spring复习：（30）CachedIntrospectionResults类

可以给这个类的构造方法传递一个class对象，

	private CachedIntrospectionResults(Class beanClass) throws BeansException {
		try {
			if (logger.isTraceEnabled()) {
				logger.trace("Getting BeanInfo for class [" + beanClass.getName() + "]");
			}
			this.beanInfo = getBeanInfo(beanClass);

			if (logger.isTraceEnabled()) {
				logger.trace("Caching PropertyDescriptors for class [" + beanClass.getName() + "]");
			}
			this.propertyDescriptorCache = new LinkedHashMap<>();

			// This call is slow so we do it once.
			PropertyDescriptor[] pds = this.beanInfo.getPropertyDescriptors();
			for (PropertyDescriptor pd : pds) {
				if (Class.class == beanClass &&
						("classLoader".equals(pd.getName()) ||  "protectionDomain".equals(pd.getName()))) {
					// Ignore Class.getClassLoader() and getProtectionDomain() methods - nobody needs to bind to those
					continue;
				}
				if (logger.isTraceEnabled()) {
					logger.trace("Found bean property '" + pd.getName() + "'" +
							(pd.getPropertyType() != null ? " of type [" + pd.getPropertyType().getName() + "]" : "") +
							(pd.getPropertyEditorClass() != null ?
									"; editor [" + pd.getPropertyEditorClass().getName() + "]" : ""));
				}
				pd = buildGenericTypeAwarePropertyDescriptor(beanClass, pd);
				this.propertyDescriptorCache.put(pd.getName(), pd);
			}

			// Explicitly check implemented interfaces for setter/getter methods as well,
			// in particular for Java 8 default methods...
			Class currClass = beanClass;
			while (currClass != null && currClass != Object.class) {
				introspectInterfaces(beanClass, currClass);
				currClass = currClass.getSuperclass();
			}

			this.typeDescriptorCache = new ConcurrentReferenceHashMap<>();
		}
		catch (IntrospectionException ex) {
			throw new FatalBeanException("Failed to obtain BeanInfo for class [" + beanClass.getName() + "]", ex);
		}
	}

构造出该类的对象后可以从该对象中获取类的元数据信息