import javax.swing.*;
import java.awt.event.ActionEvent;
import java.io.*;

public class TestOpenByWindows {
   public static void main(String[] args) throws FileNotFoundException {
      final File file = new File(System.getProperty("java.io.tmpdir"), "myFile.txt");
      PrintWriter writer = new PrintWriter(new FileOutputStream(file));
      try {
         writer.println("Hello Notepad!");
      } finally {
         writer.close();
      }

      final JFrame frame = new JFrame("Text open");
      frame.getContentPane().add(
         new JButton(
            new AbstractAction("Open ME!") {
               public void actionPerformed(ActionEvent actionEvent) {
                  try {
                     Runtime.getRuntime().exec(new String[] {"cmd.exe", "/C", "start", file.getAbsolutePath()});
                  } catch (IOException e) {
                     JOptionPane.showMessageDialog(frame, String.valueOf(e), "IO error", JOptionPane.ERROR_MESSAGE);
                  }
               }
            }
         )
      );
      frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
      frame.pack();
      frame.setVisible(true);
   }
}