Java网络服务扫描程序

我正在尝试编写一个类，它将扫描本地网络以查找将要运行的服务。

问题是如果地址没有激活（没有回复），它会挂起5秒以上，这是不好的。

我想在几秒钟内完成扫描。 有人可以提供一些建议吗？

我的代码部分如下

int port = 1338; PrintWriter out = null; BufferedReader in = null; for (int i = 1; i < 254; i++){ try { System.out.println(iIPv4+i); Socket kkSocket = null; kkSocket = new Socket(iIPv4+i, port); kkSocket.setKeepAlive(false); kkSocket.setSoTimeout(5); kkSocket.setTcpNoDelay(false); out = new PrintWriter(kkSocket.getOutputStream(), true); in = new BufferedReader(new InputStreamReader(kkSocket.getInputStream())); out.println("Scanning!"); String fromServer; while ((fromServer = in.readLine()) != null) { System.out.println("Server: " + fromServer); if (fromServer.equals("Server here!")) break; } } catch (UnknownHostException e) { } catch (IOException e) { } } 

谢谢你的答案！ 这是我为其他任何人寻找此代码的代码！

  for (int i = 1; i < 254; i++){ try { System.out.println(iIPv4+i); Socket mySocket = new Socket(); SocketAddress address = new InetSocketAddress(iIPv4+i, port); mySocket.connect(address, 5); out = new PrintWriter(mySocket.getOutputStream(), true); in = new BufferedReader(new InputStreamReader(mySocket.getInputStream())); out.println("Scanning!"); String fromServer; while ((fromServer = in.readLine()) != null) { System.out.println("Server: " + fromServer); if (fromServer.equals("Server here!")) break; } } catch (UnknownHostException e) { } catch (IOException e) { } } 

Answer 1

您可以尝试通过调用Socket.connect( address, timeout )显式连接到服务器。

  Socket kkSocket = new Socket(); kkSocket.bind( null )/ // bind socket to random local address, but you might not need to do this kkSocket.connect( new InetSocketAddress(iIPv4+i, port), 500 ); //timeout is in milliseconds 

Answer 2

您可以使用noarg构造函数Socket()创建一个未连接的套接字，然后使用较小的超时值调用connect(SocketAddress endpoint, int timeout) 。

 Socket socket = new Socket(); InetSocketAddress endpoint = new InetSocketAddress("localhost", 80); int timeout = 1; socket.connect(endpoint, timeout);