Swing JFileChooser

[sc_3007]

Hi,

I have a dilemma. It should be possible but I can't seem to add a file chooser into a JPanel. What I am trying to is put a file chooser in my main window of my swing applet. I know it is possible but I can't seem to find the right way to do it.

Any Ideas???

Many Thanks,

Steve

[evlich]

Can you post the code that you are using?

[graviton]

applet?
applets may not access files and thus perhaps not access jfilechooser.
have a look at other threads in this forum.
for applications you can have a look at http://java.sun.com/docs/books/tutor...lechooser.html.
by the way: jfilechooser will open it's own jframe and is not thought as en embedded control.

[sc_3007]

Yes, I am using an applet. I'll explain, what I am trying to do is write an SFTP client for my website but in applet form. I am going to use the JFileChooser as the basis for my drag and drop transfer GUI. I know applets can access files because I have seen FTP client applets so I know it can be done. Please Please Please though if you know a better way to do it then please fill me in. I am very open to changing my methods or techniques if it makes for better software. I have read the tutorial you suggested, infact it has been like my bible thus far!!! lol. Here is my code sofar, Its very rough at the moment, I will clean it all up once I have a working solution.

CODE:

/*
	***********************************
	Sting SFtp
	Creator: Stephen Cheesley
	Designer: Stephen Cheesley
	***********************************
*/

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

public class Sting extends JApplet implements ActionListener
{

	//Methods to load on applet initialisation
	public void init()
	{
		try
		{
			javax.swing.SwingUtilities.invokeAndWait(new Runnable()
			{
				public void run()
				{
			    	guiLayout();
			    }
			});

		}
		catch (Exception e)
		{
			System.err.println("guiLayout didn't successfully complete");
		}


	}

	public void start()
	{

	}

	public void stop()
	{

	}


	// **********************************************************
	// *														*
	// *	This method dictates the GUI Layout of the Applet 	*
	// *														*
	// **********************************************************

	public void guiLayout()
	{

		//Where the GUI is created:
		JMenuBar menuBar;
		JMenu file, help;
		JMenuItem menuItem;
		JPanel welcome, files_local, files_server;
		JLabel Wlabel, Llabel, Slabel, about1;

		//Create the menu bar.
		menuBar = new JMenuBar();

		// *****************************************************

		//Create file menu.
		file = new JMenu("File");
		file.setMnemonic(KeyEvent.VK_A);
		file.getAccessibleContext().setAccessibleDescription(
		        "The only menu in this program that has menu items");
		menuBar.add(file);

			//Add Items to the file menu
			menuItem = new JMenuItem("Cut");
			file.add(menuItem);
			menuItem = new JMenuItem("Copy");
			file.add(menuItem);
			menuItem = new JMenuItem("Paste");
			file.add(menuItem);
			file.addSeparator();
			menuItem = new JMenuItem("Logout");
			file.add(menuItem);

		//Create help menu
		help = new JMenu("Help");
		menuBar.add(help);

			//Add Items to the help menu
			menuItem = new JMenuItem("Readme");
			help.add(menuItem);
			// help.addSeparator();  --- Separator
			menuItem = new JMenuItem("About Sting...");
			help.add(menuItem);
			menuItem.addActionListener(this);

		//Add the menu bar to the GUI
		setJMenuBar(menuBar);

		// *****************************************************

		// ------------------------------------------------

		// This section sets the three main layout panels in
		// positions top left and right.

