Java Socket通信

1、单一客户端与服务器：

package com.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) {
        try {
            // 创建Socket对象，绑定并监听窗口
            ServerSocket serverSocket = new ServerSocket(8888);
            System.out.println("服务器已启动，等待客户端连接...");
            Socket socket = serverSocket.accept();// 监听并接收到此套接字的连接，返回一个Socket对象
            // 根据输入输出流和客户端连接
            InputStream inputStream = socket.getInputStream();// 得到一个输入流，接收客户端传递的信息
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);// 将字节流转换为字符流
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String temp = null;
            String info = "";
            while ((temp = bufferedReader.readLine()) != null) {
                info += temp;
                System.out.println("已收到客户端连接");
                System.out.println("服务端接收到客户端信息：" + info + "当前客户端ip:" + socket.getInetAddress().getHostAddress());
            }
            OutputStream outputStream = socket.getOutputStream();// 获取一个输出流，向服务端发送信息
            PrintWriter printWriter = new PrintWriter(outputStream);
            printWriter.print("你好服务端已收到您的信息");
            printWriter.flush();
            socket.shutdownOutput();// 关闭输出流
            // 关闭对应的资源
            printWriter.close();
            outputStream.close();
            bufferedReader.close();
            inputStream.close();
            socket.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;

public class Client {
    public static void main(String[] args) {
        try {
            // 创建Socket对象
            Socket socket = new Socket("localhost", 8888);
            // 根据输入输出流和服务端连接
            OutputStream outputStream = socket.getOutputStream();// 获取一个输出流，向服务端发送信息
            PrintWriter printWriter = new PrintWriter(outputStream);// 将输出流包装成打印流
            printWriter.print("服务端你好，我是zz");
            printWriter.flush();
            socket.shutdownOutput();// 关闭输出流
            InputStream inputStream = socket.getInputStream();// 获取一个输入流，接收服务端的信息
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);// 包装成字符流，提高效率
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);// 缓冲区
            String info = "";
            String temp = null;// 临时变量
            while ((temp = bufferedReader.readLine()) != null) {
                info += temp;
                System.out.println("客户端接收服务端发送信息：" + info);
            }
            // 关闭相对应的资源
            bufferedReader.close();
            inputStream.close();
            printWriter.close();
            outputStream.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

执行结果：

客户端接收到服务端发送消息：你好服务器已接收到您的消息

服务器已启动，等待客户端连接...
已收到客户端连接
服务端接收到客户端信息：服务端你好，我是zz当前客户端ip:127.0.0.1

2、若要实现多客户端操作，需要涉及到多线程，只要你把每个接收到的Socket对象单独开一条线程，然后用一个死循环while(true)去监听端口就行了，如下代码：

package com.threadsocket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;

public class SocketThread extends Thread{
    private Socket socket;
    public SocketThread(Socket socket) {
        this.socket = socket;
    }
    public void run() {
        //根据输入输出流和客户端连接
        try {
            InputStream inputStream = socket.getInputStream();
            //得到一个输入流，接收客户端传递的信息
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);//提高效率将字节流转化为字符流
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);//加入缓冲区
            String temp = null;
            String info = "";
            while((temp = bufferedReader.readLine())!=null) {
                info+=temp;
                System.out.println("已接收到客户端连接");
                System.out.println("服务端接收到客户端信息："+info+"当前客户端ip为："+socket.getInetAddress().getHostAddress());
            }
            OutputStream outputStream = socket.getOutputStream();//获得一个输出流向服务端发送信息
            PrintWriter printWriter = new PrintWriter(outputStream);//将输出流包装成打印流
            printWriter.flush();
            socket.shutdownOutput();//关闭输出流
            //关闭相对应的资源
            bufferedReader.close();
            inputStream.close();
            printWriter.close();
            outputStream.close();
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.threadsocket;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) {
        try {
            ServerSocket serverSocket = new ServerSocket(8888);
            System.out.println("服务端已启动，等待客户端连接...");
            while(true) {
                Socket socket = serverSocket.accept();//侦听并接收到此套接字的连接返回一个Socket对象
                SocketThread socketThread = new SocketThread(socket);
                socketThread.start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.threadsocket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client {
    public static void main(String[] args) {
        try {
            // 创建Socekt对象
            Socket socket = new Socket("localhost", 8888);
            // 根据输入输出流和服务端连接
            OutputStream outputStream = socket.getOutputStream();// 获取一个输出流向服务端发送信息
            PrintWriter printWriter = new PrintWriter(outputStream);
            printWriter.print("服务端你好，我是客户1");
            printWriter.flush();
            socket.shutdownOutput();// 关闭输出流

            InputStream inputStream = socket.getInputStream();// 获取一个输入流，接收服务端的信息
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);// 包装成字符流，提高效率
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);// 缓冲区
            String info = "";
            String temp = null;// 临时变量
            while ((temp = bufferedReader.readLine()) != null) {
                info += temp;
                System.out.println("客户端接收服务端发送信息：" + info);
            }
            // 关闭相对应的资源
            bufferedReader.close();
            inputStream.close();
            printWriter.close();
            outputStream.close();
            socket.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.threadsocket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client2 {
    public static void main(String[] args) {
        try {
            // 创建Socekt对象
            Socket socket = new Socket("localhost", 8888);
            // 根据输入输出流和服务端连接
            OutputStream outputStream = socket.getOutputStream();// 获取一个输出流向服务端发送信息
            PrintWriter printWriter = new PrintWriter(outputStream);
            printWriter.print("服务端你好，我是客户2");
            printWriter.flush();
            socket.shutdownOutput();// 关闭输出流

            InputStream inputStream = socket.getInputStream();// 获取一个输入流，接收服务端的信息
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);// 包装成字符流，提高效率
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);// 缓冲区
            String info = "";
            String temp = null;// 临时变量
            while ((temp = bufferedReader.readLine()) != null) {
                info += temp;
                System.out.println("客户端接收服务端发送信息：" + info);
            }
            // 关闭相对应的资源
            bufferedReader.close();
            inputStream.close();
            printWriter.close();
            outputStream.close();
            socket.close();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

执行结果：

服务端已启动，等待客户端连接...
已接收到客户端连接
服务端接收到客户端信息：服务端你好，我是客户1当前客户端ip为：127.0.0.1
已接收到客户端连接
服务端接收到客户端信息：服务端你好，我是客户2当前客户端ip为：127.0.0.1

来源：oschina

链接：https://my.oschina.net/u/4306807/blog/4140171