Java Based Application to Map Network Drive

[Wraithier]

I have been working on this application for a couple weeks now and I'm running into a few problems I need some help/advice on. This application is supposed to make it easier (yes I know it's not hard) to map a network drive for users at my work who don't know how to do so. The users will choose from 3 potential usernames, will input the terminal name, and the password, which is the same for all will be input for them. All the variable are passing except for terminal name, whenever I run the program the entry for the terminal is being passed as null, a secondary problem is that currently the program tries to log on for all 3 usernames every time it is run. Any insight into what I am doing wrong would be greatly appreciated. I have posted my code below but obviously the usernames and password have been changed.

Code:

import java.awt.event.*;
import javax.swing.*;



public class MapDrive extends javax.swing.JFrame implements ActionListener, ItemListener {
    
    
    
    
    
    JFrame frame;
    public javax.swing.JTextField CompName; 
    public javax.swing.JButton ConnectButton;
    public javax.swing.JLabel LblCompName;
    public javax.swing.JLabel UsernameLbl;
    public javax.swing.JComboBox Username;
        
       
    static String usernames[] = {"Username1", "Username2", "Username3"}; //username
    static String password = ("password");  //password
    public String terminal; //The Compname
    public String username; //The Username
    
    
    
    public MapDrive() {       
        
        CompName = new javax.swing.JTextField();
        LblCompName = new javax.swing.JLabel();
        ConnectButton = new javax.swing.JButton();
        UsernameLbl = new javax.swing.JLabel();
        Username = new javax.swing.JComboBox(usernames);      
        Username.setSelectedIndex(-1);     
        Username.addActionListener(this);
        Username.addItemListener(this);        
        ConnectButton.addActionListener(this);
        
        this.setLocationRelativeTo(null);
        
        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setTitle("Map Network Drive");
        setName("Connect"); 
        setResizable(false);

        LblCompName.setText("Computer Name");

        ConnectButton.setText("Connect");

        UsernameLbl.setText("Username");       

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(55, Short.MAX_VALUE)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(LblCompName)
                    .addComponent(UsernameLbl))
                .addGap(42, 42, 42)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(Username, 0, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(CompName, javax.swing.GroupLayout.DEFAULT_SIZE, 104, Short.MAX_VALUE))
                .addGap(95, 95, 95))
            .addGroup(layout.createSequentialGroup()
                .addGap(138, 138, 138)
                .addComponent(ConnectButton)
                .addContainerGap(160, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap(47, Short.MAX_VALUE)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(LblCompName)
                    .addComponent(CompName, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(Username, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(UsernameLbl))
                .addGap(33, 33, 33)
                .addComponent(ConnectButton)
                .addGap(60, 60, 60))
        );

        pack();
        
    }     
   
   public void connect()
   {       
   Drives dr = new Drives();
   dr.scanDrives();
   dr.getFreeDrive();
   dr.run();   
   } 
      
   public void error()
   {             
       if (CompName.getText().isEmpty() == true)
       {
           JOptionPane.showMessageDialog(MapDrive.this, "Please Input a Computer Name","Error", JOptionPane.ERROR_MESSAGE);              
       }          
       else
       {
           terminal = CompName.getText(); 
       } 
       if (Username.getSelectedItem() == null)
       {
         JOptionPane.showMessageDialog(MapDrive.this, "Please Select a Username","Error", JOptionPane.ERROR_MESSAGE);  
       }
   } 
   
   public void setVariable()
   {
           terminal = CompName.getText();
   }
   
     
    public void actionPerformed(ActionEvent e) {        
        if (e.getSource() == ConnectButton) 
        { 
                    
          error();
          connect(); 
                 
          System.out.println(terminal); 
          System.out.println(username);
          System.out.println(password);
          
        }
        
    } 
    
    public void itemStateChanged( ItemEvent event ){
        if (event.getSource() == Username && event.getStateChange() == ItemEvent.SELECTED )
        {
            System.out.println( "Change:"+ Username.getSelectedItem() );
            username = (String) Username.getSelectedItem();
        }
    }
    
    
     public static void main(String args[]){ 
       MapDrive md = new MapDrive();
       md.setVisible(true);
    }
}

[Wraithier]

Here is the second .java file that contains most of the functions.

