Portable Device Path on Windows

问题:

I've actually got an Windows/Java Question. I've got a plugged-in device which I want to access via Java. Normally you can access an e.g. USB-Stick via the Drive letter... but this tablet is displayed by Windows as a "Portable Device"... which means, that the Path is something like "Computer\Archos 5S" and there is no Drive letter.

I want to access a file on this device via Java, but I am not able to figure out the correct path to it. There is a similar question out there, but without a productive answer. Or is there another way to access this device via Java?

---

Actually I've not solved this problem... I am still not able to access such a device via java.

At the moment I am trying to access a windows ShellFolder in Java. A Shellfolder like: "Shell:::{35786D3C-B075-49b9-88DD-029876E11C01}"

Is this possible with Java? Recently I uncovered the sun.awt class "ShellFolder"... is this the wanted feature?

thanks for your help Ripei

回答1:

The solution to above problem using JMTP library on https://code.google.com/p/jmtp/

Here is my code

package jmtp;

import be.derycke.pieter.com.COMException;
import be.derycke.pieter.com.Guid;
import java.io.*;
import java.math.BigInteger;
import jmtp.PortableDevice;
import jmtp.*;

public class Jmtp {

    public static void main(String[] args) {
        PortableDeviceManager manager = new PortableDeviceManager();
        PortableDevice device = manager.getDevices()[0];
        // Connect to my mp3-player
        device.open();

        System.out.println(device.getModel());

        System.out.println("---------------");

        // Iterate over deviceObjects
        for (PortableDeviceObject object : device.getRootObjects()) {
            // If the object is a storage object
            if (object instanceof PortableDeviceStorageObject) {
                PortableDeviceStorageObject storage = (PortableDeviceStorageObject) object;

                for (PortableDeviceObject o2 : storage.getChildObjects()) {
//                    
//                        BigInteger bigInteger1 = new BigInteger("123456789");
//                        File file = new File("c:/JavaAppletSigningGuide.pdf");
//                        try {
//                            storage.addAudioObject(file, "jj", "jj", bigInteger1);
//                        } catch (Exception e) {
//                            //System.out.println("Exception e = " + e);
//                        }
//                    

                    System.out.println(o2.getOriginalFileName());
                }
            }
        }

        manager.getDevices()[0].close();

    }
}

Do not forget add jmtp.dll files (that comes up with jmtp download) as a native library. For more info, see my answer on Including Native Library in Netbeans.

回答2:

Like *nix systems, all devices (including drives) have paths that are part of a common root, this is normally hidden from users because they use the drive letters which are aliases to these fundamental paths, but you can also use full device paths by prefixing the path with "\\.\"

For instance, on my machine D: translates as "\Device\HarddiskVolume1" and can be accessed by passing "\\.\HarddiskVolume1" to CreateFile.

So the path to your device is probably "\\.\Archos 5s".

回答3:

you can always download and install the Windows mobile developer Powertoys (http://www.microsoft.com/download/en/details.aspx?id=10601) and copy from and to the device using the command line utility cecopy, which you can run from any programming language. There are other options there too, but it's most targeted at .Net