package main; 


import java.io.DataInputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
 
public class JavaSocketApplication {
 
 public static void main(String[] args) throws Exception {
 JavaSocketApplication receiver = new JavaSocketApplication(8700);
 receiver.receive();
 }
 
 private final ServerSocket serverSocket;
 
 public JavaSocketApplication(int port) throws IOException {
 serverSocket = new ServerSocket(port);
 }
 
 private void receive() throws IOException {
 System.out.println("等待客户端连接...");
 Socket socket = serverSocket.accept();
 try (DataInputStream dis = new DataInputStream(socket.getInputStream())) {
 byte[] bytes = new byte[1024]; // 假设发送的字节数不超过 1024 个
 int size = dis.read(bytes); // size 是读取到的字节数
 
 String hex = bytesToHex(bytes, 0, size);
 System.out.println("接收到的byte数组的十六进制:" + hex);
 }
 }
 
 /**
 * 将 byte 数组转化为十六进制字符串
 *
 * @param bytes byte[] 数组
 * @param begin 起始位置
 * @param end 结束位置
 * @return byte 数组的十六进制字符串表示
 */
 private String bytesToHex(byte[] bytes, int begin, int end) {
 StringBuilder hexBuilder = new StringBuilder(2 * (end - begin));
 for (int i = begin; i < end; i++) {
 hexBuilder.append(Character.forDigit((bytes[i] & 0xF0) >> 4, 16)); // 转化高四位
 hexBuilder.append(Character.forDigit((bytes[i] & 0x0F) >> 0, 16)); // 转化低四位
 hexBuilder.append(' '); // 加一个空格将每个字节分隔开
 }
 return hexBuilder.toString().toUpperCase();
 }
 
}