将数据包广播到不在java中工作的客户端

我有多个发送器配置为当它们接收从服务器通过本地端口5255发送的广播数据包时发回响应，远程端口5252包含字符串“AST show me \ 0”（如发送者手册中所述）。 这应该可以帮助我扫描本地网络中的所有发射器。 我已经实现了一个服务器端代码来广播该字符串消息，但是当我运行代码时，它在以下行代码中有一个错误：

socket.receive(packet1); 

我真的不知道我在这段代码中做错了什么或遗漏了什么。 任何帮助将不胜感激。

注意：如果有帮助：发射器的IP地址是192.168.40。*; 服务器IP地址为192.168.40.254。

提前致谢 ！！

这是代码：

 package socket_test; import java.io.*; import java.net.*; public class Server_UDP_Broadcast { //@SuppressWarnings("null") public static void main(String[] args) { // TODO Auto-generated method stub DatagramSocket socket = null; try{ socket = new DatagramSocket(5255); socket.setSoTimeout(10000); String str = "AST show me\0"; byte[] buf = new byte[256]; buf = str.getBytes(); InetAddress group = InetAddress.getByName("255.255.255.255"); DatagramPacket packet; packet = new DatagramPacket(buf, buf.length, group, 5252); socket.send(packet); // receive answer and display byte[] buf1 = new byte[1024]; DatagramPacket packet1 = new DatagramPacket(buf1, buf1.length); socket.receive(packet1); String received = new String(packet1.getData(), 0, packet1.getLength()); System.out.println("Answer from I-Lite :: " + received); } catch (IOException e) { e.printStackTrace(); } } 

}

以下是错误：

 java.net.SocketTimeoutException: Receive timed out at java.net.DualStackPlainDatagramSocketImpl.socketReceiveOrPeekData (Native Method) at java.net.DualStackPlainDatagramSocketImpl.receive0(Unknown Source) at java.net.AbstractPlainDatagramSocketImpl.receive(Unknown Source) at java.net.DatagramSocket.receive(Unknown Source) at socket_test.Server_UDP_Broadcast.main(Server_UDP_Broadcast.java:31) 

以下是wireshark的截图：

捕获数据包的详细信息

WireShark的屏幕截图