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Reading Directories and Files in Java

I have a combo box control in Java with a first element of "NEW". When i pull down the combo box menu it should display the files listed in a directory under windows. I should be able to open the file that I select and display the contents to a List Box. If I select "NEW" it should clear the contents of the List Box.

I need some code samples that I can try, which is the reason for the high points. If you've done this before or know where to get some code samples please provide information and I will award the points.

thanks
GS

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sudhakar_koundinya

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sudhakar_koundinya

the following code may helps you to write your further code

import javax.swing.*;
import java.io.*;
/*
* Created on Aug 10, 2004
*
* TODO To change the template for this generated file go to
* Window - Preferences - Java - Code Style - Code Templates
*/

/**
* @author Sudhakar
*
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
*/
public class AddFiles extends JFrame {

      JComboBox combo=new JComboBox();
      public AddFiles()
      {
            init();
      }
      public void init()
      {
            addFiles(combo,"c:/");
            JPanel pane=new JPanel();
            pane.add(combo);
            this.getContentPane().add(pane);
      }
      public static void main(String s[])
      {
            AddFiles files=new AddFiles();
            files.setSize( 400,300);
            files.show() ;
      }
      public void addFiles(JComboBox _combo,String file)
      {
            File dir = new File(file);

       String[] children = dir.list();
       if (children == null) {
       // Either dir does not exist or is not a directory
       } else {
       for (int i=0; i<children.length; i++) {
       // Get filename of file or directory
       String filename = children[i];
       _combo.addItem(filename );
       }
       }

      }

}

sudhakar_koundinya

and this is ur combo listener class
class MyActionListener implements ActionListener {
public void actionPerformed(ActionEvent ae)
      {
       if(ae.getSource() ==combo)
             {
                   JComboBox cb = (JComboBox)ae.getSource();
                   Object newItem = cb.getSelectedItem();
                   try
                  {
                         FileInputStream fin=new FileInputStream(newItem.toString());
                         File file=new File(newItem.toString());
                         int length=(int)file.length();
                         byte bytes[]=new byte[length];
                         fin.read(bytes);
                         String string=new String(bytes);
                         String[] lines=string.split( "\n");
                         for(int i=0;i<lines.length;i++)
                         {
                               list.add(lines[i],null);
                               System.err.println(lines[i]);
                         }

                  }
                   catch(Exception ex)
                  {

              }
             }
       }

jmeree

Why not use a JFileChooser like this? (created with netbeans)

import java.io.BufferedReader;
import javax.swing.JFileChooser;

public class FileViewer extends javax.swing.JFrame {

private javax.swing.JButton exitButton;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel3;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea jTextArea1;
private javax.swing.JButton newButton;
private javax.swing.JButton openButton;

public FileViewer() {
super("File Viewer");
initComponents();
}

private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jScrollPane1 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
jPanel2 = new javax.swing.JPanel();
jPanel3 = new javax.swing.JPanel();
openButton = new javax.swing.JButton();
newButton = new javax.swing.JButton();
exitButton = new javax.swing.JButton();

addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
}
});

jTextArea1.setPreferredSize(new java.awt.Dimension(300, 300));
jScrollPane1.setViewportView(jTextArea1);

jPanel1.add(jScrollPane1);

getContentPane().add(jPanel1, java.awt.BorderLayout.CENTER);

getContentPane().add(jPanel2, java.awt.BorderLayout.NORTH);

openButton.setLabel("Open");
openButton.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
openButtonMouseClicked(evt);
}
});

jPanel3.add(openButton);

newButton.setLabel("New");
newButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
newButtonActionPerformed(evt);
}
});
jPanel3.add(newButton);

exitButton.setLabel("Exit");
exitButton.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
exitButtonMouseClicked(evt);
}
});

jPanel3.add(exitButton);

getContentPane().add(jPanel3, java.awt.BorderLayout.SOUTH);

pack();
}

private void exitButtonMouseClicked(java.awt.event.MouseEvent evt) {
System.exit (0) ;
}

private void openButtonMouseClicked(java.awt.event.MouseEvent evt) {
JFileChooser chooser = new JFileChooser();
int returnVal = chooser.showOpenDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
java.io.File f = chooser.getSelectedFile();
System.out.println("You chose to open this file: " + f.getAbsolutePath() );
try {
BufferedReader br = new BufferedReader ( new java.io.FileReader(f) );
String tempLine = null ;
jTextArea1.setText(null);
while( ( tempLine = br.readLine() ) != null ) { jTextArea1.append( tempLine + "\n" ); }
}
catch ( java.io.FileNotFoundException e ) {
e.printStackTrace();
System.exit (-1);
}
catch ( java.io.IOException e ) {
e.printStackTrace();
System.exit (-1);
}
}
}

private void newButtonActionPerformed(java.awt.event.ActionEvent evt) {
jTextArea1.setText(null);
}

/** Exit the Application */
private void exitForm(java.awt.event.WindowEvent evt) {
System.exit(0);
}

public static void main(String args[]) {
new FileViewer().show();
}

}

GoldStrike

ASKER

thanks for all the inputs, I apologize for being late. The GetFiles and Add Items answered my questions.

sudhakar_koundinya

:-)