transferring class JTextArea to main class JTextArea

public class SimpleWebCrawler extends JFrame {

static JTextArea _resultArea = new JTextArea(200, 200);
    JScrollPane scrollingArea = new JScrollPane(_resultArea);
    private final static String newline = "\n";

 public SimpleWebCrawler() throws MalformedURLException {


        _resultArea.setEditable(false);
        System.out.println("Please enter the website  :");
        Scanner scan2 = new Scanner(System.in);
        String word2 = scan2.nextLine();

        try {
            URL my_url = new URL("http://" + word2 + "/");
            BufferedReader br = new BufferedReader(new InputStreamReader(
                    my_url.openStream()));
            String strTemp = "";
            while (null != (strTemp = br.readLine())) {
                _resultArea.append(strTemp + newline);
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        JPanel content = new JPanel();
        content.setLayout(new BorderLayout());
        content.add(scrollingArea, BorderLayout.CENTER);

        this.setContentPane(content);
        this.setTitle("Crawled Links");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        this.pack();

public static void main(String[] args) throws IOException {



        JFrame win = new SimpleWebCrawler();
        win.setVisible(true);

    }
}

This class extracts URL from a website and display the output in a JTextArea.

public class Main {

    private static void createAndShowGUI()  {

        JFrame frame1 = new JFrame("FINAL YEAR PROJECT VER 1.0");
        JTextArea test = new JTextArea(200, 200);
        frame1.setSize(500,500);
        frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame1.add(test);

        FlowLayout experimentLayout = new FlowLayout();
        experimentLayout.setAlignment(FlowLayout.CENTER);
        frame1.setLayout(experimentLayout);



        JButton button = new JButton("Extract Links");
 button.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e)
         开发者_JS百科   {
                try {
                    SimpleWebCrawler.main(null);

                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            }
        });      

 frame1.getContentPane().add(button);

public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

This class is the main class with the GUI. It has a button to call the other class to execute the code. Now the question is, i am putting a JTextArea on this main class frame. How do i transfer the above class outputs to this class JTextArea ?

You have a main inside the constructor in SimpleWebCrawler and another one inside createAndShowGUI in the Main.

1. You can not have two main methods in one application.

2. In Java you can not put a method inside another one.

3. public SimpleWebCrawler() throws MalformedURLException, and you have a try-catch inside as well.

4. SimpleCrawler will work if you add a closing bracket '}', right before public static void main.

like here...

   this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   this.pack();
}
public static void main(String[] args) throws IOException {
   JFrame win = new SimpleWebCrawler();
   win.setVisible(true);
}

You do not need the Main class at all. The JTextArea is in SimpleWebCrawler. You need to add your logic there.

In order to turn this into a web-crawler you can get the HTML from your _resultArea JTextArea, process it and pass and display the results to a modal JDialog with another JTextArea, or add a second JTextArea next to the one you have in the same JFrame.