编译具有异常错误/警告的Java USB程序 [英] Compiling a Java USB program with unusual errors/warnings
问题描述
我正在开发USB读取Java程序,以获取连接的USB设备的名称。这是我写的代码:
I was developing a USB reading Java program to get the name of the attached USB device. This is the code I wrote:
import java.io.UnsupportedEncodingException;
import java.util.List;
import javax.usb.*;
import javax.usb.UsbDevice;
import javax.usb.UsbDisconnectedException;
import javax.usb.UsbException;
import javax.usb.UsbHostManager;
import javax.usb.UsbHub;
import javax.usb.UsbServices;
public class ListUsbDevices {
public static void main(String[] args) throws SecurityException, UsbException, UnsupportedEncodingException, UsbDisconnectedException {
UsbServices services = UsbHostManager.getUsbServices();
UsbHub rootHub = services.getRootUsbHub();
List<UsbDevice> devices = rootHub.getAttachedUsbDevices();
if (devices.size() > 0) {
System.out.println("USB devices found.");
} else {
System.out.println("No USB devices found.");
}
for (UsbDevice device : devices) {
System.out.println("\tProduct String " + device.getProductString());
System.out.println("\tManufacturer String " + device.getManufacturerString());
System.out.println("\tSerial Number " + device.getSerialNumberString());
}
}
}
当我编译该程序时,它显示以下警告:
When I compile this program, it shows this warning:
Note: ListUsbDevices.java uses unchecked or unsafe operations.
Recompile with -Xlint:unchecked for details.
我用 -Xlint重新编译:未选中
,它显示以下内容:
I recompile with -Xlint:unchecked
, and it shows this:
ListUsbDevices.java:21: warning: [unchecked] unchecked conversion
found : java.util.L
required: java.util.List<javax.usb.UsbDevice>
List<UsbDevice> devices = rootHub.getAttachedUsbDevices();
^.
但是创建了类文件。
运行此程序时,出现以下异常:
When I run this program, I get this exception:
Exception in thread "main" javax.usb.UsbException: Properties file
javax.usb.properties not found.
如何解决此问题?如何在Mac中设置属性文件?我已经用以下方法设置了CLASSPATH:
How do I solve this problem? How do I set the properties file in Mac? I had set the CLASSPATH with this:
export CLASSPATH=.:/Users/sakkisetty/Documents/jsr80-1.0.1.jar
但我不确定是否可行。
But I'm not sure that worked. Any pointers would be appreciated.
推荐答案
属性文件通常是本机包的一部分。我什至不知道OSX的实现。
The properties file is usually part of the native package. I wasn't even aware of an implementation for OSX.
有关如何为Linux设置它的示例,请参见 javax.usb常见问题解答。
An example of how to set it for Linux is available at javax.usb FAQ.
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