Return a list of all fields including fields from parent in Java

/*  w  w  w  .  j a  v a  2  s  .c o m*/
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpServletResponse;
public class Main {

  public static void  main(String args[]) {
    System.out.println(Arrays.toString(getAllFields(String.class)));
  }
  public static Field[] getAllFields(Class<?> clazz)
  {
      List<Class<?>> classes = getAllSuperclasses(clazz);
      classes.add(clazz);
      return getAllFields(classes);
  }
  private static Field[] getAllFields(List<Class<?>> classes)
  {
      Set<Field> fields = new HashSet<Field>();
      for (Class<?> clazz : classes)
      {
          fields.addAll(Arrays.asList(clazz.getDeclaredFields()));
      }

      return fields.toArray(new Field[fields.size()]);
  }
  public static List<Class<?>> getAllSuperclasses(Class<?> clazz)
  {
      List<Class<?>> classes = new ArrayList<Class<?>>();

      Class<?> superclass = clazz.getSuperclass();
      while (superclass != null)
      {
          classes.add(superclass);
          superclass = superclass.getSuperclass();
      }

      return classes;
  }

}