Socket编程

Socket概述

UDP

UDP数据传输流程：

以下是代码实现：


因为UDP是无连接的不可靠传输，所以接收方需要在发送方发送数据之前就启动，否则会接收不到数据。也就是说必须先运行UDPSocketReceive再运行UDPSocketSend。控制台打印如下：
发送方：

Sender Start...

接受方：

Receiver Start...
address:/127.0.0.1---port:61177---content:God bless you!

聊天实现：

package Socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class SocketFemale {
	public static void main(String[] args) {
		try {
			new Thread(new Runnable() {
				@Override
				public void run(){
					try {
						receive();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}).start();
			send();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	//接收消息方法
	private static void receive() throws IOException {
		System.out.println("SocketFemale Receiver Start...");

		//1.创建udp的socket服务,并声明端口号
		DatagramSocket dsReceive = new DatagramSocket(6666);
		//无限循环，一直处于接收状态
		while (true) {
			//2.创建接收数据的数据包
			byte bytes[] = new byte[1024];
			DatagramPacket dp = new DatagramPacket(bytes, bytes.length);

			//3.将数据接收到数据包中
			dsReceive.receive(dp);

			//4.解析数据
			String content = new String(dp.getData(), 0, dp.getLength());
			System.out.println("SocketFemale Receive:" + content);
		}
	}

	private static void send() throws IOException {
		//1.创建socket服务
		DatagramSocket dsSend = new DatagramSocket();

		//将键盘输入的信息转换成输入流再放入到缓冲区
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String line = null;
		while ((line=br.readLine())!=null){
			//2.封装数据
			byte[] bytes = line.getBytes();
			//地址
			InetAddress address =InetAddress.getByName("127.0.0.1");
			//参数：数据、长度、地址、端口
			DatagramPacket dp = new DatagramPacket(bytes,bytes.length,address,7777);

			//3.发送数据包
			dsSend.send(dp);
		}
		//4.关闭socket服务
		dsSend.close();
	}
}

package Socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class SocketMale {
	public static void main(String[] args){
		try {
			new Thread(new Runnable() {
				@Override
				public void run() {
					try {
						receive();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}).start();
			send();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	//接收消息方法
	private static void receive() throws IOException {
		System.out.println("SocketMale Receiver Start...");

		//1.创建udp的socket服务,并声明端口号
		DatagramSocket dsReceive = new DatagramSocket(7777);
		//无限循环，一直处于接收状态
		while (true) {
			//2.创建接收数据的数据包
			byte[] bytes = new byte[1024];
			DatagramPacket dp = new DatagramPacket(bytes, bytes.length);

			//3.将数据接收到数据包中
			dsReceive.receive(dp);

			//4.解析数据
			String content = new String(dp.getData(), 0, dp.getLength());
			System.out.println("SocketMale Receive:" + content);
		}
		//关闭服务
		// ds.close;
	}

	private static void send() throws IOException {
		//1.创建socket服务
		DatagramSocket dsSend = new DatagramSocket();

		//将键盘输入的信息转换成输入流再放入到缓冲区
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String line = null;
		while ((line=br.readLine())!=null){
			//2.封装数据
			byte[] bytes = line.getBytes();
			//地址
			InetAddress address =InetAddress.getByName("127.0.0.1");
			//参数：数据、长度、地址、端口
			DatagramPacket dp = new DatagramPacket(bytes,bytes.length,address,6666);

			//3.发送数据包
			dsSend.send(dp);
		}
		//4.关闭socket服务
		dsSend.close();
	}
}

TCP

TCP聊天实现：
一个服务端可以同时和多个客户端进行通信。如何区分不同客户端？服务端首先通过accept获取到客户端Socket，然后通过客户端的Socket获取的流进行通讯，服务端得以区分每个客户端。