Usb4java read and write

[Stel Al]

import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;

import javax.swing.JOptionPane;

import org.usb4java.BufferUtils;
import org.usb4java.Context;
import org.usb4java.Device;
import org.usb4java.DeviceDescriptor;
import org.usb4java.DeviceHandle;
import org.usb4java.DeviceList;
import org.usb4java.LibUsb;
import org.usb4java.LibUsbException;
 
public class Test {
 private static byte endpoint;
   // private static final byte IN_ENDPOINT = 0;
private static Device device;
private static   Context context = new Context();
private static DeviceHandle handle;

    public static void main(String[] args) {
 
        // Create the libusb context
    LibUsb.init(null);
        findDevice(context, (short) (0x046D), (short) (0xC016));
        // Deinitialize the libusb context
        LibUsb.exit(context);
       
    }
 
    public static void findDevice(Context context, short vendorId, short productId) {
 
        // Initialize the libusb context
        int result = LibUsb.init(context);
        if (result < 0) {
            throw new LibUsbException("Unable to initialize libusb", result);
        }
 
        // Read the USB device list
        DeviceList list = new DeviceList();
        result = LibUsb.getDeviceList(context, list);
        if (result < 0) {
            throw new LibUsbException("Unable to get device list", result);
        }
 
        try {
            // Iterate over all devices and list them
            for (Device device : list) {
 
                int address = LibUsb.getDeviceAddress(device);
                int busNumber = LibUsb.getBusNumber(device);
                DeviceDescriptor descriptor = new DeviceDescriptor();
                result = LibUsb.getDeviceDescriptor(device, descriptor);
 
                if (result < 0) {
                    throw new LibUsbException(
                            "Unable to read device descriptor", result);
                }
                System.out.format(
                        "Bus %03d, Device %03d: Vendor %04x, Product %04x%n",
                        busNumber, address, descriptor.idVendor(),
                        descriptor.idProduct());
 
                if (result != LibUsb.SUCCESS) {
                    throw new LibUsbException("Unable to read device descriptor", result);
                }
                if (descriptor.idVendor() == vendorId && descriptor.idProduct() == productId) {
 
                    System.out.println("Device Found");
                    getDeviceHandle(device);
                    LibUsb.claimInterface(handle, 0);
                }
 
            }
        } finally {
            // Ensure the allocated device list is freed
            LibUsb.freeDeviceList(list, true);
        }
    }
 
    public static void getDeviceHandle(Device device) {
         endpoint = (byte)LibUsb.getDeviceAddress(device);
         
   
         
         
          handle = new DeviceHandle();
          JOptionPane.showMessageDialog(null, "endpoint="+endpoint);
         
        int result = LibUsb.open(device, handle);
       
 
        if (result != LibUsb.SUCCESS) {
            throw new LibUsbException("Unable to open USB device", result);
        }
 
        try {
            // Use device handle here
            claimDevice(handle, 0);
         
           
        } finally {
            LibUsb.close(handle);
        }
    }
 
    public static void claimDevice(DeviceHandle handle, int interfaceNumber) {
      
       
        int result = LibUsb.claimInterface(handle, interfaceNumber);
 
        if (result != LibUsb.SUCCESS) {
            throw new LibUsbException("Unable to claim interface", result);
        }
        try {
       
            System.out.println("Device Claimed");
            //sendData(handle);
           // read(handle,1000);
            JOptionPane.showMessageDialog(null, "interface="+interfaceNumber);
          // sendData(handle);
            read(handle, 2048);
           
           
           
           
           
           
        } finally {
            result = LibUsb.releaseInterface(handle, interfaceNumber);
            if (result != LibUsb.SUCCESS) {
                throw new LibUsbException("Unable to release interface", result);
            }
        }
    }
 
    @SuppressWarnings("unused")
   
   
   
   
   
 
   
    public static void sendData(DeviceHandle handle) {
 
    char[] initEP = new char[]{0x1b, '@'};
    char[] cutPaper = new char[]{0x1d, 'V', 1};
 
      String initStr = new String(initEP);
      String cutStr = new String(cutPaper);
        String text = "blabla \n\n\n";
 
        ByteBuffer buffer = ByteBuffer.allocateDirect(8);
        buffer.put(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 });
        // SEND INIT BYTE
       int transfered = LibUsb.controlTransfer(handle,
             (byte) (LibUsb.REQUEST_TYPE_CLASS | LibUsb.RECIPIENT_INTERFACE),
             (byte) 0x01, (short) 2, (short) 1, buffer, 5000);
 
     if (transfered < 0) {
           throw new LibUsbException("Control transfer failed", transfered);
        }
 
        // SENDT TEXT
        buffer = ByteBuffer.wrap(text.getBytes());
       
       transfered = LibUsb.controlTransfer(handle,
                (byte) (LibUsb.REQUEST_TYPE_CLASS | LibUsb.RECIPIENT_INTERFACE),
                (byte) 0x01, (short) 2, (short) 1, buffer, 5000);
 
        if (transfered < 0) {
            throw new LibUsbException("Control transfer failed", transfered);
        }
       
       // SENDT CUT BYTE
        buffer = ByteBuffer.wrap(text.getBytes());
       
        transfered = LibUsb.controlTransfer(handle,
                (byte) (LibUsb.REQUEST_TYPE_CLASS | LibUsb.RECIPIENT_INTERFACE),
                (byte) 0x09, (short) 2, (short) 1, buffer, 5000);
 
        if (transfered < 0) {
            throw new LibUsbException("Control transfer failed", transfered);
        }
        System.out.println(transfered + " bytes sent");
    }
   
    public static ByteBuffer read(DeviceHandle handle, int size)
    {
       
       
         ByteBuffer buffer = BufferUtils.allocateByteBuffer(size).order(ByteOrder.LITTLE_ENDIAN);
         IntBuffer transferred = BufferUtils.allocateIntBuffer();

       // IntBuffer transferred = BufferUtils.allocateIntBuffer();
        long TIMEOUT = 5000;
       
      
        JOptionPane.showMessageDialog(null, "endpoint_in="+ LibUsb.ENDPOINT_IN);
        JOptionPane.showMessageDialog(null, "endpoint_out="+ LibUsb.ENDPOINT_OUT);
        JOptionPane.showMessageDialog(null, "handle="+handle);
       
        int result = LibUsb.bulkTransfer(handle, (byte)LibUsb.ENDPOINT_IN, buffer,
            transferred, TIMEOUT);
       
        JOptionPane.showMessageDialog(null, result);
       
        if (result != LibUsb.SUCCESS)
        {
            throw new LibUsbException("Unable to read data", result);
        }
        else{System.out.println(transferred.get() + " bytes read from device");
     
        }
   
      
        return buffer;
         }
}


I get USB error 5: Unable to read data: Entity not found

can anybody help???

[Firat Yuzbasioglu]

Hi it is all about driver installation problem. Try, zadig tool, install your driver. https://zadig.akeo.ie/