How do I create a Data folder in my C: Drive using my Java program

[Xavier Downing]

My assignment requires that I use exception handling to create a directory and file if necessary.

I was able to create a C:Data\inventory.dat file, provided that there's an existing Data folder (directory) in my C: drive; however, I have a feeling that the assignment wants me to create an actual Data folder if one is not available. When I remove the Data folder from my C: drive, I get "C:\data\inventory.dat (The system cannot find the path specified)".

How am I to create able a folder that currently does not exist? I'm reading the java.sun website on the File class, the mkdirs methods, and the FileSystemView class; however, I'm having trouble implementing the requirements in my code (I wish API documentation was more understandable to me.). Can an example be provided? Thank you everyone.

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.HeadlessException;
import java.awt.Image;
 
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
 
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
 
 
public class InventoryGUI extends JFrame implements ActionListener,Serializable 
{
   private JTextArea textArea;
   
   private JButton first,
   next,
   previous,
   last,
   add,
   modify,
   delete,
   save,
   search,
   exit;
   
   JLabel imageLabel;
   
   private static Inventory inv = new Inventory();
 
   /**
 * @param arg0
 * @throws HeadlessException
 */
   public InventoryGUI( String arg0 ) throws HeadlessException 
   {
  super( "Inventory GUI" );
  
  textArea = new JTextArea( 250,30 );
 
  JScrollPane scrollPane = new JScrollPane( textArea ); 
 
  textArea.setEditable( false );
 
  scrollPane.setVerticalScrollBarPolicy( JScrollPane.VERTICAL_SCROLLBAR_ALWAYS );
 
  scrollPane.setPreferredSize( new Dimension( 250, 250 ) );
 
  JPanel cp = new JPanel();
 
  cp.setSize( 250, 40 );
 
  cp.setLayout( new BorderLayout() );
 
  cp.add( scrollPane,BorderLayout.CENTER );
  
  JPanel buttonPaenl = new JPanel();
  
  JPanel buttonPaenl1 = new JPanel();
 
  first = new JButton( "First" );
  first.addActionListener( this );
  
  search = new JButton( "Search" );
  search.addActionListener( this );
  
  next = new JButton( "Next" );
  next.addActionListener( this );
 
  previous = new JButton( "Previous" );
  previous.addActionListener( this );
 
  last = new JButton( "Last" );
  last.addActionListener( this );
 
  add = new JButton( "Add" );
  add.addActionListener( this );
 
  modify = new JButton( "Modify" );
  modify.addActionListener( this );

  delete = new JButton( "Delete" );
  delete.addActionListener( this );
 
  save = new JButton( "Save" );
  save.addActionListener( this );
 
  exit = new JButton( "Exit" );
  exit.addActionListener( this );

  buttonPaenl.setLayout( new FlowLayout() );
  buttonPaenl1.setLayout( new FlowLayout() );
  buttonPaenl.add( first );
  buttonPaenl.add( previous );
  buttonPaenl.add( next );
  buttonPaenl.add( last );
  buttonPaenl1.add( add );
  buttonPaenl1.add( modify );
  buttonPaenl1.add( delete );
  buttonPaenl1.add( save );
  buttonPaenl1.add( search );
  buttonPaenl1.add( exit );
 
  cp.add( buttonPaenl,BorderLayout.SOUTH );
  cp.add( buttonPaenl1,BorderLayout.NORTH );
 
  ImageIcon icon = new ImageIcon( "logo.gif" );
  imageLabel = new JLabel( icon, JLabel.CENTER );
  cp.add( imageLabel, BorderLayout.EAST );
  this.setContentPane( cp );
 
  this.setTitle( " Week Nine Final Project: Inventory Program Part Six - Transformers Autobot Inventory ( More Than Meets the Eye o_0?! ) " );
 
  this.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
  this.textArea.setText(inv.getFirst());
  this.setSize(400, 400);
  this.pack();
  this.setVisible( true );
   }
 
   @Override
   public void actionPerformed( ActionEvent e ) 
   {
  // TODO Auto-generated method stub
  if( e.getActionCommand().equals( "First" ) )
  {
 textArea.setText( inv.getFirst() );
  }
  
  if( e.getActionCommand().equals( "Next" ) )
  {
 textArea.setText(inv.getNext());
  }

  if( e.getActionCommand().equals( "Previous" ) )
  {
 textArea.setText( inv.getPrevious() );
  }
  
  if( e.getActionCommand().equals( "Last" ) )
  {
 textArea.setText(inv.getLast());
  }
  
