java反射-第3篇

例子

通过反射动态给对象赋值

   @Test
    public void testd() throws Exception {
        Map<Object, Object> map = new HashMap<>();
        map.put("name", "张三");
        map.put("age", 18);
        User user = new User();
        reflectValue(map, user);
        System.out.println(user.toString());
    }
     //通过反射动态给对象赋值
    public Object reflectValue(Map<Object, Object> map, Object bean) throws Exception {
        Class<?> cls = bean.getClass();
        Method[] methods = cls.getDeclaredMethods();//获取该类所有的方法
        Field[] fields = cls.getDeclaredFields();//获取该类所有的属性
        for (Field field : fields) {
            String fieldName = field.getName();
            Object value = map.get(fieldName);
            if (value == null) {
                continue;
            }
            String setMethod = "set" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
            if (!checkMethod(setMethod, methods)) {
                continue;
            }
            Method method = cls.getMethod(setMethod, field.getType());
            method.setAccessible(true);//关闭安全检查
            method.invoke(bean, value);
        }
        return bean;
    }
     //检查方法是否存在
    private boolean checkMethod(String setMethod, Method[] methods) {
        for (Method m : methods) {
            if (setMethod.equals(m.getName())) {
                return true;
            }
        }
        return false;
    }