Android TCP通信：实现网络数据传输

一、TCP/IP协议简介

TCP/IP协议是一组协议的集合，它们共同实现了网络数据传输。其中TCP协议是面向连接的协议，可以保证数据的可靠传输。而IP协议则是一种无连接的协议，仅仅负责数据包的传输。在TCP/IP协议中，应用层通过Socket接口与TCP协议建立连接，在进行数据传输时，TCP将数据分割成若干个数据包并进行传输，接收方收到数据包后会进行重新组装。

二、Android TCP通信代码示例

下面以一个简单的Android客户端和服务器端通信为例，演示如何实现TCP通信。

1. 服务端代码


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 Server {

    private ServerSocket serverSocket;

    public Server(int port) {
        try {
            serverSocket = new ServerSocket(port);
            System.out.println("Server started");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void listen() {
        while (true) {
            try {
                Socket socket = serverSocket.accept();
                System.out.println("Client connected");
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
                String message = "";
                while (!message.equals("exit")) {
                    message = in.readLine();
                    System.out.println("Received message: " + message);
                    out.println("Server received message: " + message);
                }
                socket.close();
                System.out.println("Client disconnected");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) {
        Server server = new Server(8080);
        server.listen();
    }
}

2. 客户端代码


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

public class Client {

    public static void main(String[] args) {
        try {
            Socket socket = new Socket("localhost", 8080);
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
            BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
            String message = "";
            while (!message.equals("exit")) {
                message = input.readLine();
                out.println(message);
                String response = in.readLine();
                System.out.println("Received message: " + response);
            }
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}