  if( e.getActionCommand().equals( "Save" ) )
  {
 save();
  }

  if( e.getActionCommand().equals( "Exit" ) )
  {
 System.exit(0);
  }

  if( e.getActionCommand().equals( "Add" ) ) 
  {
 InventoryDialogue id = new InventoryDialogue( true," Add a new Inventory " );
  }
  
  if( e.getActionCommand().equals( "Modify" ) )
  {
 InventoryDialogue id = new InventoryDialogue( false," Modify Inventory " );
  }
  
  if( e.getActionCommand().equals( "Search" ) )
  {
 String s = JOptionPane.showInputDialog( null, " Enter Product Name ",null, 1 );
 
 s = inv.Search(s);
 
 if( s == null )
 {
JOptionPane.showMessageDialog( this, " No Results Found " );
 } 

 else textArea.setText( s );
  }

  if( e.getActionCommand().equals( "Delete" ) )
  {
 inv.getproducts().remove( inv.index );
  }
  
   }
   
   public void save()
   {
  File f = new File( "C:\\data\\inventory.dat" );
  
  try 
  {  
 FileOutputStream out = new FileOutputStream( f );
 
 try 
 {
ObjectOutputStream objectOut = new ObjectOutputStream( out );
   objectOut.writeObject( inv );
 } 
 
 catch (IOException e) 
 {
// TODO Auto-generated catch block
JOptionPane.showMessageDialog( null, e.getMessage() );
   e.printStackTrace();
 }
  } 
  
  catch ( FileNotFoundException e ) 
  {
 // TODO Auto-generated catch block
 JOptionPane.showMessageDialog( null, e.getMessage() );
e.printStackTrace();
  }
 
   }  
 
   public static Inventory getInv() 
   {
  return inv;
   }
 
   public static void setInv( Inventory inv ) 
   {
  InventoryGUI.inv = inv;
   }
 
   /**
* @param args
*/
   public static void main( String[] args ) 
   {
  InventoryGUI inventory = new InventoryGUI( "Inventory" );
   }
}

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
 
 
public class InventoryDialogue extends JFrame implements ActionListener
{
   private boolean status = false; //false is for modify
   
   JTextField nameTextField,
  unitTextField,
  priceTextField;
   
   JLabel nameLabel,
  unitLabel,
  priceLabel;

   JPanel TextFields,
  buttons;
   
   JButton modify, 
   add;

   public InventoryDialogue( Boolean stat, String title )
   {
  super( title );
  status = stat;
  JPanel but = new JPanel();
  modify = new JButton( "Modify" );
  modify.addActionListener( this );
  add = new JButton( "Add" );
  add.addActionListener( this );
  but.add( add );
  but.add( modify );
  
  if( status == false )
  {
 add.setVisible( false );
  }
  
  else
  {
 modify.setVisible( false );
  }
  
  nameTextField = new JTextField( "", 20 );
  unitTextField = new JTextField( "", 5 );
  priceTextField = new JTextField( "" , 5 );
  nameLabel = new JLabel( "Name" );
  unitLabel = new JLabel( "Units" );
  priceLabel = new JLabel( "Price per Unit" );
  JPanel p = new JPanel();
 
  p.setLayout( new FlowLayout() );
  p.add( nameLabel );
  p.add( nameTextField );
  p.add( unitLabel );
  p.add( unitTextField );
  p.add( priceLabel );
  p.add( priceTextField );
  JPanel cp = new JPanel();
  cp.setLayout( new BorderLayout() );
  cp.add( p, BorderLayout.CENTER );
  cp.add( but, BorderLayout.EAST );
  this.setContentPane( cp );
  this.setDefaultCloseOperation( JFrame.DISPOSE_ON_CLOSE );
  this.pack();
  this.setVisible( true );
   }
 
   @Override
   public void actionPerformed( ActionEvent arg0 ) 
   {
  if( arg0.getActionCommand().equals( "Add" ) )
  {
 String name;
 int units;
 Double price;
 name = nameTextField.getText();
  
 try 
 {
units = Integer.parseInt( unitTextField.getText() );
 } 
  
 catch ( NumberFormatException e ) 
 {
JOptionPane.showMessageDialog( null, e.getMessage() );
 
e.printStackTrace();
 
return;
 }
  
 try 
 {
price = Double.parseDouble( priceTextField.getText() );
 } 
  
 catch ( NumberFormatException e ) 
 {
// TODO Auto-generated catch block
JOptionPane.showMessageDialog( null, e.getMessage() );
 
e.printStackTrace();
 
return;
 }

 InventoryGUI.getInv().getproducts().add( new ProductModified( name, InventoryGUI.getInv().products.size(), 
   units,price ) );
  
 this.dispose();
  }
 
  if( arg0.getActionCommand().equals( "Modify" ) )
  {
 String name;
 int units;
 Double price;
 name = nameTextField.getText();
  
 try 
 {
units = Integer.parseInt( unitTextField.getText() );
 } 
  
 catch ( NumberFormatException e ) 
 {
JOptionPane.showMessageDialog( null,"Please Enter Valid Integers" );
 
e.printStackTrace();
 
return;
 }

 try 
 {
price = Double.parseDouble( priceTextField.getText() );
 } 
  
 catch ( NumberFormatException e ) 
 {
// TODO Auto-generated catch block
JOptionPane.showMessageDialog( null,"Please Enter Valid Price" );
 