		// The top "Welcome" panel
		welcome = new JPanel();
		welcome.setBackground(Color.white);
		getContentPane().add(welcome, BorderLayout.PAGE_START);
		Wlabel = new JLabel("Welcome <user> ...");
		welcome.add("West",Wlabel);

		// The left panel for local file handler
		files_local = new JPanel();
		files_local.setBackground(Color.red);
		getContentPane().add(files_local, BorderLayout.LINE_START);
		//Llabel = new JLabel("Local Files     ");
		//files_local.add(Llabel);

		//The right panel for server file Handler
		files_server = new JPanel();
		files_server.setBackground(Color.blue);
		getContentPane().add(files_server, BorderLayout.LINE_END);
		Slabel = new JLabel("Server Files      ");
		files_server.add(Slabel);

		// -------------------------------------------------

		JFileChooser chooser = new JFileChooser();
		files_local.add("Center", chooser);
		chooser.validate();

		// *****************************************************

	}


	public void actionPerformed(ActionEvent e)
	{
		JLabel about1, about2, about3, title;
		JPanel about;

		about1 = new JLabel("Sting SFTP...");
		about2 = new JLabel("Written By: Stephen Cheesley");
		about3 = new JLabel("Developed: 26/06/2006");
		about = new JPanel();

		about.setLayout(new BorderLayout());
		about.add("North", about1);
		about.add("Center",about2);
		about.add("South",about3);

		JOptionPane.showMessageDialog(getContentPane(),about,"Sting SFTP",JOptionPane.PLAIN_MESSAGE);
    }

}

That is the entirity of my code, however the main section that I tried for JFileChooser is......

		JFileChooser chooser = new JFileChooser();
		files_local.add("Center", chooser);
		chooser.validate();

[graviton]

well, that files_local.add("Center", chooser); will not work properly.
as far as i know, the filechoose creates it's own frame to display the chooser.
so you just have to instantiate it and not add to a component.
when you want the filechooser to display, you invoke the following method:
int returnVal = chooser.showOpenDialog(aComponent);
where aComponent is the parent component to which the chooser shall be the child.

suppose you have a button called fileselect, which will pop up the chooser (in fact you can use any actionPerformed method of any component, like menu items etc.). for aComponent i suggest you to use the applet itself. for this purpose you will need a reference to the applet itself. since "this" will not function in an actionlistener, which itself is a local object, you can store a reference in the init method:

public class Sting extends JApplet implements ActionListener{

  private Component me;
  
  public void init(){
     me = this;
     ...
  }
  ....

then while building the gui you will create the button fileselect and make a actionlistener:

fileselect.addActionListener(
  new ActionListener(){
    public void actionPerformed(...){
      int returnVal = chooser.showOpenDialog(me);
      if (returnVal == JFileChooser.APPROVE_OPTION) {
        File file = chooser.getSelectedFile();
        if (file!=null) // do sthng with file
      }
    }
  }
);

as you can see you don't add the chooser to any component, like you do with buttons. instead you give the chooser a parent component for display purposes when displaying.

[sc_3007]

Hey, i see what you are saying now, that totally makes sense. I am still having troubles though. I am trying to add it in to the files_local JPanel and I am still unsure as to how I am doing that from where I am now. This is my code, ammended after taking on board what you said:

/*
	***********************************
	Sting SFtp
	Creator: Stephen Cheesley
	Designer: Stephen Cheesley
	***********************************
*/

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

public class Sting extends JApplet implements ActionListener
{

	private Component me;

	//Methods to load on applet initialisation
	public void init()
	{
		try
		{
			javax.swing.SwingUtilities.invokeAndWait(new Runnable()
			{
				public void run()
				{
			    	guiLayout();
			    }
			});

		}
		catch (Exception e)
		{
			System.err.println("guiLayout didn't successfully complete");
		}

		me = this;
	}

	public void start()
	{

	}

	public void stop()
	{

	}


	// **********************************************************
	// *														*
	// *	This method dictates the GUI Layout of the Applet 	*
	// *														*
	// **********************************************************

	public void guiLayout()
	{

		//Where the GUI is created:
		JMenuBar menuBar;
		JMenu file, help;
		JMenuItem menuItem;
		final JPanel welcome, files_local, files_server;
		JLabel Wlabel, Llabel, Slabel, about1;
		JButton testButton;

		//Create the menu bar.
		menuBar = new JMenuBar();

		// *****************************************************

		//Create file menu.
		file = new JMenu("File");
		file.setMnemonic(KeyEvent.VK_A);
		file.getAccessibleContext().setAccessibleDescription(
		        "The only menu in this program that has menu items");
		menuBar.add(file);

