public class AppTest {

    private NodeClass nodeClass;

    public static String  hehe = "hehe";

    public String xixi = "xixi";

    public void test() {

        Field[] fields = AppTest.class.getDeclaredFields();

        try {

            for (Field field : fields) {

                field.setAccessible(true);

                if(field.getType().toString().endsWith("java.lang.String") && Modifier.isStatic(field.getModifiers()))

                    System.out.println(field.getName() + " , " + field.get(AppTest.class));

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

}