/*接收一个分组*/ /*返回值说明: * 1.如果正常接收,返回读取数据的长度 * 2.如果接收超时,返回-1 //此句已经无效 * 3.如果接收到本分组的分组头,返回-2 * 4.如果接收到新的发送完毕包,返回-3 * 5.如果接收到上次的发送完毕包,返回-4 * 6.其他情况,返回-5 */ //此函数只用于接收,不发送任何信息.遇到错误,只是将错误标识返回. //如果接收到的是分组包,将其存入buffer中相应位置,返回数据的长度 public int GetDatagramData(int numberRandom, int random, byte[] buffer, bool[] receiveTip, int[] startTip) { //设置不接收超时 //try //{ // socket.setSoTimeout(0); //} //catch (SocketException ex) //{ // // Logger.getLogger(ReceiveLittle.class.getName()).log(Level.SEVERE, null, ex); // logger.error("{}", ex); //} udpReceiveClient.Client.ReceiveTimeout = 0; byte[] receiveBuffer = new byte[DataTip[0]]; //DatagramPacket packet = new DatagramPacket(receiveBuffer, receiveBuffer.length); try { ByteChange.CleanByte(receiveBuffer); //socket.receive(packet); receiveBuffer = udpReceiveClient.Receive(ref host); //receiveState.addHaveReceiveBytes(packet.getLength()); //就算收到未接收请求重发包,有意义的随机数也应该是与本分组随机数相同的 //次随机数 if (ByteChange.ByteToInt(receiveBuffer, DataTip[2]) != numberRandom) { return(-5); } //所以,先判断块随机数 int r = ByteChange.ByteToInt(receiveBuffer, DataTip[3]); if (r != random) { return(-5); } //判断分组标识 //String s = new String(receiveBuffer, DataTip[1], 4); String s = Encoding.Default.GetString(receiveBuffer, DataTip[1], 4); //if (!s.equals(datagramData)) if (!datagramData.Equals(s)) { //如果此包不是分组包 //判断其是否是本分组的分组头.由于随机数已经匹配,所以,只需要判断标识 //if (s.equals(datagramHead)) if (datagramHead.Equals(s)) { return(-2); } //再判断其是否是发送完毕包 //if (s.equals(datagramFinish)) if (datagramFinish.Equals(s)) { //先判断,是否是新的发送完毕包 r = ByteChange.ByteToInt(receiveBuffer, FinishTip[4]); if (!littleRandomStack.InIt(r)) { littleRandomStack.Add(r); return(-3); } //如果是上次的发送完毕包 int r2 = littleRandomStack.GetLast(); if (r2 != -1 && r2 == r) { return(-4); } } //否则,返回-5 return(-5); } //至此已经是分组包了,先判断一下包的完整性 //因为,如果包是不完整的,它的数据就是有问题的,是不能接收的 //s = new String(receiveBuffer, DataTip[7], 4); s = Encoding.Default.GetString(receiveBuffer, DataTip[7], 4); //if (!s.equals(datagramTail)) if (!datagramTail.Equals(s)) { return(-5); } //包是完整的,获取包的序号 int serial = ByteChange.ByteToShort(receiveBuffer, DataTip[4]); int number = ByteChange.ByteToShort(receiveBuffer, DataTip[5]); //如果该序列的包未被正确接收 if (!receiveTip[serial]) { receiveTip[serial] = true; for (int i = 0; i < number; i++) { buffer[i + startTip[serial]] = receiveBuffer[i + DataTip[6]]; } return(number); } //如果已经被正确接收了,则丢弃该包 else { return(-5); } } catch (Exception ex) { //Logger.getLogger(Receive.class.getName()).log(Level.SEVERE, null, ex); if (ex is TimeoutException) { return(-1); } if (ex is SocketException) { return(-1); } return(-5); } }
/* 接收请求重发包 */ /* 返回接收方是否接收完毕 */ public bool GetDatagramReq(int numberRandom, int blockRandom, int littleRandom, bool[] sendTip) { //log.Info("GetDatagramReq进入"); // 首先,设置接收超时5ms //DatagramPacket packetReq = null; // 由于请求重发包发送的是需要重发的分组 // 所以,先将成功发送标记全部置true,再根据 for (int i = 0; i < sendTip.Length; i++) { sendTip[i] = true; } // 请求重发包将发送失败的置false byte[] buffer = new byte[ReqAgainTip[0]]; bool canSendFinish = true; while (true) { try { if (canSendFinish) { udpSendClient.Client.ReceiveTimeout = sendState.WaitTime; SendFinish(numberRandom, blockRandom, littleRandom); } ByteChange.CleanByte(buffer); buffer = udpSendClient.Receive(ref host); // 如果接收到数据包,不管是否正确,下一轮都不能发未接收请求重发包 canSendFinish = false; // 对接收到的请法求重发包进行解析 // 检证是不是请求重发包 String s = Encoding.Default.GetString(buffer, ReqAgainTip[1], 4); if (!datagramReqAgain.Equals(s)) { continue; } // 匹配次随机数 int r = ByteChange.ByteToInt(buffer, ReqAgainTip[2]); if (r != numberRandom) { continue; } // 匹配块随机数 r = ByteChange.ByteToInt(buffer, ReqAgainTip[3]); if (r != blockRandom) { continue; } // //验证该包是否完整 // s=new String(buffer,1014,4); // if(!s.equals(datagramTail)){ // continue; // } // 验证此请求重发包的小随机数是否与本次发送的"发送完毕包"相同 r = ByteChange.ByteToInt(buffer, ReqAgainTip[4]); if (r != littleRandom) { continue; } // 验证完毕,提取请求重发的分组 // 提取数据长度 int length = ByteChange.ByteToShort(buffer, ReqAgainTip[5]); // 如果数据长度是0,验证一下数据完整性,如果完整,则返回数据接收完毕 if (length == 0) { //s = new String(buffer, ReqAgainTip[5] + 2, 4); s = Encoding.Default.GetString(buffer, ReqAgainTip[5] + 2, 4); //if (s.equals(datagramTail)) if (datagramTail.Equals(s)) { // 数据完整,返回 //log.Info("GetDatagramReq退出true"); return(true); } else { // 数据不完整,此包无效,继续循环 continue; } } else { sendState.NumResendPackets = 0; for (int i = 0; i < length; i++) { int tip = ByteChange.ByteToShort(buffer, i * 2 + ReqAgainTip[6]); sendTip[tip] = false; sendState.AddNumResendPackets(); } //log.Info("GetDatagramReq退出"); break; } } catch (SocketException ex) { // Logger.getLogger(Send.class.getName()).log(Level.SEVERE,null, ex); // 如果是接收超时,那么下一次循环就应该发送"发送完毕包" if (ex.ErrorCode == 10060) { canSendFinish = true; int time = sendState.WaitTime; if (time <= 1800 && time > 0) { sendState.WaitTime = (time + 10);//延迟时间+10 } } } } return(false); }
/*接收分组头*/ //1.不接收超时. 2.接收成功,会调用发送分组头确认包 public Rdh_return ReceiveDatagramHead(int numberRandom) { byte[] buffer = new byte[FilePropertyTip[0]]; //DatagramPacket packet = null; Rdh_return rdh = new Rdh_return(); //设置不接收超时 udpReceiveClient.Client.ReceiveTimeout = 0; while (true) { try { //packet = new DatagramPacket(buffer, buffer.length);//,InetAddress.getByName(yourAddress),yourPort ByteChange.CleanByte(buffer); //socket.receive(packet); //receiveState.addHaveReceiveBytes(packet.getLength()); buffer = udpReceiveClient.Receive(ref host); //检查分组头标识 //String str = new String(buffer, HeadTip[1], 4); String str = Encoding.Default.GetString(buffer, HeadTip[1], 4); //if (!str.equals(datagramHead)) if (!datagramHead.Equals(str)) { /*既然不是分组头,重新接收是肯定的.只不过,有些情况,需要处理一下再重新接收*/ //如果是开始传输包 //if (str.equals(datagramStart)) if (datagramStart.Equals(str)) { int num = ByteChange.ByteToInt(buffer, StartTip[2]); if (num == numberRandom) { SendStartAck(numberRandom); // System.out.println("在分组头中接收到开始传输包"); continue; } } //如果是发送完毕包 //if (str.equals(datagramFinish)) if (datagramFinish.Equals(str)) { //先检其次随机数 if (ByteChange.ByteToInt(buffer, FinishTip[2]) == numberRandom) { //检验是不是上一次的发送完毕包 //如果是的,说明上次发的0请求重发包没发成功 //先检查其块随机数是不是上一次的 if (randomStack.GetLast() != -1 && ByteChange.ByteToInt(buffer, FinishTip[3]) == randomStack.GetLast()) { //再检查其小随机数,是不是上次的(即最后一次发过来的) if (littleRandomStack != null) { //如果littelRandomStack是null,说明这是第一次接收分组头,当然不可能要重发 if (littleRandomStack.GetLast() == ByteChange.ByteToInt(buffer, FinishTip[4])) { //如果小随机数也匹配,则发送上次的0请求重发包 if (lastReqAgainBuffer != null) { //socket.send(lastReqAgain); udpReceiveClient.Send(lastReqAgainBuffer.ToArray(), lastReqAgainBuffer.Count, host); } } } } } } //如果是传输结束包,则将0分组数量填充入rdh,然后返回 //if (str.equals(datagramStop)) if (datagramStop.Equals(str)) { rdh.Number = 0; return(rdh); } continue; } //检查该包是否完整 //str = new String(buffer, HeadTip[5], 4); str = Encoding.Default.GetString(buffer, HeadTip[5], 4); //if (!str.equals(datagramTail)) if (!datagramTail.Equals(str)) { continue; } //检查完毕,获取随机数 rdh.Random = ByteChange.ByteToInt(buffer, HeadTip[3]); //获取分组数量 rdh.Number = ByteChange.ByteToShort(buffer, HeadTip[4]); SendDatagramHeadAck(numberRandom, rdh.Random); break; } catch (Exception ex) { //MessageBox.Show(ex.ToString()); // Logger.getLogger(ReceiveLittle.class.getName()).log(Level.SEVERE, null, ex); //logger.error("{}", ex); } } return(rdh); }