Code:

import java.io.*;
import java.util.Hashtable;

/**
* Maintains the list of available drives
*/
public class Drives implements Runnable
{
    
       	public String terminal;  // the terminal

	public boolean connected = false;  // tells if the conection to this terminal was possible or not
	        
	public boolean finished = false;  // tels if the thread has finished its work
        
	Hashtable drives = new Hashtable();        
	public Drives()
	{
		scanDrives();
	}

	/**
	* Scan the available drives with the "net use drive:" command
	*/
	public void scanDrives()
	{
		for (char ch='Z'; ch > 'F'; ch--)
		{
			String command = "net use " + ch + ":";
			String result = runCommand(command);

			// if found a free drive
			if (result.toUpperCase().indexOf(ch+":") == -1)
			{
				// add it to the list
                                //System.out.println(result.toUpperCase().indexOf(ch+":") == -1);
				drives.put(""+ch, new Boolean(true));
			}
		}
	}

	/**
	* @return the first free drive found
	*/
	public synchronized String getFreeDrive()
	{
		for (char ch='Z'; ch > 'F'; ch--)
		{
			Boolean res = (Boolean)(drives.get(""+ch));
			if (res != null && res.booleanValue())
			{
				// set the free drive found as busy
                            
                                
                                setBusyDrive(""+ch);				
				return ""+ch;
			}
		}

		return null;
	}

	/**
	* Sets this drive as free and available to be used
	*/
	public synchronized void setFreeDrive(String drive)
	{
		drives.put(drive, new Boolean(true));
	}

	/**
	* Sets the drive as busy and unavailable
	*/
	public synchronized void setBusyDrive(String drive)
	{
		drives.put(drive, new Boolean(false));
	}
        
        public void run()
	{
		System.out.println("Start thread ");

		String drive;

		while (true)
		{
			// get an available drive letter
                        
			drive = getFreeDrive();
			if (drive != null)
			{
				break;
			}

			// if no drive letter found, sleep for 5 sec then try again
			try
			{
				Thread.sleep(5000);
				System.out.println("Waiting for a free drive");
			} catch (InterruptedException e1)
			{
			}
		}

		// connect with the given list of passwords
		for (int i = 0; i < MapDrive.usernames.length; i++)
		{
			boolean success = mapDrive(drive, terminal, MapDrive.usernames[i],
			MapDrive.password);

			// if connection is successful, break
			if (success)
			{
				connected = true;
				break;
			}
		}

		// if no connection was possible, log and quit thread
		if (!connected)
		{
			System.out.println("Connection to " + terminal + " failed");
		}
		else // if connection possible
		{
			System.out.println("Connected to " + terminal);

		}

		// at the end disconnect the drive and free it
		disconnectDrive(drive);
		setFreeDrive(drive);

		// mark thread status as finished
		finished = true;
	}
        
     private void disconnectDrive(String drive)
	{
		String command = "net use " + drive + ": /delete";
		runCommand(command);
	}
                
      private boolean mapDrive(String drive, String terminal, String user,
	String pwd)
	{
		String command = null;

		if (user == null)
		{
			command = "net use " + drive + ": \\\\" + terminal + "\\C$ ";
		} else
		{
			command = "net use " + drive + ": \\\\" + terminal + "\\C$ " + pwd
			+ " /user:" + user;
		}
		return runCommandToBoolean(command);
	}
      
      public static String runCommand(String param)
	{
		try
		{
			StringBuffer sb = new StringBuffer();
			Process process = Runtime.getRuntime().exec(param);
			InputStream standardInput = process.getInputStream();
			BufferedReader br = new BufferedReader(new InputStreamReader(
			standardInput));
			InputStream standardError = process.getErrorStream();
			BufferedReader brError = new BufferedReader(new InputStreamReader(
			standardError));
			//OutputStream standardOutput = process.getOutputStream();
			String s;

			while ((s = br.readLine()) != null)
			{
				sb.append(s + "\n");
			}

			while ((s = brError.readLine()) != null)
			{
				sb.append(s + "\n");
			}

			standardInput.close();
			standardError.close();
			return sb.toString();
		}
		catch (Exception e)
		{
			System.out.println(e);
			return null;
		}
	}
      
      public static boolean runCommandToBoolean(String param)
	{
		try
		{
			boolean flag = false;
			System.out.println("Running: " + param);
			StringBuffer sb = new StringBuffer();
			Process process = Runtime.getRuntime().exec(param);
			InputStream standardInput = process.getInputStream();
			BufferedReader br = new BufferedReader(new InputStreamReader(
			standardInput));
			InputStream standardError = process.getErrorStream();
			BufferedReader brError = new BufferedReader(new InputStreamReader(
			standardError));
			//OutputStream standardOutput = process.getOutputStream();
			String s;
			while ((s = br.readLine()) != null)
			{
				sb.append(s + "\n");
				flag = true;
			}
			while ((s = brError.readLine()) != null)
			{
				sb.append(s + "\n");
				flag = false;
			}
			standardInput.close();
			standardError.close();
			return flag;
		} catch (Exception e)
		{
			System.out.println(e);
			return false;
		}
	}
}

[Norm]

Too much code to wade thru.
You need to use some debugging techniques.
Add some println() to the code to show where and what.
Run the code and look at the output to see what is happening.

