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Java expert help needed - Code attached

Posted on 2011-09-07
Last Modified: 2012-05-12
Hi experts,

Please find attached the file which can be run to view the output. When you view the output, you can notice two text fields and a browse button corresponding to each text field. I need to modify this in such a way that, I do not want to browse and find the input file, instead I just need to drag and drop a file to this textfield, such that, the file path comes there. Also, I should have the option to type the path of the file.
Any help in this regard which provides me the perfect solution would be much appreciated with points.

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class TextAcceleratorExample extends JFrame{
       JTextField textField = new JTextField(50);
       JTextField textField_2 = new JTextField(50);
       JButton button_Extract = new JButton("Extract");
       JButton button_Cancel = new JButton("Cancel");
       String text_1 ;
       String text_2;
     JButton button;
     JButton button_2;
     private JPanel getContent() {
            // Try changing columns argument.
             button = new JButton("Browse");
             button_2 = new JButton("Browse");
            JPanel panel = new JPanel(new GridBagLayout());
            GridBagConstraints gbc= new GridBagConstraints();
            gbc.insets = new Insets(5,15,5,0);
            gbc.weightx = 1.0;
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.anchor = GridBagConstraints.CENTER;
            panel.add(new JLabel("Enter Input Path  : "), gbc);
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1.0;
            gbc.gridx = 1;
            gbc.gridy = 0;
            gbc.anchor = GridBagConstraints.FIRST_LINE_END;
            gbc.insets = new Insets(10,0,5,5);
            //textField.setPreferredSize(new Dimension(100,20));
            panel.add(textField, gbc);
            gbc.fill = GridBagConstraints.NONE;
            gbc.anchor = GridBagConstraints.WEST;
            button.addActionListener(new OpenL());
            gbc.gridx = 2;
            gbc.gridy = 0;
            gbc.insets = new Insets(5,5,5,5);
            panel.add(button, gbc);
            GridBagConstraints gbc_2 = new GridBagConstraints();
            gbc.insets = new Insets(5,15,5,0);
            gbc_2.weightx = 1.0;
            gbc_2.gridy = 1;
            gbc_2.gridx = 0;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.anchor = GridBagConstraints.CENTER;
            panel.add(new JLabel("Enter Output Path : "), gbc_2);
            gbc_2.fill = GridBagConstraints.HORIZONTAL;
            gbc.insets = new Insets(10,0,5,5);
            gbc.weightx = 1.0;
            gbc_2.gridx = 1;
            gbc_2.gridy = 1;
            gbc.anchor = GridBagConstraints.WEST;
           // textField_2.setPreferredSize(new Dimension(100,20));
            panel.add(textField_2, gbc_2);
            gbc_2.fill = GridBagConstraints.NONE;
            gbc_2.anchor = GridBagConstraints.EAST;
            button_2.addActionListener(new OpenL());
            gbc_2.gridx = 2;
            gbc_2.gridy = 1;
            gbc_2.insets = new Insets(5,5,5,5);
            GridBagConstraints gbc_3 = new GridBagConstraints();
            gbc_3.insets = new Insets(3,3,10,30);
            gbc_3.weightx = 1.0;
            gbc_3.gridy = 4;
            gbc_3.gridx = 1;
            gbc_3.fill = GridBagConstraints.VERTICAL;
            gbc_3.anchor = GridBagConstraints.CENTER;
            button_Extract.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                   // showDialog("Extract");

                    String fileInput = textField.getText();
                    String fileOutput = textField_2.getText() + System.getProperty("file.separator") + "hci_final.log";
                       // DataInputStream in = new DataInputStream(new FileInputStream(fileInput));
                        PrintStream psout = new PrintStream(new FileOutputStream(fileOutput));
                        BufferedReader r = new BufferedReader(new FileReader(fileInput));
                        String buff = null;
                        boolean reading = false;
                        int count = 0;

                        while((buff=r.readLine()) != null){
                                       if(buff.trim().length() == 0)continue;
                            System.out.println (count + "  I: " + buff.indexOf(" I "));
                             System.out.println (count + "  D: " + buff.indexOf(" D "));

                           // System.out.println(count + ": " + buff);

                            if((buff.indexOf("SENT")> -1) ||buff.indexOf("RCVD") > -1 && (reading == false)){
                                reading = true;
                                if(buff.charAt(31)== 'I')psout.println(buff);
                            if(buff.indexOf("--") > -1 && reading == true){
                                reading = false;
                                  if(buff.charAt(31)== 'I')psout.println(buff);


                                 if(buff.charAt(31)== 'I')psout.println(buff);

showDialog("File extraction is success " );

                    } catch(Exception ex){
             }) ;
            return panel;
     class OpenL implements ActionListener {
            public void actionPerformed(ActionEvent e) {
                int rVal = -1;
                if(e.getSource().equals(button)) {
              JFileChooser c = new JFileChooser();
              // Demonstrate "Open" dialog:
              rVal = c.showOpenDialog(TextAcceleratorExample.this);
              if (rVal == JFileChooser.APPROVE_OPTION) {
              //    textField_2.setText(c.getCurrentDirectory().toString());
                  text_1 = textField.getText();
                  text_2 = textField_2.getText();
                  System.out.print("textField" + textField.getText());

                        JFileChooser c1 = new JFileChooser();
                     rVal = c1.showOpenDialog(TextAcceleratorExample.this);
                     if (rVal == JFileChooser.APPROVE_OPTION) {

              if (rVal == JFileChooser.CANCEL_OPTION) {
                  textField.setText("You pressed cancel");

        public static void main(String[] args) {
            JFrame f = new JFrame();
           // f.add();
            f.add(new TextAcceleratorExample().getContent());
            f.setTitle("SIGNAL EXTRACTOR");
        private void showDialog(String s){
            JOptionPane.showMessageDialog(this, s, "Button says: ", JOptionPane.PLAIN_MESSAGE);


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Question by:Sreejith22
  • 7
  • 3
LVL 47

Expert Comment

ID: 36500672

There is no problem with typing file path in the textfiled - what kind of doubts you have on this subject - just type, and
then use getText() method and use the string whicvh you get as a file name

As to drag the file - do you mean you want to drag the file from outside your java application - say from Windows
folder window? That seems problematic to me.

