Java網絡服務掃描器

Question

我想寫一個類，將掃描本地網絡的服務將運行。

問題是，如果地址沒有激活（無回覆），它會在其上掛起5秒以上，這是不好的。

我想在幾秒鐘內完成此掃描。任何人都可以提供建議嗎？

我的代碼部分低於

 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) { 

     } 
    } 

感謝您的答案！這是我的代碼給其他人尋找這個！

 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

您可以嘗試通過調用Socket.connect(address, timeout)明確地連接到服務器。

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構造Socket()創建未連接套接字，然後調用connect(SocketAddress endpoint, int timeout)用小超時值。