PostProcessor

两个接口 BeanPostProcessor ，InstantiationAwareBeanPostProcessor。
InstantiationAwareBeanPostProcessor是BeanPostProcessor
`public class MyInstantiationPostProcessor implements InstantiationAwareBeanPostProcessor {

@Override<br />    **public **Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) **throws **BeansException {<br />        _/**<br />         *  执行时间在<br />         *<br />         *        // Give BeanPostProcessors a chance to return a proxy instead of the target bean instance.<br />         *           Object bean = resolveBeforeInstantiation(beanName, mbdToUse);<br />         *<br />         *  Object beanInstance = doCreateBean(beanName, mbdToUse, args);//这里真正得创建bean<br />         *             这个方法里有     -》instanceWrapper = createBeanInstance(beanName, mbd, args); 创建bean(调用了构造函数)<br />         *                             -》populateBean(beanName, mbd, instanceWrapper);  属性赋值<br />         *                              -》exposedObject = initializeBean(beanName, exposedObject, mbd); //初始化<br />         *<br />         *<br />         *<br />         */
    _System.**_out_**.println(**"postProcessBeforeInstantiation ------------------ InstantiationAwareBeanPostProcessor接口"**);<br />        **return null**;<br />    }
@Override<br />    **public boolean **postProcessAfterInstantiation(Object bean, String beanName) **throws **BeansException {
    _/**<br />         *  -》populateBean(beanName, mbd, instanceWrapper);  在 属性赋值一开始就执行了这个函数<br />         *      // Give any InstantiationAwareBeanPostProcessors the opportunity to modify the<br />         *        // state of the bean before properties are set. This can be used, for example,<br />         *        // to support styles of field injection.<br />         *        if (!mbd.isSynthetic() && hasInstantiationAwareBeanPostProcessors()) {<br />         *           for (InstantiationAwareBeanPostProcessor bp : getBeanPostProcessorCache().instantiationAware) {<br />         *              if (!bp.postProcessAfterInstantiation(bw.getWrappedInstance(), beanName)) {<br />         *                 return;<br />         *                                }*         }<br />         *        }<br />         *<br />         */
    _System.**_out_**.println(**"postProcessAfterInstantiation ------------------ InstantiationAwareBeanPostProcessor接口"**);
    **return false**;<br />    }
@Override<br />    **public **Object postProcessBeforeInitialization(Object bean, String beanName) **throws **BeansException {<br />        _/**<br />         * 在initializeBean 中得applyBeanPostProcessorsBeforeInitialization执行<br />         *  Object beanInstance = doCreateBean(beanName, mbdToUse, args);//这里真正得创建bean<br />         *             这个方法里有     -》instanceWrapper = createBeanInstance(beanName, mbd, args); 创建bean(调用了构造函数)<br />         *                             -》populateBean(beanName, mbd, instanceWrapper);  属性赋值<br />         *                              -》exposedObject = initializeBean(beanName, exposedObject, mbd); //初始化<br />         *                                   ->>>      wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);<br />         *                                               这里遍历所有得BeanPostProcessors<br />         */
    _System.**_out_**.println(**"postProcessBeforeInitialization ---------------------- BeanPostProcessor接口"**);<br />        **return null**;<br />    }
@Override<br />    **public **Object postProcessAfterInitialization(Object bean, String beanName) **throws **BeansException {<br />        _/**<br />         * 在initializeBean 中得applyBeanPostProcessorsBeforeInitialization执行<br />         *  Object beanInstance = doCreateBean(beanName, mbdToUse, args);//这里真正得创建bean<br />         *             这个方法里有     -》instanceWrapper = createBeanInstance(beanName, mbd, args); 创建bean(调用了构造函数)<br />         *                             -》populateBean(beanName, mbd, instanceWrapper);  属性赋值<br />         *                              -》exposedObject = initializeBean(beanName, exposedObject, mbd); //初始化<br />         *                                   ->>>            wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);<br />         *                                                       这里遍历所有得BeanPostProcessors<br />         *<br />         */<br />        _System.**_out_**.println(**"postProcessAfterInitialization ---------------------- BeanPostProcessor接口"**);
    **return null**;<br />    }<br />}

`