java双向文件传输

Java实现双向文件传输可以使用Socket编程，其中服务器端和客户端都需要编写代码实现文件传输。以下是一个简单的示例代码：

服务器端：

import java.io.*;
import java.net.*;

public class Server {
    public static void main(String[] args) {
        try {
            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();
            System.out.println("客户端已连接...");

            // 接收客户端发送的文件
            InputStream is = socket.getInputStream();
            FileOutputStream fos = new FileOutputStream("server_receive.txt");
            byte[] buffer = new byte[1024];
            int len;
            while ((len = is.read(buffer)) != -1) {
                fos.write(buffer, 0, len);
            }
            fos.close();
            is.close();
            System.out.println("文件接收成功！");

            // 发送文件给客户端
            OutputStream os = socket.getOutputStream();
            FileInputStream fis = new FileInputStream("server_send.txt");
            buffer = new byte[1024];
            while ((len = fis.read(buffer)) != -1) {
                os.write(buffer, 0, len);
            }
            fis.close();
            os.close();
            System.out.println("文件发送成功！");

            socket.close();
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

客户端：

import java.io.*;
import java.net.*;

public class Client {
    public static void main(String[] args) {
        try {
            Socket socket = new Socket("localhost", 8888);

            // 发送文件给服务器
            OutputStream os = socket.getOutputStream();
            FileInputStream fis = new FileInputStream("client_send.txt");
            byte[] buffer = new byte[1024];
            int len;
            while ((len = fis.read(buffer)) != -1) {
                os.write(buffer, 0, len);
            }
            fis.close();
            os.close();
            System.out.println("文件发送成功！");

            // 接收服务器发送的文件
            InputStream is = socket.getInputStream();
            FileOutputStream fos = new FileOutputStream("client_receive.txt");
            buffer = new byte[1024];
            while ((len = is.read(buffer)) != -1) {
                fos.write(buffer, 0, len);
            }
            fos.close();
            is.close();
            System.out.println("文件接收成功！");

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

注意：以上代码只是一个简单的示例，没有进行错误处理和异常处理，请在实际应用中加强代码的健壮性。