socket编程---一个简单例子

服务器端代码(单线程):

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
 
public class TalkServer {
 
    public static void main(String[] args) {
        ServerSocket server = null;
        try {
            server = new ServerSocket(4700);
        } catch (IOException e) {
            System.out.println("Can not listen 4700.");
        }
        Socket socket = null;
        try {
            socket = server.accept();
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        String line;
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter printWriter = new PrintWriter(socket.getOutputStream());
            BufferedReader sysin = new BufferedReader(new InputStreamReader(System.in));
            System.out.println("Client:" + reader.readLine());
            line = sysin.readLine();
            while (!line.equals("bye")) {
                printWriter.print(line);
                printWriter.flush();
                System.out.println("Server:" + line);
                System.out.println("Client:" + reader.readLine());
                line = sysin.readLine();
            }
            reader.close();
            sysin.close();
            printWriter.close();
            socket.close();
            server.close();
 
        } catch (IOException e) {
            e.printStackTrace();
        }
 
    }
}

客户端代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
 
public class TalkClient {
    public static void main(String[] args) {
        try {
            Socket socket = new Socket("127.0.0.1", 4700);
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter out = new PrintWriter(socket.getOutputStream());
            BufferedReader sysin = new BufferedReader(new InputStreamReader(System.in));
            String readline = sysin.readLine();
            while (!readline.equals("bye")) {
                out.println(readline);
                out.flush();
                System.out.println("Client:" + readline);
                System.out.println("Server:" + in.readLine());
                readline = sysin.readLine();
            }
            in.close();
            out.close();
            sysin.close();
            socket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

服务器端代码(多线程)：

import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
 
public class MultiEchoServer {
    private static ServerSocket serverSocket;
    private static final int PORT = 12345;
 
    public static void main(String[] args) throws IOException {
        try {
            serverSocket = new ServerSocket(PORT);
        } catch (IOException e) {
            System.out.println("Unable connect to the port");
            System.exit(1);
        }
        do {
            Socket client = serverSocket.accept();
            System.out.println("New client accept...");
            ClientHandler clientHandler = new ClientHandler(client);
            clientHandler.start();
        } while (true);
    }
}
 
class ClientHandler extends Thread {
    private Socket client;
    private Scanner input;
    private PrintWriter output;
 
    public ClientHandler(Socket client) {
        this.client = client;
        try {
            input = new Scanner(client.getInputStream());
            output = new PrintWriter(client.getOutputStream(),true);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    @Override
    public void run() {
        String receive = "";
        do {
            receive = input.nextLine();
            System.out.println("Server receive message:" + receive);
            output.println("Echo:" + receive);
        } while (!receive.equalsIgnoreCase("q"));
        try {
            if (client != null) {
                System.out.println("Closing connection...");
                client.close();
            }
        } catch (IOException e) {
            System.out.println("Unable to close connection...");
        }
    }
}

客户端代码：

import java.io.IOException;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;
 
public class MultiEchoClient {
    private static InetAddress host;
    private static final int PORT = 12345;
 
    public static void main(String[] args) {
        try {
            host = InetAddress.getLocalHost();
        } catch (UnknownHostException e) {
            System.out.println("Host id not found!");
            System.exit(1);
        }
        SenderMessages();
    }
 
    public static void SenderMessages() {
        Socket socket = null;
        try {
            socket = new Socket(host, PORT);
            Scanner input = new Scanner(socket.getInputStream());
            PrintWriter outpout = new PrintWriter(socket.getOutputStream(),true);
            Scanner userInput = new Scanner(System.in);
            String message, response;
            do {
                System.out.println("Enter Message:");
                message = userInput.nextLine();
                outpout.println(message);
                response = input.nextLine();
                System.out.println("Server " + response);
            } while (!message.equalsIgnoreCase("q"));
            input.close();
            userInput.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (socket != null) {
                    System.out.println("Closing connetion...");
                    socket.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
 
}