如何使用Java操作DOM？

Question

有没有什么方法可以获得一个DOM元素并对其进行操作，这样我就可以输入用户名和密码，以便在启动应用程序时自动登录？现在，我已经使用机器人让计算机传递我的登录信息并自动登录，但我需要一个更好的方法。非常感谢任何帮助！

import java.awt.AWTException;
import java.awt.Desktop;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.StringSelection;
import java.awt.event.KeyEvent;
import java.net.URL;

public class Main
{
private static String OS                = null;
private static Integer CTRL             = null;

private static String username          = "u1240430";
private static String password          = "123123";

public static void main(String[] args) {

    OS = System.getProperty("os.name");
    if( OS.equalsIgnoreCase("MAC OS X") ){
        CTRL = KeyEvent.VK_META;
    }else{
        CTRL = KeyEvent.VK_CONTROL;
    }


    try {
        Desktop.getDesktop().browse(new URL("https://awebsite.something/login.php").toURI());
        startWithLogin();
    } catch (Exception e){
        System.out.println(e.getMessage());
    }
}

private static void startWithLogin() {
    try {
        Robot r = new Robot();

        StringSelection selection = new StringSelection(username);
        Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
        clipboard.setContents(selection, null);

        r.delay(1500);

        r.keyPress(CTRL);
        r.keyPress(KeyEvent.VK_V);

        r.keyRelease(KeyEvent.VK_V);
        r.keyRelease(CTRL);

        r.delay(100);

        r.keyPress(KeyEvent.VK_TAB);
        r.keyRelease(KeyEvent.VK_TAB);

        r.delay(100);

        selection = new StringSelection(password);
        clipboard.setContents(selection, null);

        r.delay(100);

        r.keyPress(CTRL);
        r.keyPress(KeyEvent.VK_V);

        r.keyRelease(KeyEvent.VK_V);
        r.keyRelease(CTRL);

        r.delay(100);

        r.keyPress(KeyEvent.VK_ENTER);
        r.keyRelease(KeyEvent.VK_ENTER);

    } catch (AWTException ex) {
        System.out.println(ex.getMessage());
    }
  }
}