spring——AOP原理及源码（四）

 1 @Override
 2     public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {
 3         Object cacheKey = getCacheKey(beanClass, beanName);
 4 
 5         if (beanName == null || !this.targetSourcedBeans.contains(beanName)) {
 6             if (this.advisedBeans.containsKey(cacheKey)) {
 7                 return null;
 8             }
 9             if (isInfrastructureClass(beanClass) || shouldSkip(beanClass, beanName)) {
10                 this.advisedBeans.put(cacheKey, Boolean.FALSE);
11                 return null;
12             }
13         }
14 
15         // Create proxy here if we have a custom TargetSource.
16         // Suppresses unnecessary default instantiation of the target bean:
17         // The TargetSource will handle target instances in a custom fashion.
18         if (beanName != null) {
19             TargetSource targetSource = getCustomTargetSource(beanClass, beanName);
20             if (targetSource != null) {
21                 this.targetSourcedBeans.add(beanName);
22                 Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(beanClass, beanName, targetSource);
23                 Object proxy = createProxy(beanClass, beanName, specificInterceptors, targetSource);
24                 this.proxyTypes.put(cacheKey, proxy.getClass());
25                 return proxy;
26             }
27         }
28 
29         return null;
30     }

 1 /**
 2      * Wrap the given bean if necessary, i.e. if it is eligible for being proxied.
 3      * @param bean the raw bean instance
 4      * @param beanName the name of the bean
 5      * @param cacheKey the cache key for metadata access
 6      * @return a proxy wrapping the bean, or the raw bean instance as-is
 7      */
 8     protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
 9         if (beanName != null && this.targetSourcedBeans.contains(beanName)) {
10             return bean;
11         }
12         if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {
13             return bean;
14         }
15         if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {
16             this.advisedBeans.put(cacheKey, Boolean.FALSE);
17             return bean;
18         }
19 
20         // Create proxy if we have advice.
21         Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);
22         if (specificInterceptors != DO_NOT_PROXY) {
23             this.advisedBeans.put(cacheKey, Boolean.TRUE);
24             Object proxy = createProxy(
25                     bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));
26             this.proxyTypes.put(cacheKey, proxy.getClass());
27             return proxy;
28         }
29 
30         this.advisedBeans.put(cacheKey, Boolean.FALSE);
31         return bean;
32     }

 1 /**
 2      * Create an AOP proxy for the given bean.
 3      * @param beanClass the class of the bean
 4      * @param beanName the name of the bean
 5      * @param specificInterceptors the set of interceptors that is
 6      * specific to this bean (may be empty, but not null)
 7      * @param targetSource the TargetSource for the proxy,
 8      * already pre-configured to access the bean
 9      * @return the AOP proxy for the bean
10      * @see #buildAdvisors
11      */
12     protected Object createProxy(
13             Class<?> beanClass, String beanName, Object[] specificInterceptors, TargetSource targetSource) {
14 
15         if (this.beanFactory instanceof ConfigurableListableBeanFactory) {
16             AutoProxyUtils.exposeTargetClass((ConfigurableListableBeanFactory) this.beanFactory, beanName, beanClass);
17         }
18 
19         ProxyFactory proxyFactory = new ProxyFactory();
20         proxyFactory.copyFrom(this);
21 
22         if (!proxyFactory.isProxyTargetClass()) {
23             if (shouldProxyTargetClass(beanClass, beanName)) {
24                 proxyFactory.setProxyTargetClass(true);
25             }
26             else {
27                 evaluateProxyInterfaces(beanClass, proxyFactory);
28             }
29         }
30 
31         Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
32         proxyFactory.addAdvisors(advisors);
33         proxyFactory.setTargetSource(targetSource);
34         customizeProxyFactory(proxyFactory);
35 
36         proxyFactory.setFrozen(this.freezeProxy);
37         if (advisorsPreFiltered()) {
38             proxyFactory.setPreFiltered(true);
39         }
40 
41         return proxyFactory.getProxy(getProxyClassLoader());
42     }

 1 @Override
 2     public void refresh() throws BeansException, IllegalStateException {
 3         synchronized (this.startupShutdownMonitor) {
 4             // Prepare this context for refreshing.
 5             prepareRefresh();
 6 
 7             // Tell the subclass to refresh the internal bean factory.
 8             ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();
 9 
10             // Prepare the bean factory for use in this context.
11             prepareBeanFactory(beanFactory);
12 
13             try {
14                 // Allows post-processing of the bean factory in context subclasses.
15                 postProcessBeanFactory(beanFactory);
16 
17                 // Invoke factory processors registered as beans in the context.
18                 invokeBeanFactoryPostProcessors(beanFactory);
19 
20                 // Register bean processors that intercept bean creation.
21                 registerBeanPostProcessors(beanFactory);
22 
23                 // Initialize message source for this context.
24                 initMessageSource();
25 
26                 // Initialize event multicaster for this context.
27                 initApplicationEventMulticaster();
28 
29                 // Initialize other special beans in specific context subclasses.
30                 onRefresh();
31 
32                 // Check for listener beans and register them.
33                 registerListeners();
34 
35                 // Instantiate all remaining (non-lazy-init) singletons.
36                 finishBeanFactoryInitialization(beanFactory);
37 
38                 // Last step: publish corresponding event.
39                 finishRefresh();
40             }
41 
42             catch (BeansException ex) {
43                 if (logger.isWarnEnabled()) {
44                     logger.warn("Exception encountered during context initialization - " +
45                             "cancelling refresh attempt: " + ex);
46                 }
47 
48                 // Destroy already created singletons to avoid dangling resources.
49                 destroyBeans();
50 
51                 // Reset ‘active‘ flag.
52                 cancelRefresh(ex);
53 
54                 // Propagate exception to caller.
55                 throw ex;
56             }
57 
58             finally {
59                 // Reset common introspection caches in Spring‘s core, since we
60                 // might not ever need metadata for singleton beans anymore...
61                 resetCommonCaches();
62             }
63         }
64     }