I am trying to connect with a Biometric Fingerprint Attendance Device using a Java program. The device I am using is a Biocom Fingerprint attendance system. However, I am search and reading about that and I see the SDK could used which based on device type (which hard, not logical, moreover, it is not global solution!)

I research for a global standard on how to connect, send and retrieve data with a Fingerprint Device which again I wasn't lucky enough to find a clear solution. Currently, I tried to connect with the device by creating a `Socket` object (through Ethernet port) but also not executed with me. This open infinite loop problems on my head.

* Is there any general, standard way to connect, send and retrieve data from such device using Java?
* Can a `Socket` be considered as a solution for such problem?
* If yes, what is wrong in my code below? What additional things more than the host IP and port number are needed to connect with the device?

The Socket code that used:

```
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class Requester {
Socket requestSocket;
ObjectOutputStream out;
ObjectInputStream in;
String message;

Requester() {
}

void run() throws IOException {
    try {
        // 1. creating a socket to connect to the server
        requestSocket = new Socket("192.168.0.19", 4370);
        System.out.println("Connected to given host in port 4370");
        // 2. get Input and Output streams
        in = new ObjectInputStream(requestSocket.getInputStream());
        // 3: Communicating with the server
        String line;
        while (true) {
            line = in.readLine();
            if (line != null) {
                System.out.println(line);
            }
        }
    } catch (UnknownHostException unknownHost) {
        System.err.println("You are trying to connect to an unknown host!");

    } catch (IOException ioException) {
        ioException.printStackTrace();

    } catch (Exception Exception) {
        Exception.printStackTrace();

    } finally {
        in.close();
        requestSocket.close();
    }
}

void sendMessage(String msg) {
    try {
        out.writeObject(msg);
        out.flush();
        System.out.println("client: " + msg);

    } catch (IOException ioException) {
        ioException.printStackTrace();
    }
}

public static void main(String args[]) throws IOException {
    Requester client = new Requester();
    client.run();
}
}

```

This image may give more details: 

![](https://i.stack.imgur.com/hj74q.jpg)