Socket编程（JAVA）（待更新）

1、常用代码

1. UDP 协议下的socket

DatagramSocket sendsocket = new DatagramSocket();
DatagramSocket receivesocket=new DatagramSocket(receiverport);//只用在接收方，相当于绑定端口号
/*
Example:
 
              DatagramSocket s = new DatagramSocket(null);
              s.bind(new InetSocketAddress(8888));
 
Which is equivalent to:
 
              DatagramSocket s = new DatagramSocket(8888);
 */
 
 //设置地址格式
 InetAddress destAddress = InetAddress.getLocalHost();
 
//发送数据，需要知道目的主机的地址toAddr，端口号toPort
 String resendData = hostName+ ": Resending to port " + destPort + ", Seq = " + i;
 byte[] Data = resendData.getBytes();  //需要将数据转化成byte流
 DatagramPacket responsePacket = new DatagramPacket(Data, Data.length,toAddr, toPort);
 receiveSocket.send(responsePacket);
 
 //接收数据
 byte[] bytes = new byte[4096];
 DatagramPacket datagramPacket = new DatagramPacket(bytes, bytes.length);
 sendSocket.receive(datagramPacket);
 String received = new String(bytes, 0, bytes.getLength());