Update JTextArea to show progress

Question

I am doing an application to zip and delete files. So far I've managed to implement the SwingWorker but it doesn't show and update the TextArea. The results are only shown in the console. Could someone tell me with an example what I am doing wrong or what am I missing? The code I've made is the shown below:

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.zip.*;
import javax.swing.*;
import java.util.List;

@SuppressWarnings("serial")
public class zipfiles2 extends JFrame {
static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
private File datei, parent;
private String name;

class Task extends SwingWorker<String, String>
{
  String status;
  JTextArea statusprocess;

  public Task(JTextArea statusprocess)
  {
      this.statusprocess = statusprocess;
  }
  private String addToZip(String path, String srcFile, ZipOutputStream zipOut) throws IOException
  {        
    File file = new File(srcFile);
    String filePath = "".equals(path) ? file.getName() : path + "/" + file.getName();
    if (file.isDirectory()) 
    {
      for (String fileName : file.list()) 
      {
        status = "Folder: "+srcFile + "/" +" is being added to the zip file";
        addToZip(filePath, srcFile + "/" + fileName, zipOut);
      }
    } 
    else 
    {
        if (new File(filePath).canRead())
        {
            status = "File "+filePath+"is being zipped";
        }
        else
        {
            status = "File: "+filePath+" is being zipped";
            zipOut.putNextEntry(new ZipEntry(filePath));

            FileInputStream in = null;
            try {
                    in = new FileInputStream(srcFile);
            } catch (FileNotFoundException e) {
                new File(srcFile).delete();
            }

            byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
            int len;
            while ((len = in.read(buffer)) != -1) {
                zipOut.write(buffer, 0, len);
            }
            in.close();
        }
    }
    return status;
  }

public String zipFile(String fileToZip, String zipFile, boolean excludeContainingFolder) throws IOException
  {        
      ZipOutputStream zipOut = new ZipOutputStream(new FileOutputStream(zipFile));    
      File srcFile = new File(fileToZip);

      if(excludeContainingFolder && srcFile.isDirectory()) 
      {
          for(String fileName : srcFile.list()) 
          {
                addToZip("", fileToZip + "/" + fileName, zipOut);
          }
       } 
       else 
       {
           addToZip("", fileToZip, zipOut);
       }
       zipOut.flush();
       zipOut.close();
       status = "The zip file " + zipFile + " was created successfully";
       return status;
  }
  public String deleteDirectory(File f) throws IOException  {
        if (f.isDirectory()) {
            for (File c: f.listFiles()) {
                status= "File: "+c.getName()+" is being deleted"; 
                deleteDirectory(c);
            }
            f.delete();
        }
        else 
        {
            f.delete();
        }
        return status;

  }
@Override
protected String doInBackground() throws Exception {
    zipFile(datei.getAbsolutePath(), parent.getAbsolutePath()+"/"+name, true);
    publish(status);
    deleteDirectory(datei);
    publish(status);
    return status;
}

@Override
protected void process(List<String> chunks)
{
    for (String status : chunks) {
        statusprocess.append(status);
    }
}
 }
 public zipfiles2() {

  JFileChooser browser = new JFileChooser();
  browser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
  JPanel panel = new JPanel();
  final JTextArea showprogress = new JTextArea();

  ActionListener fileValidation = new ActionListener()
  {
    public void actionPerformed(ActionEvent actionEvent)
    {
        JFileChooser browser2 = (JFileChooser) actionEvent.getSource();
        String command = actionEvent.getActionCommand();

        if (command.equals(JFileChooser.APPROVE_SELECTION))
        {
            datei = browser2.getSelectedFile();
            parent = browser2.getCurrentDirectory();
            File[] dio = parent.listFiles();

            if (datei.isFile()) { name = datei.getName().substring(0, datei.getName().lastIndexOf("."))+".zip"; }
            else { name = datei.getName()+".zip"; }

            for (File dateien: dio)
            {   
                if (dateien.isFile() && dateien.getName().endsWith(".zip"))
                {
                   if (name.equals(dateien.getName())) 
                   {
                       JOptionPane.showMessageDialog(null,"Eine Zip-Datei mit der Name der ausgewählten Datei existiert bereits im Ordner", "Validierung", JOptionPane.WARNING_MESSAGE);
                       new zipfiles2().setVisible(true);
                   }
                }
            }
            Task task = new Task(showprogress);
            task.execute();
         } 
         else
         {
            System.exit(0);  
         }
      }

  };

  browser.addActionListener(fileValidation);


  JProgressBar progessbar = new JProgressBar();
  progressbar.setIndeterminate(true);
  panel.add(progressbar);
  panel.add(showprogress);

  Dimension ScS = Toolkit.getDefaultToolkit().getScreenSize();
  this.setTitle("Zip Tool");
  this.setSize(200, 90);
  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  this.setLocation(ScS.width/2 - this.getSize().width/2, ScS.height/2 - this.getSize().height/2);

  browser.showOpenDialog(this);
  this.add(panel, BorderLayout.PAGE_START);
}
 public static void main(String[] args) {
     java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                try 
                {
                    UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");     
                } 
                catch (Exception ex) 
                {
                    ex.printStackTrace();
                }
                new zipfiles2().setVisible(true);
            }
        });
  }
}

EDIT: The code above is a new version, with the corrections suggested. However, it doesn't show my GUI yet. Am I still missing something?

SECOND EDIT: My GUI is shown but my textarea is not being updated. How should I pass the statuses from the other methods to the doInBackground method in order to publish? Maybe an ArrayList type String?

Answer 1

You are not correctly overriding the process method , the signature is like :

protected void process(List<V> chunks)

in your case it would be :

protected void process(List<String> chunks)

Using the @Override annotation would have prevented this problem .

Then, you would use it that way :

     @Override
     protected void process(List<String> chunks) {
         for (String status : chunks) {
             statusprocess.append(status);
         }
     }