displayfile.java

Java 程序设计教程（第五版）EXAMPLESchap9源码

//********************************************************************
//  DisplayFile.java       Author: Lewis/Loftus
//
//  Demonstrates the use of a file chooser and a text area.
//********************************************************************

import java.util.Scanner;
import java.io.*;
import javax.swing.*;

public class DisplayFile
{
   //-----------------------------------------------------------------
   //  Opens a file chooser dialog, reads the selected file and
   //  loads it into a text area.
   //-----------------------------------------------------------------
   public static void main (String[] args) throws IOException
   {
      JFrame frame = new JFrame ("Display File");
      frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

      JTextArea ta = new JTextArea (20, 30);
      JFileChooser chooser = new JFileChooser();

      int status = chooser.showOpenDialog (null);

      if (status != JFileChooser.APPROVE_OPTION)
         ta.setText ("No File Chosen");
      else
      {
         File file = chooser.getSelectedFile();
         Scanner scan = new Scanner (file);

         String info = "";
         while (scan.hasNext())
            info += scan.nextLine() + "\n";

         ta.setText (info);
      }

      frame.getContentPane().add (ta);
      frame.pack();
      frame.setVisible(true);
   }
}