Java Swing, On button click, output to JTextArea

Question

I have 2 classes one of which is a GUI.

My first class is called MusicSearch.java and it has this:

public static void directoryMusicLocator(File dir) {
    try 
    {
        String[] filetype = new String[] { "mp3" }; // only search mp3 files
        System.out.println("Getting all .mp3 files in " + dir.getCanonicalPath() + " including those in subdirectories");
        List<File> files = (List<File>) FileUtils.listFiles(dir, filetype, true);
        for (File file : files) 
        {
            System.out.println(file.getAbsolutePath()); // get the file's absolute path
        }
        System.out.println("\nFinished Searching.");
    }
    catch (IOException e) 
    {
        e.printStackTrace();
    }
}

What this does is that it searches for Mp3 files on a directory for example C:\\Music

For the GUI, well I created it using netbeans' JFrame Designer and a screenshot of this can be seen on the image below. (I can't embed images at the moment so I can only provide a link to the image.)

http://i.stack.imgur.com/7pLPL.jpg

On the JTextField next to the "Enter Location", the user enters a location for example C:\\Music. When the user clicks the button "Find MP3's" the method directoryMusicLocator is called. Below is the Action Listener for the Find MP3's button:

private void findMP3ButtonActionPerformed(java.awt.event.ActionEvent evt) {                                              
    // TODO add your handling code here:
    String fLocation = dirToSearch.getText(); // this gets the input from the textfield
    File dir = new File(fLocation); // converts the location to path
    MusicSearch.directoryMusicLocator(dir); 
}

An example of the output can be seen below when it is ran and user entered C:\\Music on the textfield:

C:\Music\Feint - Times Like These (Fracture Design Remix).mp3
C:\Music\Ficci - Climax (FREE).mp3
C:\Music\Ficci - Making Me Blue (FREE).mp3

Now what I want is the output to display on the JTextArea but I don't know how. Can someone tell me how.

Thanks

Answer 1

You just have to do the following changes in your directoryMusicLocator and findMP3ButtonActionPerformed methods. Instead of directly printing you just need to store the content in a StringBuilder and return that so that you can show it in the JTextArea .

public static String directoryMusicLocator(File dir) {
    try 
    {
        String[] filetype = new String[] { "mp3" }; // only search mp3 files
        StringBuilder outString = new StringBuilder("Getting all .mp3 files in " + dir.getCanonicalPath() + " including those in subdirectories\n");
        List<File> files = (List<File>) FileUtils.listFiles(dir, filetype, true);
        for (File file : files) 
        {
            outString.append(file.getAbsolutePath()+"\n"); // get the file's absolute path
        }
        outString.append("\nFinished Searching.");
        return outString.toString()
    }
    catch (IOException e) 
    {
        e.printStackTrace();
        return null;
    }
}

private void findMP3ButtonActionPerformed(java.awt.event.ActionEvent evt) {                                              
    // TODO add your handling code here:
    String fLocation = dirToSearch.getText(); // this gets the input from the textfield
    File dir = new File(fLocation); // converts the location to path
    String output = MusicSearch.directoryMusicLocator(dir); 

    // Replace <jTextArea> with your JTextArea field name
    <jTextArea>.setText(output);
}

Answer 2

JTextArea textArea = new JTextArea(); // instantiate the JTextArea

textArea.append("text"); // append to the existing text on JTextArea

textArea.setText("text"); // set the current text with the given one

hope this helps :)

Answer 3

Rather than calling System.out.println , which sends the output to the standard output steam, you should send it to the text area. But you can't do that without a reference to the JTextArea that you're working with, so you need to change the signature of directoryMusicLocator to include a JTextArea like so:

public static void directoryMusicLocator(File dir, JTextArea outputTextArea) {

Then, you'll want to change System.out.println(newText) to outputTextArea.append(newText + System.getProperty("line.separator")) . (Replace "newText" with the parameters that you're sending to the JTextArea.

Finally, change the call-sites for directoryMusicLocator(File) - pass a reference to the JTextArea : MusicSearch.directoryMusicLocator(dir, jTextArea1)