Exception while invoking created method

I've just created method and wrote it to the JAR file, now I want to invoke it and it keeps giving me NoSuchMethodException. What is wrong with the code below? Declarations (global):

private static String newMethodBody="";
    private static CtClass ctClass;
        private static String newMethodBody="";
        private static CtMethod ctMethod;

This is how I create method:

private static void createMethod() throws CannotCompileException, NotFoundException, IOException {
    JTextArea JTextArea = new JTextArea(50,50);

    StringBuilder sb = new StringBuilder(64);
        sb.append("   public static void TestHelloWorld() {\n");
        sb.append("   System.out.println(\"New example method\"); } \n");
        newMethodBody = sb.toString();

        JTextArea.setText(newMethodBody);
        String[] options = {"OK"};
        int selectedOption = JOptionPane.showOptionDialog(null, JTextArea, null, JOptionPane.NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, options , options[0]);
        if(selectedOption == 0)
        {   try {
            newMethodBody = JTextArea.getText();
            CtMethod newmethod;
            newmethod = CtNewMethod.make(JTextArea.getText(), ctClass);
            ctClass.addMethod(newmethod);
            ctClass.writeFile();
            }
            catch(CannotCompileException e) {
                JOptionPane.showMessageDialog(null, "Can't compile file");
                JOptionPane.showMessageDialog(null, e);
            }}}

That's how I want to execute it:

 private static void createAndExecuteMethod() throws ClassNotFoundException,InstantiationException, IllegalAccessException,NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException, MalformedURLException, NotFoundException 

{
    File file = new File(path); 
    URL url = file.toURI().toURL();
    URL[] urls = new URL[] { url };
    ClassLoader cl = new URLClassLoader(urls);
    Class loadedClass = cl.loadClass(ctClass.getName());
    Object createdObject = loadedClass.newInstance();
    Method method = loadedClass.getDeclaredMethod(ctMethod.getName(), loadedClass);
    method.invoke(createdObject);

}