[Wraithier]

I am using some println(), I know what is happening the variable I have for the terminal isn't being passed somehow and I can't figure out why. The println()s allow me to see what variable is the problem, but they don't allow me to see why. There really isn't that much code, I posted it all in case someone wants to copy/paste it and see what it does. A lot of the MapDrive stuff is the GUI a lot of the functionality is in the Drives file, I was just hoping someone could help me identify exactly what is wrong with my variable, because after hours I just don't see what it is.

[Norm]

"the variable I have for the terminal isn't being passed somehow"

Where is this happening? Could you identify the lines of code with a comment?
Something like: //**** Here the variable is null but should NOT be*****
"allow me to see what variable is the problem"
What variable IS THE PROBLEM?

[Wraithier]

The variable terminal. The user inputs this information and the program gets it with .getText. I successfully save the text in the CompName using .getText, I then have to pass this information from MapDrive.java to Drives.Java, it is successfully saved in MapDrive.java (I know this because of a println(), but when I try to use the same information again in Drives.Java the println() comes out as null...basically I get Y: \\null\\username\\password where null is supposed to be whatever is held in the variable terminal. Hopefully that helps, but again I'm not sure if I'm passing the variable incorrectly or what. Thanks for your help so far.

[Norm]

If you could put those comments in the code and post that, it would help. Otherwise its too much scrolling up and down.
How does the value of terminal get from MapDrive (where its saved) to Drives where it is null? I don't see where terminal is passed or referenced!
Where is the constructor for Drives?

[Wraithier]

Thanks for all your help Norm, I guess that is the problem. How do I go about passing the variable from the text field (CompName) in MapDrive to Drives? Both variables have the same name (Terminal) but I need to pass the value from MapDrive to Drives.

[Norm]

One way would be via Drives Constructor:

Code:

 ... = new Drives(terminal);
...

  public Drives(String t) {
      terminal = t:
 ...

[Wraithier]

would something like

Code:

MapDrive md = new MapDrive();
        
public String terminal = md.CompName.getText();

This would be in the Drives.java something like :

Code:

public class Drives implements Runnable
{
        MapDrive md = new MapDrive();
        
        public String terminal = md.CompName.getText();

	public boolean connected = false;  // tells if the conection to this terminal was possible or not
	        
	public boolean finished = false;  // tels if the thread has finished its work      
           
        Hashtable drives = new Hashtable();

work? I'm not exactly sure how to use the constructor to get the info from the text field. Use Drives constructor? I am trying to pass the info from MapDrives, which is assigned to the variable terminal. The value of terminal is determined by what the user inputs in the text field, this value then needs to be passed to Drives and used in the methods. So bascially the user inputs a computer name (terminal) and then the program maps the drives using net use commands. Sorry I am still fairly new at this and want to make sure I am understanding correctly.

[Norm]

How does the program run? Is this the way: It starts by creating the GUI in MapDrives, the user enters the terminal and then the Drives object is created. At this point you have the terminal value and need to pass it to the Drives object. You'd do that as I suggested above, by using the Drives constructor.

If you don't know how to use constructors and as basic as that is to Java programming, I'd suggest you find a java programming text and read up some before continuing. You are going to have LOTS of cases like this to solve and you need some basic understanding of how to create classes.

Good luck.
Norm

[Wraithier]

Thanks for your help again Norm. I was blowing the whole thing out of proportion. All I changed was this:

Code:

boolean success = mapDrive(drive, terminal, MapDrive.usernames[i],
			MapDrive.password);

to this

Code:

boolean success = mapDrive(drive, MapDrive.terminal, MapDrive.usernames[i],
			MapDrive.password);

I was forgetting to add in MapDrive. Now it's working.

[Norm]

A comment: Using public static isn't considered a good OOP technique. It's better to use methods/constructors to pass data from one class to another.

[Wraithier]

Thanks for the advice, I am pretty new at this so I appreciate any good programming tips.