java反射应用

反射

使用JAVA反应进行两个vo有相同字段名字进行子转换：

@Test
    public void doTransTest() {
        A a= new A();
        A.setC(111L);

        B b= new B();
        doTrans(a, b);
    }

    /**
    *@param sour 来源vo
    *@param dest 待转换vo
    */
    public void doTrans(Object sour, Object dest) {
        if (sour == null) {
            dest = null;
            return;
        }
    //反射原理应用
        Class<?> sourceClass = sour.getClass();
        Class<?> destClass = dest.getClass();
        for (Field field : sourceClass.getDeclaredFields()) {

            String fieldName = field.getName();
            Object value;

            if (fieldName.equals("serialVersionUID")) {
                continue;
            }

            try {
                PropertyDescriptor propertyDescriptor = new PropertyDescriptor(fieldName, sourceClass);
                value = propertyDescriptor.getReadMethod().invoke(sour);
            } catch (Exception e) {
                //log
                continue;
            }

            if (value == null) {
                continue;
            }
            try {
                PropertyDescriptor propertyDescriptor = new PropertyDescriptor(fieldName, destClass);
                propertyDescriptor.getWriteMethod().invoke(dest, value);
            } catch (Exception e) {
                //log
                continue;
            }
        }
    }

SpringIOC反射的应用：

/**
    * springIOC和反射test
    *
    * @throws Exception
    */
   @Test
   public void reflexTest() throws Exception {

       /**
        * 第一步，springIOC解析如下bean
        *  <bean id="cartBean" class="com.mmall.pojo.Cart"></bean>
        */
       //解析bean字符串xxxxx
       String beanId = "cartBean";
       String beanClass = "com.mmall.pojo.Cart";
       Class<?> cls = Class.forName(beanClass);
       Object object = cls.newInstance();
       //模拟spring容器
       Map container = Maps.newHashMap();
       //bean注入spring容器,实例化成功
       container.put(beanId, object);


       /**
        * 第二步：模拟ref注入
        *      <bean id="cartBean" class="com.mmall.pojo.Cart"></bean>
        *          <property name="user" ref="userBean"></property>
        *      <bean>
        */
       //初始化refBean(userBean)
       String beanIdUser = "cartBean";
       String beanClassUser = "com.mmall.pojo.User";
       Class<?> clsUser = Class.forName(beanClassUser);
       Object objectUser = clsUser.newInstance();
       //并注入spring容器
       container.put(beanIdUser,objectUser);

       //得到cartBean的setUser方法
       String setUserName = "setUser";
       Object paramBean = container.get(beanIdUser);
       //cls是cart对象
       Method setter = cls.getMethod(setUserName, objectUser.getClass());
       //注入set方法
       setter.invoke(object, paramBean);
   }

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