Update jar file with modified class files

Question

hi all,
I'm developing a jar utility for updating a jar file with modified class files as of now i have reached a point where in i can browse files and set it to required location
i.e i have developed a swings GUI application using JfileChooser and browse the files ..now my requirement is to update the jar files with modified class file
GUI looks like below
....enter the modified class file ----> d:\c.class
....enter the jar file path ---> d:\a.jar
                                                      update button now i have the requirement as
1> when i click on the update button ,my jar file (a.jar) should get updated with the latest class file (c.class)
can u help me to achieve this requirement.???
im stuck with this,,,if u can provide me wit the code for updating jar file with latest class file...it will really be helpful
if u can help me with the code on click on update button it will be really helpful
Thanks and expecting a faster response from u all java experts....

Answer 1

Please find my query in bolds...i have written the partial code now,i need some help now
hope u guys can help me out...
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
public class FileExplorer extends JDialog implements ActionListener
     JTextField txtLocation_class;
     JButton btnBrowse_class;
     JLabel label_class;
     JTextField txtLocation_jar;
     JButton btnBrowse_jar;
     JLabel label_jar;
     JButton updatebutton;
     public FileExplorer()
               setSize(600,300);
               //for class files
               label_class = new JLabel("Please select Modified Class File");
               txtLocation_class= new JTextField(20);
               btnBrowse_class = new JButton("Browse");
               btnBrowse_class.addActionListener(this);
               //for jar files               
               label_jar = new JLabel(" Please select the Jar file");
               txtLocation_jar= new JTextField(20);
               btnBrowse_jar = new JButton("Browse");
               btnBrowse_jar.addActionListener(this);
               ActionListener updateListener = new ActionListener(){
                public void actionPerformed(ActionEvent ae){
                 if(ae.getActionCommand().equalsIgnoreCase("Update")){               
                  System.out.println("ae.getActionCommand() :: "+ae.getActionCommand());
                  System.out.println("Update Button is pressed");               
                *//Query :how do i access FilePath and FilePath1 here which*
*                // has been set in public void actionPerformed(ActionEvent ae)*
*                //method below*
*                // FilePath  ---??*
*                // FilePath1  ---??*
*                // how do i access the above 2 parameters*
*                //Query :on click of update button i have to pass*
*                //two parameters FilePath and FilePath1 to*
*                //perform some functionality. please help me*
*                //to achieve this..how do i access Filepath and Filepath1*
*                //here which has been set below.*
                 } // end of if               
               } // end of actionPerformed
            };// end of ActionListener
              updatebutton = new JButton("Update");
              updatebutton.addActionListener(updateListener);
               //adding to the panel               
               JPanel pnl = new JPanel();
               pnl.add(label_class);
               pnl.add(txtLocation_class);
               pnl.add(btnBrowse_class);
               pnl.add(label_jar);
               pnl.add(txtLocation_jar);
               pnl.add(btnBrowse_jar);
              pnl.add(updatebutton);
               getContentPane().add(pnl);                         
     public void actionPerformed(ActionEvent ae)
          Object obj=ae.getSource();
          if(obj==btnBrowse_class)
               final JFileChooser fcstudent = new JFileChooser();
               int rtrnval = fcstudent.showOpenDialog(this);
               if(rtrnval==JFileChooser.APPROVE_OPTION)
                    try
                         File file=fcstudent.getSelectedFile();                         
                         String path = file.getPath();
                         System.out.println("This is Path:"+path);
                         txtLocation_class.setText(""+path);
                         String FilePath=txtLocation_class.getText();
                         System.out.println("FilePath is ::"+FilePath);                                        
                    catch(Exception ex)               
                         ex.printStackTrace();
          }else if(obj==btnBrowse_jar){
                         final JFileChooser fcstudent = new JFileChooser();
                         int rtrnval = fcstudent.showOpenDialog(this);
                         if(rtrnval==JFileChooser.APPROVE_OPTION)
                              try
                                   File file=fcstudent.getSelectedFile();                         
                                   String path1 = file.getPath();
                                   System.out.println("This is Path:"+path1);
                                   txtLocation_jar.setText(""+path1);
                                   String FilePath1=txtLocation_jar.getText();
                                   System.out.println("FilePath is ::"+FilePath1);                                        
                              catch(Exception ex)               
                                   ex.printStackTrace();
     public static void main(String arg[]){
               FileExplorer Exm= new FileExplorer();
               Exm.setVisible(true);
}