Expert Comment

ID: 36500698
well drag and drop for swing elements is posible, but not really "easy"  there is a complete tutorial here, check it out,

LVL 47

Expert Comment

ID: 36500711
Drag and Drop is possible fomr one java component to another - but from system window to java application - well, everything is possible
but it is problematic. You can probably do something through clipboard, but direct drag into Java window from say your desktop
seesm difficult
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Author Comment

ID: 36500719
>>As to drag the file - do you mean you want to drag the file from outside your java application - say from Windows folder window?

Yes, I want to drag file and drop it inside textfield, so that, the path comes there automatically.
LVL 47

Expert Comment

ID: 36500722
But you want to take the file say, from your desktop, or from say JFileChooser window?

Waht is your OS ?
LVL 47

Expert Comment

ID: 36500729
LVL 47

Expert Comment

ID: 36500741

Author Comment

ID: 36500781
>>But you want to take the file say, from your desktop, or from say JFileChooser window?

Destop or from any other Windows folder
LVL 47

Accepted Solution

for_yan earned 250 total points
ID: 36500846

Actually indeed it works - try to compile
it and drag some file to the upper textfield -
it shows the path there.

Then start form this code and add your buttons and functionality -
that qwould be really straigthforward

package dnd;

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;

public class DnDFrame extends javax.swing.JFrame implements DropTargetListener {

    private DefaultListModel listModel = new DefaultListModel();
    private DropTarget dropTarget1;
       private DropTarget dropTarget2;

    /** Creates new form DnDFrame */
    public DnDFrame() {
           dropTarget1 = new DropTarget(jtxt1, this);
        //  dropTarget2 = new DropTarget(jtxt2, this);

       // dropTarget = new DropTarget(list, this);
     //   list.setModel(listModel);
      //  list.setDragEnabled(true);
      //  list.setTransferHandler(new FileTransferHandler());
        jtxt1.setTransferHandler(new FileTransferHandler());
          //jtxt2.setTransferHandler(new FileTransferHandler());


    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {
        java.awt.GridBagConstraints gridBagConstraints;

        jLabel1 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        list = new javax.swing.JList();
        jtxt1 = new JTextField(20);
        jtxt2 = new JTextField(20);

         getContentPane().setLayout(new java.awt.GridLayout(2,1));

        getContentPane().setLayout(new java.awt.GridBagLayout());

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridwidth = java.awt.GridBagConstraints.REMAINDER;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.WEST;
        getContentPane().add(jLabel1, gridBagConstraints);


        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridwidth = java.awt.GridBagConstraints.REMAINDER;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        getContentPane().add(jScrollPane1, gridBagConstraints);

    }// </editor-fold>
    // Variables declaration - do not modify
    private javax.swing.JLabel jLabel1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JList list;
      private javax.swing.JTextField jtxt1;
     private javax.swing.JTextField jtxt2;

    // End of variables declaration

    public void dragEnter(DropTargetDragEvent arg0) {
        // nothing

    public void dragOver(DropTargetDragEvent arg0) {
        // nothing

    public void dropActionChanged(DropTargetDragEvent arg0) {
        // nothing

    public void dragExit(DropTargetEvent arg0) {
        // nothing

    public void drop(DropTargetDropEvent evt) {
        int action = evt.getDropAction();
        try {
            Transferable data = evt.getTransferable();
            if (data.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
                List<File> files = (List<File>) data.getTransferData(
                for (File file : files) {
                  //  listModel.addElement(file);
        } catch (UnsupportedFlavorException e) {
        } catch (IOException e) {
        } finally {


    private class FileTransferHandler extends TransferHandler {

        protected Transferable createTransferable(JComponent c) {
            JList list = (JList) c;
            List<File> files = new ArrayList<File>();
            for (Object obj: list.getSelectedValues()) {
            return new FileTransferable(files);

        public int getSourceActions(JComponent c) {
            return MOVE;

    private class FileTransferable implements Transferable {

        private List<File> files;

        public FileTransferable(List<File> files) {
            this.files = files;

        public DataFlavor[] getTransferDataFlavors() {
            return new DataFlavor[]{DataFlavor.javaFileListFlavor};

        public boolean isDataFlavorSupported(DataFlavor flavor) {
            return flavor.equals(DataFlavor.javaFileListFlavor);

        public Object getTransferData(DataFlavor flavor)
                throws UnsupportedFlavorException, IOException {
            if (!isDataFlavorSupported(flavor)) {
                throw new UnsupportedFlavorException(flavor);
            return files;

    public static void main(String[] args) {
        new DnDFrame();

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Author Comment

ID: 36500848
pls, any code snippet which would prove to be an apt solution is much appreciated.
LVL 47

Expert Comment

ID: 36500876
see code above

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