ByteArrayOutputStream baos = null;
            ObjectOutputStream dos = null;
            //读取文件流
            RandomAccessFile accessFile = null;
            accessFile = new RandomAccessFile("D:/CloudMusic/五月天 - 倔强.mp3","r");
            int readSize = -1;
            int count = 0;
            while((readSize = accessFile.read(dp.getBuf(),0,dp.getBuf().length)) != -1){
                count++;
                baos = new ByteArrayOutputStream();
                dos = new ObjectOutputStream(baos);
                dph.setAckNum(count);
                dph.setSeqNum(readSize);
                dos.writeUnshared(dp);
                dos.flush();
                byte onceBuf[] = baos.toByteArray();
                DatagramPacket dpk = new DatagramPacket(onceBuf,onceBuf.length,serverSocketAddr);
                socket.send(dpk);
                baos.close();
                dos.close();
//                dp.setBuf(new byte[51200]);
            }
            System.out.println(count);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }
}

• server

package main.server;

import main.common.DataPacket;
import main.common.mutpConst;

import java.io.*;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;

/**
 * Created by liqiushi on 2017/11/22.
 */
public class server {
    public static void main(String[] args) {
        String dstPort = mutpConst.dstPort;
        String dstHost = mutpConst.dstHost;
        String srcPort = mutpConst.srcPort;
        String srcHost = mutpConst.srcHost;
        InetSocketAddress clientSocketAddr = new InetSocketAddress(srcHost, Integer.parseInt(srcPort));
        InetSocketAddress serverSocketAddr = new InetSocketAddress(dstHost, Integer.parseInt(dstPort));
        ByteArrayInputStream bais = null;
        ObjectInputStream ois = null;
        DatagramSocket socket = null;
        BufferedOutputStream bos = null; 
        try {
            bos = new BufferedOutputStream(new FileOutputStream("E:/5.mp3"));
            socket = new DatagramSocket(serverSocketAddr);
//            DataPacketHeader dph = new DataPacketHeader(true,true,12,1);
//            DataPacket dp = new DataPacket(dph);
            byte recvBuf[] = new byte[1024 * 100];
           
            DatagramPacket recvDp = new DatagramPacket(recvBuf, recvBuf.length);
            while (true) {
                socket.receive(recvDp);
                System.out.println("发送后包的大小:" + recvDp.getLength());

                bais = new ByteArrayInputStream(recvBuf);
                ois = new ObjectInputStream(bais);
                DataPacket dataPacket = (DataPacket) ois.readObject();
                //Object object = ois.readObject();
                //读入文件
                System.out.println(dataPacket.getHeader().getAckNum());
                byte[] fileByte = dataPacket.getBuf();
                bos.write(fileByte,0,fileByte.length);
              
            }
           // bos.flush();
/*            byte buf[] = baos.toByteArray();
            DatagramPacket dpk = new DatagramPacket(buf,buf.length,serverSocketAddr);
            socket.send(dpk);*/
        } catch (SocketException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bais != null) {
                    bais.close();
                }
                if (ois != null) {
                    ois.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (socket != null) {
                socket.close();
            }
        }
    }
}