Java反射

 @Test
    void contextLoads() {
        List list = new ArrayList ();
        list.add("aa");
        list.add("bb");
        list.add("cc");
        list.add("dd");

        User user=new User();
        user.setPassword ( "666" );
        Class <? extends User> a = user.getClass ( );
        try {
            Field u = a.getDeclaredField ( "password" );
            u.setAccessible ( true );
            try {
                String o = (String)u.get ( user );
                System.out.println ( "未修改的密码是====="+o +"==========");
            } catch (IllegalAccessException e) {
                e.printStackTrace ( );
            }

            try {
                u.set ( user,"123" );
                String o = (String)u.get ( user );
                System.out.println ( "修改后的密码是====="+o +"==========");
            } catch (IllegalAccessException e) {
                e.printStackTrace ( );
            }

            // 获取bean信息  
            BeanInfo beanInfo = null;
            try {
                beanInfo = Introspector.getBeanInfo(User.class);
            } catch (IntrospectionException e) {
                e.printStackTrace ( );
            }
         /*   // 获取bean的所有属性列表
            PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors ( );
            for (PropertyDescriptor p:propertyDescriptors) {
                System.out.println ( "+++++++" + p );
            }*/

            // 获取bean的所有属性列表
            PropertyDescriptor[] property = beanInfo.getPropertyDescriptors ( );
            for (PropertyDescriptor p:property) {
                System.out.println ( "+++++++" + p.getName () );
                System.out.println ( "+++++++" + p.getPropertyType () );
                System.out.println ( "+++++++" + p.getReadMethod () );
                System.out.println ( "+++++++" + p.getWriteMethod () );
                Method readMethod = p.getReadMethod ( );
                try {
                    Object o = readMethod.invoke ( user );
                    System.out.println ( "=======该对象的读方法是"+o );
                } catch (IllegalAccessException e) {
                    e.printStackTrace ( );
                } catch (InvocationTargetException e) {
                    e.printStackTrace ( );
                }
           
            }

        } catch (NoSuchFieldException e) {
            e.printStackTrace ( );
        }

    }