用不同的参数在不同的地方叫秋千工人

Question

I am using swing worker to validate files, I want the startLine and endLine to be sent to the validate class as i do not want to validate the whole file every time. For the first time when an existing file is openend, i want to send the startLine as 0 and endLine as endLine = editorTextArea.getLineCount() - 1;. After that i should be able to send the startLine and endLine to my convenience every second. How do i achieve this?

Validate class:

  class Validate implements Runnable {

     private JTextArea editorTextArea;
     private JTextArea errorTextArea;
     private int startLine;
     private int endLine;

     public Validate(JTextArea editor, JTextArea error, startLine, endLine) {
         this.editorTextArea = editor;
         this.errorTextArea  = error;
         this.startLine = startLine;
         this.endLine = endLine;        
    }

@Override
public void run() {
    SwingWorker worker = new SwingWorker<Void, Void>() {
        @Override
        protected Void doInBackground() throws Exception {
            //CODE TO VALIDATE
            return null;
        }

        @Override
        protected void done() {                
            //CODE TO DISPLAY THE RESULT
        }
    };
    worker.execute();
    }
 }

Main class:

  //Calls the validate
   public void taskExecutor() {               
          ScheduledExecutorService scheduler =
                 Executors.newSingleThreadScheduledExecutor();
           final ScheduledFuture<?> timeHandle =
                 scheduler.scheduleAtFixedRate(new Validate(editorTextArea,   errorTextArea), 0, 1, SECONDS);                 
}


    private void openFileActionPerformed(java.awt.event.ActionEvent evt)      {                                      

  fileChooser.setCurrentDirectory(new File(".txt"));
int result = fileChooser.showOpenDialog(new JPanel());
int totLines = 0;
String[] content = null;

if (result == JFileChooser.APPROVE_OPTION) {
    try {
        filename = String.valueOf(fileChooser.getSelectedFile());
        setTitle(filename);

        FileReader fr = new FileReader(filename);
        editorTextArea.read(fr, null);
        fr.close();
        startLine = 0;
        endLine = editorTextArea.getLineCount() - 1;
        //here i want to call the validate class once. that is askExecutor();                
    } catch (IOException ex) {
        System.out.println(ex);
    }
}
}

Answer 1

A SwingWorker uses an ExecutorService internally, but the worker "is only designed to be executed once." I don't see why you're wrapping the worker in a Runnable that's scheduled at a fixed rate. Instead, execute() the task once and let it publish() interim results that can be process() ed on the EDT. For line numbers, SwingWorker<Boolean, Integer> may be appropriate. Integer would represent the last line number processed, while Boolean would represent the final validation result returned by doInBackground() .

If the user is aynchronously selecting multiple files for validation, consider adding each executing worker to a suitable TableModel and displaying the results in the corresponding JTable . @mKorbel has shown several examples featuring JProgressBar .

Addendum: If you're validating additions to the JTextArea , you'll want to execute() a new worker each time, passing the new range of line numbers as parameters to the worker's constructor. This example , which passes a single int count , may suggest the approach. The trigger can be a java.util.Timer , a javax.swing.Timer or even the ScheduledExecutorService you originally proposed.