//e.printStackTrace();
return;
 }

 InventoryGUI.getInv().getproducts().set( InventoryGUI.getInv().index, 
new ProductModified( name, InventoryGUI.getInv().index, units, price ) );

 this.dispose();
  }
 
   }
   
   public static void main( String args[] )
   {
  InventoryDialogue idf = new InventoryDialogue( true,"cc" );
   }
}

import java.text.Collator;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Locale;
import java.io.Serializable;
 
public class Inventory implements Serializable
{
   private String inventoryName; // name of inventory
   
   public String restockRate; // restock rate percentage
   
   public double totalRestock;
 
   public static int index;
 
   public ArrayList < ProductModified > products = new ArrayList < ProductModified > ();
 
   public Inventory()
   {
  products.add( new ProductModified( "No Sale Bot", 0, 1, 0.00 ) );
  products.add( new ProductModified( "Optimus Prime", 7, 52, 160.00 ) );
  products.add( new ProductModified( "BumbleeBee", 16, 61, 97.00 ) );
  products.add( new ProductModified( "Ironhide", 25, 106, 88.00 ) );
  products.add( new ProductModified( "Ratchet", 34, 125, 79.00 ) );
  products.add( new ProductModified( "Jazz", 0, 124, 70.00 ) );
  
  index = 0;
   }

   public void sort()
   {
  Locale loc = Locale.ENGLISH;
   
  ProductModified Temp;
   
  Collator col = Collator.getInstance( loc );
   
  for ( int i = 0; i < products.size(); i++ ) 
  {
 for ( int j = i + 1; j < products.size(); j++ )
 {
if( col.compare( products.get( i ).getAutobotName(), products.get( j ).getAutobotName() ) > 0 )
{
   Temp = products.get( i );

   products.set( i, products.get( j ) );
   products.set( j, Temp );
}
 }
  }
   }

   public String getInventoryName() 
   {
  return inventoryName;
   }

public void setInventoryName( String inventoryName ) 
{
   this.inventoryName = inventoryName;
}

public String getRestockRate() 
{
   return restockRate;
}

public void setRestockRate( String restockRate ) 
{
   this.restockRate = restockRate;
}

public double getTotalRestock() 
{
   return totalRestock;
}

public void setTotalRestock( double totalRestock ) 
{
   this.totalRestock = totalRestock;
}

public ArrayList < ProductModified > getproducts() 
{
   return products;
}

public void seproducts( ArrayList < ProductModified > products) 
{
   this.products = products;
}

public String toString()
{
   String transformersSub = new String(" ");
 
   transformersSub = "Welcome to the\n" + getInventoryName() + "!\n\n";
 
   transformersSub = transformersSub + "Below is the available inventory:\n\n";
 
   transformersSub = transformersSub + "The restock interest rate is at " + getRestockRate() + ".\n\n";
 
   transformersSub = transformersSub + "Index\tProductModified #\t\t\tName\t\tUnits\t\tPrice\t\t";
 
   transformersSub = transformersSub + "Unit Restock Value\t";
 
   transformersSub = transformersSub + "Stock Value\t\t";
 
   transformersSub = transformersSub + "Total ProductModified Restock\n";
   
   Iterator < ProductModified > i = this.getproducts().iterator();
   
   while(i.hasNext())
   {
  transformersSub = transformersSub + i.next();
   }
   
  return transformersSub;
   }
   
   public Double getTotal()
   {
  Double Total = 0.0;
  
  ProductModified p;
  
  Iterator < ProductModified > i = products.iterator();
  
  while( i.hasNext() )
  {
p = i.next();

Total = Total + p.getPrice() * p.getUnit();
  }
  
  return Total;
   }
 
   public String processOutPut( ProductModified p )
   {
  String out = "Welcome to the Transformers Autobot Toy Inventory\n\nTotal Inventory = " 
  + this.getTotal() + "\nRestocking Fee = 5%" 
  + "\n\nItem #\tName\tUnit\tPrice\tUnit Restock Value" 
  + p;
  
  return out;
   }
   
   public String getFirst()
   {
  index = 0;
  
  return processOutPut( products.get(0) );

