readfile.java

一个简单的商品采集系统

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

public class ReadFile extends JFrame {
   
   private ObjectInputStream input;
   private OperatePanel userInterface;
   private JButton nextRecord, open;
   
   private int attributeNum;
   private String attributeNames[];
   private ItemAttribute attributeArray[];
   
   // Constructor -- initialize the Frame 
   public ReadFile()
   {
      super( "Reading a Sequential File of Records" );

      getContentPane().setLayout( new BorderLayout() );
      
      JOptionPane.showMessageDialog( null, "First choose the Format-File"); 
      OpenFormatFile fget = new OpenFormatFile();
      
      attributeNum = fget.getAttributeNum();
     
      attributeArray = new ItemAttribute[ attributeNum ];
      attributeArray = fget.getAttribute();
      
      attributeNames = new String[  attributeNum ];
      for( int i = 0; i < attributeNum; i++ )
         attributeNames[ i ] = attributeArray[ i ].getName();
         
      
      userInterface = new OperatePanel( attributeNum, attributeNames );
      
      nextRecord = userInterface.getDoTask1();
      nextRecord.setText( "Show Record" );
      nextRecord.setEnabled( false );  
 
      nextRecord.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {               
               readRecord();
               nextRecord.setText( "Next Record" );
            }
         }
      );
 
      addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               if( input != null)
                 closeFile();
            }
         }
      ); 
      open = userInterface.getDoTask2();

      open.setText( "Open Data-File" );
      open.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
                 openFile();
            }
         }
      );
      
      getContentPane().add( userInterface, 
                            BorderLayout.CENTER );
      pack();
      setSize( 300, 200 );
      show();
   }

   private void openFile()
   {
      JFileChooser fileChooser = new JFileChooser();

      fileChooser.setFileSelectionMode(
         JFileChooser.FILES_ONLY );
      int result = fileChooser.showOpenDialog( this );
 
      // user clicked Cancel button on dialog
      if ( result == JFileChooser.CANCEL_OPTION )
         return;

      File fileName = fileChooser.getSelectedFile();
 
      if ( fileName == null ||
           fileName.getName().equals( "" ) )
         JOptionPane.showMessageDialog( this,
            "Invalid File Name",
            "Invalid File Name",
            JOptionPane.ERROR_MESSAGE );
      else {
         // Open the file
         try {
            input = new ObjectInputStream(
                        new FileInputStream( fileName ) );
            open.setEnabled( false );
            nextRecord.setEnabled( true );
         }
         catch ( IOException e ) {
            JOptionPane.showMessageDialog( this,
               "Error Opening File", "Error",
               JOptionPane.ERROR_MESSAGE );
         }      
      }
   }

   public void readRecord()
   {
      GoodsRecord record;

      // input the values from the file
      try {
         record = ( GoodsRecord ) input.readObject();
         GoodsField fieldArray[] = new GoodsField[ attributeNum ];
         fieldArray = record.getGoodsRecord();
         String values[] = new String[ attributeNum ];
         
         for( int i =0; i < attributeNum; i++)
         {
         	values[ i ] = fieldArray[ i ].getValue();
         }
         
         userInterface.setFieldValues( values );
      }
      catch ( EOFException eofex ) {
         nextRecord.setEnabled( false );
         JOptionPane.showMessageDialog( this,
            "No more records in file",
            "End of File", JOptionPane.ERROR_MESSAGE );
      }
      catch ( ClassNotFoundException cnfex ) {
         JOptionPane.showMessageDialog( this,
            "Unable to create object",
            "Class Not Found", JOptionPane.ERROR_MESSAGE );
      }
      catch ( IOException ioex ) {
         JOptionPane.showMessageDialog( this,
            "Error during read from file",
            "Read Error", JOptionPane.ERROR_MESSAGE );
      }
   }

   private void closeFile()
   {
      try {
         input.close();
         //System.exit( 0 );
      }
      catch ( IOException e ) {
         JOptionPane.showMessageDialog( this,
            "Error closing file",
            "Error", JOptionPane.ERROR_MESSAGE );
         System.exit( 1 );
      }
   }

   //public static void main( String args[] )
   //{
      //new ReadFile();
   //}
}