我正在尝试使用 jUSB 库通过 USB 到串行电缆发送数据。我在 Windows 上的 NetBeans IDE 中进行编码。
消息背后的问题是什么：以下代码中的“USB Host support is available”：
package usb.core;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import usb.core.*;
public class Main {
public static void main(String[] args) throws IOException {
try {
// Bootstrap by getting the USB Host from the HostFactory.
Host host = HostFactory.getHost();
// Obtain a list of the USB buses available on the Host.
Bus[] bus = host.getBusses();
int total_bus = bus.length;
System.out.println(total_bus);
// Traverse through all the USB buses.
for (int i = 0; i < total_bus; i++) {
// Access the root hub on the USB bus and obtain the
// number of USB ports available on the root hub.
Device root = bus[i].getRootHub();
int total_port = root.getNumPorts();
// Traverse through all the USB ports available on the
// root hub. It should be mentioned that the numbering
// starts from 1, not 0.
for (int j = 1; j <= total_port; j++) {
// Obtain the Device connected to the port.
Device device = root.getChild(j);
if (device != null) {
// USB device available, do something here.
// Obtain the current Configuration of the device
// and the number of interfaces available under the
// current Configuration.
Configuration config = device.getConfiguration();
int total_interface = config.getNumInterfaces();
// Traverse through the Interfaces
for (int k = 0; k < total_interface; k++) {
// Access the current Interface and obtain the
// number of endpoints available on the Interface
Interface itf = config.getInterface(k, 0);
int total_ep = itf.getNumEndpoints();
// Traverse through all the endpoints.
for (int l = 0; l < total_ep; l++) {
// Access the endpoint and
// obtain its I/O type
Endpoint ep = itf.getEndpoint(l);
String io_type = ep.getType();
boolean input = ep.isInput();
// If the endpoint is an input endpoint,
// obtain its InputStream and read in data.
if (input) {
InputStream in;
in = ep.getInputStream();
// Read in data here
in.close();
}
else {
// If the Endpoint is an output Endpoint,
// obtain its OutputStream and
// write out data.
OutputStream out;
out = ep.getOutputStream();
// Write out data here.
out.close();
}
}
}
}
}
}
}
catch (Exception e) {
System.out.println(e.getMessage());
}
}
}