   }
   
   public String getLast()
   {
  index = products.size() - 1;
  
  return processOutPut( products.get( products.size() - 1 ) );
   }

   public String getNext()
   {
  if( index == products.size() - 1 ) 
  {
 getFirst();
  
 return getFirst();
  } 
  
  else
  {
 index++;
 
 return processOutPut( products.get( index ) );
  }
   }
   
   public String getPrevious()
   {
  if( index == 0 )
  {
 return getLast();
  } 
  
  else

  return processOutPut(products.get(--index));
   }
   
   public String Search( String Search )
   {
  Iterator < ProductModified > i = products.iterator();
   
  String te = null;
   
  ProductModified p;
  
  while( i.hasNext() )
  {
 p = i.next();
  
 if( p.getAutobotName().equals( Search ) )
 {
te = processOutPut( p );
 }
  }
  
  return te;
   }
}
 

import static java.lang.System.out;
import java.io.Serializable;
 
//class declaration for TransformersProduct
public class Product implements Serializable
{
   public String autobotName; // array of autobot toy names
   public int productNumber; // product # array ID for product
   public int unit; // array of autobot toy units
   public double price; // array of autobot prices
   public double inventoryValue;

   /**
* @param autobotName
* @param productNumber
* @param unit   
* @param price
*/
   
   public Product( String autobotName, int productNumber, int unit,
   double price ) 
   {
  super();
  this.autobotName = autobotName;
  this.productNumber = productNumber;
  this.unit = unit;
  this.price = price;
   }
 
   public String getAutobotName() 
   {
  return autobotName;
   }
   
   public void setAutobotName( String autobotName ) 
   {
  this.autobotName = autobotName;
   }
 
   public int getProductNumber() 
   {
  return productNumber;
   }

   public void setProductNumber( int productNumber ) 
   {
  this.productNumber = productNumber;
   }
   
   public int getUnit() 
   {
  return unit;
   }
   
   public void setUnit( int unit ) 
   {
  this.unit = unit;
   }
   
   public double getPrice() 
   {
  return price;
   }
   
   public void setPrice( double price ) 
   {
  this.price = price;
   }

   public double getInventoryValue() 
   {
  return inventoryValue;
   }

   public Double inventoryValue()
   {
  return this.getPrice() * this.getUnit();
   }
   
   public String toString()
   {
  return "\n"+this.productNumber+"\t"+this.autobotName+"\t"+this.unit +"\t"+this.price+ "\t"; 
   }
}

import java.io.Serializable;
 
public class ProductModified extends Product implements Serializable
{
   public ProductModified( String autobotName, int productNumber, int unit,
   double price ) 
   {
  super( autobotName, productNumber, unit, price );
  this.inventoryValue = this.inventoryValue();
  // TODO Auto-generated constructor stub
   }

   public Double inventoryValue()
   {
  return this.getUnit() * this.getPrice() + this.getUnit() * this.getPrice() * 0.05;
   }
   
   public String toString()
   {
  return "\n" + this.productNumber + "\t" + this.autobotName 
  + "\t" + this.unit + "\t" + this.price + "\t" 
  + this.getInventoryValue(); 
   }
}

[ November 18, 2007: Message edited by: Xavier Downing ]

[Henry Wong]

How am I to create able a folder that currently does not exist? I'm reading the java.sun website on the File class, the mkdirs methods, and the FileSystemView class; however, I'm having trouble implementing the requirements in my code (I wish API documentation was more understandable to me.). Can an example be provided? Thank you everyone.

What is the "trouble" that you had with the mkdirs() method? it seems pretty straightforward to me.

Anyway, here is an example with the mkdirs() method. I put in some sanity checks too, to give you an example of other methods of the File class.

File jr = new File("c:\\javaranch");
 
if (jr.exists()) {
    if (!jr.isDirectory()) {
        System.out.println("JR already exist and not a directory");
    } else if (!jr.canWrite()) {
        System.out.println("JR already exist and not writeable");
    }
} else {
    jr.mkdirs();
}

Henry

[Xavier Downing]

Thanks! It's just that I'm such a dummy with creating codes from reading the API. When you read the API about the mkdirs, it doesn't tell you about using if and else statements to accomplish the task required. Usually, I read my textbook, or other reading materials (e.g. Java for Dummies) to help me out; however, none of the material touches on creating directories. When I take a look at the API, I'm like in the middle of an Ocean and can't swim. I wish I was able to read the API and formulate my code just off of that. I read the API and I'm like... so? What advice can you give me with regard to understanding the API well enough to create a code? Any code?
[ November 18, 2007: Message edited by: Xavier Downing ]