我尝试通过usb4java api从usb设备读取但是我收到错误： USB错误5：无法读取数据：未找到实体 有谁能够帮我？ 需要注意的是，endpoint_in我从LibUsb.ENDPOINT_IN得到它并且我将它传递给读取功能声称找到设备但是我无法继续从设备读取。
My code is given below:
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);
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)-128, 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;
}
}
该设备是usb鼠标的问题吗？
In order to write i use this code (the write function that I call in my main function):
public static ByteBuffer write（DeviceHandle handle，int size） {ByteBuffer buffer = ByteBuffer.allocateDirect（8）; buffer.put（new byte [] {'p'}）;
String text="p";
//ByteBuffer buffer = ByteBuffer.wrap(text.getBytes());
IntBuffer transferred = BufferUtils.allocateIntBuffer();
long TIMEOUT = 5000;
int result = LibUsb.bulkTransfer(handle, (byte) 0x01, buffer,
transferred, TIMEOUT);
if (result != LibUsb.SUCCESS)
{
throw new LibUsbException("Unable to write data", result);
}
else{System.out.println(transferred.get() + " bytes written to the device");
}
return buffer;
}
但我收到USB错误5：无法写入数据：未找到实体
Why the entity is not found since I use endpoint 0x01...
答案 0 :(得分：0)