openformatfile.java

一个简单的商品采集系统

//create the data-input-format file 
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class OpenFormatFile {
   
   private ObjectInputStream input;
   
   private int attributeNum;
   private ItemAttribute attributeArray[];
   private final int DEFAULT_NUM = 10; 
   private int keyIndex;
   public final int KEY = 1;
   
   public OpenFormatFile()
   {
      attributeNum = 0;
      attributeArray = new ItemAttribute[ DEFAULT_NUM ];
      openFile( );
      getFormatFile();

   }
   
   private void getFormatFile()
   {
   	  ItemAttribute r;
   	  try {
         while( true )
         {
         	r = ( ItemAttribute ) input.readObject();//need way to expand the array size
         	attributeArray[ attributeNum ] = r;     //while exception
         	if( attributeArray[ attributeNum].getConstrain() == KEY )
         	  keyIndex = attributeNum;
         	attributeNum++;  
         }
         
         
      }
      catch ( EOFException eofex ) {
         //JOptionPane.showMessageDialog( null,
            //"No more records in file",
            //"End of File", JOptionPane.ERROR_MESSAGE );
      }
      catch ( ClassNotFoundException cnfex ) {
         JOptionPane.showMessageDialog( null,
            "Unable to create object",
            "Class Not Found", JOptionPane.ERROR_MESSAGE );
      }
      catch ( IOException ioex ) {
         JOptionPane.showMessageDialog( null,
            "Error during read from file",
            "Read Error", JOptionPane.ERROR_MESSAGE );
      }
   }
   
   private void openFile( )
   {
      JFileChooser fileChooser = new JFileChooser();
      fileChooser.setFileSelectionMode(
         JFileChooser.FILES_ONLY );
      
      int result = fileChooser.showSaveDialog( null );
      // user clicked Cancel button on dialog
      if ( result == JFileChooser.CANCEL_OPTION )
         return;
         
      File fileName = fileChooser.getSelectedFile();
      
      if ( fileName == null ||
           fileName.getName().equals( "" ) )
         JOptionPane.showMessageDialog( null, 
            "Invalid File Name",            
            "Invalid File Name",
            JOptionPane.ERROR_MESSAGE );
      else {
         // Open the file
         try {
            
            	input = new ObjectInputStream(
                                 new FileInputStream( fileName ) );
         }
         catch ( IOException e ) {
            JOptionPane.showMessageDialog( null,
               "Error Opening File", "Error",
               JOptionPane.ERROR_MESSAGE );
         }      
       }
   }
   
   public ItemAttribute[] getAttribute()
   {
   	  return attributeArray;
   }
   
   public int getAttributeNum()
   {
   	  return attributeNum;
   }
   
   public int getKeyIndex()
   {
   	  return keyIndex;
   }
}