package com.interview.javabasic.socket;

import com.interview.javabasic.thread.MyThread;

import java.net.ServerSocket;
import java.net.Socket;

public class TCPServer {
    public static void main(String[] args) throws Exception {
        //创建socket,并将socket绑定到65000端口
        ServerSocket ss = new ServerSocket(65000);
        //死循环，使得socket一直等待并处理客户端发送过来的请求
        while (true) {
            //监听65000端口，直到客户端返回连接信息后才返回
            Socket socket = ss.accept();
            //获取客户端的请求信息后，执行相关业务逻辑
            new LengthCalculator(socket).start();
        }
    }
}

package com.interview.javabasic.socket;

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class TCPClient {
    public static void main(String[] args) throws Exception {
        //创建socket，并指定连接的是本机的端口号为65000的服务器socket
        Socket socket = new Socket("127.0.0.1", 65000);
        //获取输出流
        OutputStream os = socket.getOutputStream();
        //获取输入流
        InputStream is = socket.getInputStream();
        //将要传递给server的字符串参数转换成byte数组，并将数组写入到输出流中
        os.write(new String("hello world").getBytes());
        int ch = 0;
        byte[] buff = new byte[1024];
        //buff主要用来读取输入的内容，存成byte数组，ch主要用来获取读取数组的长度
        ch = is.read(buff);
        //将接收流的byte数组转换成字符串，这里是从服务端回发回来的字符串参数的长度
        String content = new String(buff, 0, ch);
        System.out.println(content);
        //不要忘记关闭输入输出流以及socket
        is.close();
        os.close();
        socket.close();
    }
}

package com.interview.javabasic.socket;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class LengthCalculator extends Thread {
    //以socket为成员变量
    private Socket socket;

    public LengthCalculator(Socket socket) {
        this.socket = socket;
    }

    @Override
    public void run() {
        try {
            //获取socket的输出流
            OutputStream os = socket.getOutputStream();
            //获取socket的输入流
            InputStream is = socket.getInputStream();
            int ch = 0;
            byte[] buff = new byte[1024];
            //buff主要用来读取输入的内容，存成byte数组，ch主要用来获取读取数组的长度
            ch = is.read(buff);
            //将接收流的byte数组转换成字符串，这里获取的内容是客户端发送过来的字符串参数
            String content = new String(buff, 0, ch);
            System.out.println(content);
            //往输出流里写入获得的字符串的长度，回发给客户端
            os.write(String.valueOf(content.length()).getBytes());
            //不要忘记关闭输入输出流以及socket
            is.close();
            os.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.interview.javabasic.socket;

import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class UDPServer {
    public static void main(String[] args) throws Exception {
        // 服务端接受客户端发送的数据报
        //监听的端口号
        DatagramSocket socket = new DatagramSocket(65001);
        //存储从客户端接受到的内容
        byte[] buff = new byte[100];
        DatagramPacket packet = new DatagramPacket(buff, buff.length);
        //接受客户端发送过来的内容，并将内容封装进DatagramPacket对象中
        socket.receive(packet);
        //从DatagramPacket对象中获取到真正存储的数据
        byte[] data = packet.getData();
        //将数据从二进制转换成字符串形式
        String content = new String(data, 0, packet.getLength());
        System.out.println(content);
        //将要发送给客户端的数据转换成二进制
        byte[] sendedContent = String.valueOf(content.length()).getBytes();
        // 服务端给客户端发送数据报
        //从DatagramPacket对象中获取到数据的来源地址与端口号
        DatagramPacket packetToClient = new DatagramPacket(sendedContent,
                sendedContent.length, packet.getAddress(), packet.getPort());
        //发送数据给客户端
        socket.send(packetToClient);
    }

}

package com.interview.javabasic.socket;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UDPClient {
    public static void main(String[] args) throws Exception {
        // 客户端发数据报给服务端
        DatagramSocket socket = new DatagramSocket();
        // 要发送给服务端的数据
        byte[] buf = "Hello World".getBytes();
        // 将IP地址封装成InetAddress对象
        InetAddress address = InetAddress.getByName("127.0.0.1");
        // 将要发送给服务端的数据封装成DatagramPacket对象 需要填写上ip地址与端口号
        DatagramPacket packet = new DatagramPacket(buf, buf.length, address,
                65001);
        // 发送数据给服务端
        socket.send(packet);

        // 客户端接受服务端发送过来的数据报
        byte[] data = new byte[100];
        // 创建DatagramPacket对象用来存储服务端发送过来的数据
        DatagramPacket receivedPacket = new DatagramPacket(data, data.length);
        // 将接受到的数据存储到DatagramPacket对象中
        socket.receive(receivedPacket);
        // 将服务器端发送过来的数据取出来并打印到控制台
        String content = new String(receivedPacket.getData(), 0,
                receivedPacket.getLength());
        System.out.println(content);

    }

}