Thread: Whats wrong with my code??

Hi, can any one help me whats wrong with my code? the file location is that of a usb device which has been connected to my computer system. it should in theory display the name, driver and class of the device, however i keep gettin "null" error messages. any help would be greatly appriciated.

import java.io.*;
import javax.swing.JOptionPane;
 
public class USBDevices
{
	// Allows the registry to be viewed and opens specific value by creating strings
	private static final String REGQUERY = "reg query";
	private static final String REG_SZ = "REG_SZ";
 
	// Sets the location of the folder found in the registry as a string for Device Name
	private static final String FriendlyName = REGQUERY +
	"\"HKLM\\SYSTEM\\CurrentControlSet\\Enum\\USBSTOR\\Disk&Ven_HTC&Prod_Android_Phone&Rev_0100\\HT091PL05241&0\" /v FriendlyName";
 
 
	// Sets the location of the folder found in the registry as a string for Device Driver
	private static final String DeviceDriver = REGQUERY +
	"\"HKLM\\SYSTEM\\CurrentControlSet\\Enum\\USBSTOR\\Disk&Ven_HTC&Prod_Android_Phone&Rev_0100\\HT091PL05241&0\" /v Driver";
 
 
	// Sets the location of the folder found in the registry as a string for Device Type
	private static final String Class = REGQUERY +
	"\"HKLM\\SYSTEM\\CurrentControlSet\\Enum\\USBSTOR\\Disk&Ven_HTC&Prod_Android_Phone&Rev_0100\\HT091PL05241&0\" /v Class";
 
 
	// This sets a string to allow the data retrieved to have a name attatched to it
	public static String getDeviceFriendlyName()
	{
		try
		{
			// This is the process what will open up the registry and retrive the data found for the device name then
			// save it within the string called getDeviceFriendlyName
			Process process = Runtime.getRuntime().exec(FriendlyName);
      		StreamReader reader = new StreamReader(process.getInputStream());
 
      		reader.start();
      		process.waitFor();
      		reader.join();
 
     		String result = reader.getResult();
     	 	int p = result.indexOf(REG_SZ);
 
			// If no data is retrived it will save the string as null
      		if (p == -1)
         	return null;
 
      		return result.substring(p + REG_SZ.length()).trim();
		}
 
		// This will allow an exception to be caught and saved as null
		catch (Exception e)
		{
			return null;
		}
 
	}
 
		// This sets a string to allow the data retrieved to have a name attatched to it
	public static String getDeviceDriver()
	{
		try
		{
			// This is the process what will open up the registry and retrive the data found for the device name then
			// save it within the string called getDeviceDriver
			Process process = Runtime.getRuntime().exec(DeviceDriver);
      		StreamReader reader = new StreamReader(process.getInputStream());
 
      		reader.start();
      		process.waitFor();
      		reader.join();
 
     		String result = reader.getResult();
     	 	int p = result.indexOf(REG_SZ);
 
			// If no data is retrived it will save the string as null
      		if (p == -1)
         	return null;
 
      		return result.substring(p + REG_SZ.length()).trim();
		}
 
		// This will allow an exception to be caught and saved as null
		catch (Exception e)
		{
			return null;
		}
 
	}
 
			// This sets a string to allow the data retrieved to have a name attatched to it
	public static String getDeviceClass()
	{
		try
		{
			// This is the process what will open up the registry and retrive the data found for the device name then
			// save it within the string called getDeviceClass
			Process process = Runtime.getRuntime().exec(Class);
      		StreamReader reader = new StreamReader(process.getInputStream());
 
      		reader.start();
      		process.waitFor();
      		reader.join();
 
     		String result = reader.getResult();
     	 	int p = result.indexOf(REG_SZ);
 
			// If no data is retrived it will save the string as null
      		if (p == -1)
         	return null;
 
      		return result.substring(p + REG_SZ.length()).trim();
		}
 
		// This will allow an exception to be caught and saved as null
		catch (Exception e)
		{
			return null;
		}
 
	}
 
	//This creates a stream reader to read the values, it then places it in to a tempory string to be used
	 static class StreamReader extends Thread
	 {
	 	private InputStream is;
    	private StringWriter sw;
 
    	StreamReader(InputStream is)
 
    	{
    		this.is = is;
      		sw = new StringWriter();
    	}
 
    public void run()
    {
    	try
    	{
    		int c;
        	while ((c = is.read()) != -1)
        	sw.write(c);
    	}
 
    	catch (IOException e)
    	{
    		;
    	}
 
    }
 
    // This puts the data found in the tempory string in to a fixed string
     String getResult()
     	{
     		return sw.toString();
     	}
	 }
 
	 public static void main(String s[])
 
 
	 	{
	 		// This is what outputs the data in to a message display box
 
			String Line1 = "Name of Device         " + "Device Driver         " + "Type of Device         " + "\n";
			String Line2 = getDeviceFriendlyName() + "  " + getDeviceDriver() + "  " + getDeviceClass();
 
 
    		JOptionPane.showMessageDialog (null, Line1 + Line2, "USB Devices",JOptionPane.PLAIN_MESSAGE);
 
 
 
	 	}
}