import java.io.DataInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.net.ServerSocket;import java.net.Socket;public class Server {    public static void main(String[] args) {        System.out.println("--->server");        try {            ServerSocket server = new ServerSocket(4700);            Socket socket = server.accept();            DataInputStream dis = new DataInputStream(socket.getInputStream());            String type = dis.readUTF();            System.out.println("type: " + type);            // long len = dis.readLong();            // System.out.println("len: " + len);            byte[] buff = new byte[1024];            OutputStream os = new FileOutputStream("C:/Users/Administrator/Desktop/dts.jpg");            int len = -1;            while ((len = dis.read(buff)) != -1) {                os.write(buff, 0, len);            }            os.flush();            os.close();            dis.close();        } catch (IOException e) {            e.printStackTrace();        }        System.out.println("server--->");    }}

import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.InputStream;import java.net.Socket;public class Client {    public static void main(String args[]) {        try {            Socket socket = new Socket("127.0.0.1", 4700);            if (socket.isConnected()) {                System.out.println("isConnected");                DataOutputStream dos = new DataOutputStream(socket.getOutputStream());                dos.writeUTF("STREAM");                File file = new File("C:/Users/Administrator/Desktop/src.jpg");                // dos.writeLong(file.length());                byte[] buff = new byte[1024];                InputStream inputStream = new FileInputStream(file);                int len = -1;                while ((len = inputStream.read(buff)) != -1) {                    dos.write(buff, 0, len);                }                inputStream.close();                dos.flush();                dos.close();            }            // socket.close(); // 关闭Socket        } catch (Exception e) {            e.printStackTrace();        }    }}