java利用反射来调用一个类的私有方法和成员变量

因项目需要反射一个类的所有方法和成员，所以查了jdk文档，写了个测试程序

public class BeanUtils {

	public static void printMethods(String className)
			throws ClassNotFoundException {
		Class<?> classType = Class.forName(className);
		Method[] methods = classType.getDeclaredMethods();
		StringBuilder log = new StringBuilder();
		for (Method method : methods) {
			
			log.append(method.getReturnType().getName() + " " + method.getName());
			Class<?>[] parameterTypes = method.getParameterTypes();
			log.append("(");
			if (parameterTypes != null && parameterTypes.length > 0) {
				for (int i = 0; i < parameterTypes.length - 1; ++i) {
					Class<?> clas = parameterTypes[i];
					String parameterName = clas.getName();
					log.append(parameterName + ", ");
				}
				Class<?> clas = parameterTypes[parameterTypes.length - 1];
				String parameterName = clas.getName();
				log.append(parameterName);
			}
			log.append(")\n");
			
		}
		log.append("*****************************");
		System.out.println(log);
	}

	public static void printFields(String className)
			throws ClassNotFoundException {
		Class<?> classType = Class.forName(className);

		Field[] fields = classType.getDeclaredFields();
		StringBuilder log = new StringBuilder();
		for (Field field : fields) {
			// System.out.println(field);
			log.append(field.getName()).append("\n");
		}
		log.append("*****************************");
		System.out.println(log);
	}
}

public class BeanUtilsTest {

	@Test
	public void testPrintMethods() {
		String clsName = "java.lang.String";
		try {
			BeanUtils.printMethods(clsName);
			assertTrue(true);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			assertTrue(false);
		}
	}

	@Test
	public void testPrintFields() {
		String clsName = "java.lang.String";
		try {
			BeanUtils.printFields(clsName);
			assertTrue(true);
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			assertTrue(false);
		}
	}

}