			//Add Items to the file menu
			menuItem = new JMenuItem("Cut");
			file.add(menuItem);
			menuItem = new JMenuItem("Copy");
			file.add(menuItem);
			menuItem = new JMenuItem("Paste");
			file.add(menuItem);
			file.addSeparator();
			menuItem = new JMenuItem("Logout");
			file.add(menuItem);

		//Create help menu
		help = new JMenu("Help");
		menuBar.add(help);

			//Add Items to the help menu
			menuItem = new JMenuItem("Readme");
			help.add(menuItem);
			// help.addSeparator();  --- Separator
			menuItem = new JMenuItem("About Sting...");
			help.add(menuItem);
			menuItem.addActionListener(this);

		//Add the menu bar to the GUI
		setJMenuBar(menuBar);

		// *****************************************************

		// ------------------------------------------------

		// This section sets the three main layout panels in
		// positions top left and right.

		// The top "Welcome" panel
		welcome = new JPanel();
		welcome.setBackground(Color.white);
		getContentPane().add(welcome, BorderLayout.PAGE_START);
		Wlabel = new JLabel("Welcome <user> ...");
		welcome.add("West",Wlabel);
		testButton = new JButton("Test");
		welcome.add(testButton);

		// The left panel for local file handler
		files_local = new JPanel();
		files_local.setBackground(Color.red);
		getContentPane().add(files_local, BorderLayout.LINE_START);
		Llabel = new JLabel("Local Files     ");
		files_local.add(Llabel);

		//The right panel for server file Handler
		files_server = new JPanel();
		files_server.setBackground(Color.blue);
		getContentPane().add(files_server, BorderLayout.LINE_END);
		Slabel = new JLabel("Server Files      ");
		files_server.add(Slabel);

		// -------------------------------------------------

		final JFileChooser chooser = new JFileChooser();

		testButton.addActionListener(
			new ActionListener()
			{
		    	public void actionPerformed(ActionEvent e)
		    	{
		      		int returnVal = chooser.showOpenDialog(me);
		      		if (returnVal == JFileChooser.APPROVE_OPTION)
		      		{
		        		File file = chooser.getSelectedFile();
		        		if (file!=null)
		        		{}// do something with file
		      		}
		    	}
		  	});

		// *****************************************************

	}


	public void actionPerformed(ActionEvent e)
	{
		JLabel about1, about2, about3, title;
		JPanel about;

		about1 = new JLabel("Sting SFTP...");
		about2 = new JLabel("Written By: Stephen Cheesley");
		about3 = new JLabel("Developed: 26/06/2006");
		about = new JPanel();

		about.setLayout(new BorderLayout());
		about.add("North", about1);
		about.add("Center",about2);
		about.add("South",about3);

		JOptionPane.showMessageDialog(getContentPane(),about,"Sting SFTP",JOptionPane.PLAIN_MESSAGE);
    }

}

This is the relevant section for the ammended code:

		final JFileChooser chooser = new JFileChooser();

		testButton.addActionListener(
			new ActionListener()
			{
		    	public void actionPerformed(ActionEvent e)
		    	{
		      		int returnVal = chooser.showOpenDialog(me);
		      		if (returnVal == JFileChooser.APPROVE_OPTION)
		      		{
		        		File file = chooser.getSelectedFile();
		        		if (file!=null)
		        		{}// do something with file
		      		}
		    	}
		  	});

What I am struggling to comprehend is how from loading the Open Dialog into the me component do I get it into the relevant JPanel??

Many thanks for ur help, its really appreciated

[graviton]

when showing a filechooser, the only thing you can do is give it a parent component, which also may be a jpanel. but the chooser will pop up its own window, like JOptionPane.showMessageDialog(..) does. in fact message dialogs work nearly the same way, as you give them a parent component for display and relation purposes. so there is (to me) no known way to embed a filechooser into another component.
for now, your code seems to work properly.