# Dart Socket之TCP粘包

# 什么是TCP粘包

​ socket编程-tcp粘包

# dart中的socket

• RawDatagramSocket ​ 用于UDP通信

*　RawServerSocket、RawSocket、ServerSocket、Socket

​	RawServerSocket，RawSocket：低级别的tcp服务提供类，可用于IP,ICMP协议		

​	ServerSocket、Socket：用于TCP通信

• RawSecureServerSocket，RawSecureSocket、SecureServerSocket、SecureSocket ​ 支持SSL、TSL的安全通信

# dart之udp通信

udp是无状态通信，通常用于服务发现。

//Server端
var udpSocket = await RawDatagramSocket.bind(InternetAddress.anyIPv4, 34343);
//这里要启用广播，重要
udpSocket.broadcastEnabled = true;

await for (var event in udpSocket) {
    if (RawSocketEvent.read == event) {
        var data = udpSocket.receive();
        var result = Utf8Codec().decode(data.data);
        print(result);
    }
}

//Client端
//要创建一个udp实例，必须指定一个端口，即使仅为客户端，端口任意
var client = await RawDatagramSocket.bind(InternetAddress.anyIPv4, 33333);
client.broadcastEnabled = true;
var helloBytes = utf8.encode("hello");
Future.doWhile(() async {
    await Future.delayed(Duration(seconds: 1));
    udpSocket.send(helloBytes, InternetAddress("255.255.255.255"), 34343);
    return true;
});

# dart之tcp通信

//Server端
main(List<String> args) async {
  var server = await ServerSocket.bind(InternetAddress.loopbackIPv4, 33333);
  print("start server....");
  await for (var socket in server) {
    acceptSocket(socket);
  }
}

//接受Client连接
acceptSocket(Socket socket) async {
  await for (var data in socket) {
    print("server:$data");
    send(socket, data);
  }
}

send(Socket socket, data) async {
  sleep(Duration(seconds: 3));
  try {
    socket.add(data);
    await socket.flush();
  } catch (e) {
    print(e);
  }
}

//Client端
main(List<String> args) async {
  var client = await Socket.connect(InternetAddress.loopbackIPv4, 33333);
  var helloBytes = utf8.encode("hello");
  client.add(helloBytes);
  await client.flush();
  
  await for (var data in client) {
    print("clinet:$data");
    send(client, data);
  }
}

send(Socket socket, data) async {
  sleep(Duration(seconds: 3));
  try {
    socket.add(data);
    await socket.flush();
  } catch (e) {
    print(e);
  }
}

# dart之tcp粘包扩展

最近写了一个文件传输工具需要对tcp进行粘包处理，所以实现了几个tcp粘包处理类。

package: d_socket