demo_server in java?

0xfa1c0
Posts: 7
Joined: Sat Dec 10, 2016 11:48 pm

demo_server in java?

Postby 0xfa1c0 » Sun Jan 01, 2017 7:06 pm

Anyone has implemented a demo_server in java?

I have done a scratch following this example: http://tutorials.jenkov.com/java-multithreaded-servers/multithreaded-server.html

this is my worker thread implementation:

Code: Select all

public class TcpSocketRunnable implements Runnable {
    protected Socket mClientSocket = null;
   
    public interface TcpSocketListener {
        public void onPacket(byte[] packet, int length);
        public String getResponse(String sourceMacAddress);
    }
   
    private TcpSocketListener mListener = null;
   
    public void setListener(TcpSocketListener listener) {
       mListener = listener;
    }
   
    public TcpSocketRunnable(Socket clientSocket) {
        this.mClientSocket = clientSocket;
    }
   
    private byte[] prepareReplyToPacket(byte[] pckt, String response) {
       byte[] srcMac = new byte[6];
       byte[] payloadPacket = response.getBytes();
      int responsePacketLength = 16 + payloadPacket.length;
      byte[] responsePacket = new byte[responsePacketLength];
      /* Build response packet */
      System.arraycopy(pckt, 10, srcMac, 0, 6);
      System.arraycopy(pckt, 0, responsePacket, 0, 2); /* Copy ver, o, flags, proto */
      responsePacket[2] = (byte)(responsePacketLength);
      responsePacket[3] = (byte)(responsePacketLength>>8);
      System.arraycopy(pckt, 4, responsePacket, 10, 6); /* Copy dst address into src field */
      System.arraycopy(srcMac, 0, responsePacket, 4, 6);  /* Copy src address into dst field */
        System.arraycopy(payloadPacket,0,responsePacket,16,payloadPacket.length);
        return responsePacket;
    }
   
    public void run() {
       InputStream input = null;
       OutputStream output = null;
        try {
           System.out.println("socket open!");
           byte[] buffer = new byte[1024];
           byte[] tmp;
           int len;
           int read_len;
            input  = new BufferedInputStream(mClientSocket.getInputStream());
            output = new BufferedOutputStream(mClientSocket.getOutputStream());
            /* Read first 4 packet byte */
            read_len = input.read(buffer, 0, 4);
            /* The lenght of the whole packet is in the last two byte */
            len = (buffer[3]<<8) + buffer[2];
           
            if (len <= 0) {
               return;
            }
            /* Check if buffer len can store the packet */
            if (len > 1024) {
               tmp = new byte[len];
               /* Copy header in the buffer */
               System.arraycopy(buffer, 0, tmp, 0, 4);
               buffer = tmp;
            }
            /* Read the whole packet less the 4 byte header */
            read_len = input.read(buffer, 4, len-4);
           
            if (mListener != null && read_len == (len-4)) {
               byte[] srcMac = new byte[6];
               String srcMacString, response;
               System.out.println("Received packet len: "+(read_len+4));

               /* Call listener's onPacket */
               mListener.onPacket(buffer, len);
               
               /* Check if we have to send a response */
               System.arraycopy(buffer, 10, srcMac, 0, 6);
               srcMacString = DatatypeConverter.printHexBinary(srcMac);
               response = mListener.getResponse(srcMacString);
               if (response != null) {
                  byte[] responsePacket = prepareReplyToPacket(buffer, response);
                  output.write(responsePacket);
               }
            }
        } catch (IOException e) {
            //report exception somewhere.
            //e.printStackTrace();
        } finally {
           try {
              if (output != null) {
                 output.close();
              }
            if (input != null) {
               input.close();
            }
               this.mClientSocket.close();
               System.out.println("socket close!");
         } catch (IOException e) {}
           mClientSocket = null;
           mListener = null;
        }
    }
}


but it doesn't work well like the python server example. Anyone can help?

ESP_Xutao
Posts: 134
Joined: Tue Sep 27, 2016 5:42 pm

Re: demo_server in java?

Postby ESP_Xutao » Tue Feb 14, 2017 10:29 am

hi:
you can creat a client to connect Demo_server,You should be sure that your server is connectable.About more this question,you can thought search engine.

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