Java Code:
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class SampleInvoke {

  public static void main(String[] args) {
    String firstWord = "Hello ";
    String secondWord = "everybody.";
    String bothWords = append(firstWord, secondWord);
    System.out.println(bothWords);
  }

  public static String append(String firstWord, String secondWord) {
    String result = null;
    Class c = String.class;
    Class[] parameterTypes = new Class[] { String.class };
    Method concatMethod;
    Object[] arguments = new Object[] { secondWord };
    try {
      concatMethod = c.getMethod("concat", parameterTypes);
      result = (String) concatMethod.invoke(firstWord, arguments);
    } catch (NoSuchMethodException e) {
      System.out.println(e);
    } catch (IllegalAccessException e) {
      System.out.println(e);
    } catch (InvocationTargetException e) {
      System.out.println(e);
    }
    return result;
  }
}