0.主要功能
- 注册el表达式解析器，
beanclassLoader，PropertyEditorRegistrar - 新增
ApplicationContextAwareProcessor(BeanPostProcessor，处理各种Aware接口的set方法调用) - 配置类型转化相关的
PropertyEditor - 设置被忽略的依赖注册（也就是属于这些接口的类型属性的不会注入任何
bean） - 注册一些组件为特殊依赖项，比如
beanFactory本身不会是一个bean，当一个bean需要的时候，如何注入。就是把这些依赖项 存在到一个缓存中 - 注册
Env bean
1. 代码流程解析
protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
// Tell the internal bean factory to use the context's class loader etc.
beanFactory.setBeanClassLoader(getClassLoader());
//设置el表达式解析器
beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver());
//新增一个propertyEditor注册中心(设置后，具体是在什么地方被调用，如何获取，怎么调用)
beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
// Configure the bean factory with context callbacks.
//配置BeanProcessor，用于在实现Aware接口的bean初始化后，调用器接口方法
beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
//Ignore the given dependency interface for autowiring
beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
beanFactory.ignoreDependencyInterface(EmbeddedValueResolverAware.class);
beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);
beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);
beanFactory.ignoreDependencyInterface(MessageSourceAware.class);
beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);
// BeanFactory interface not registered as resolvable type in a plain factory.
// MessageSource registered (and found for autowiring) as a bean.
//设置一些解析过的autowired对象,后续处理该类对象的autowire的时候,可以直接查询注入.不需要在从beanbectory中查找处理
beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
beanFactory.registerResolvableDependency(ResourceLoader.class, this);
beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
beanFactory.registerResolvableDependency(ApplicationContext.class, this);
// Detect a LoadTimeWeaver and prepare for weaving, if found.
if (beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
// Set a temporary ClassLoader for type matching.
beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
}
// Register default environment beans.
if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {
beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());
}
if (!beanFactory.containsLocalBean(SYSTEM_PROPERTIES_BEAN_NAME)) {
beanFactory.registerSingleton(SYSTEM_PROPERTIES_BEAN_NAME, getEnvironment().getSystemProperties());
}
if (!beanFactory.containsLocalBean(SYSTEM_ENVIRONMENT_BEAN_NAME)) {
beanFactory.registerSingleton(SYSTEM_ENVIRONMENT_BEAN_NAME, getEnvironment().getSystemEnvironment());
}
}
2. beanFactory.addPropertyEditorRegistrar()的使用
/*--org.springframework.beans.factory.support.AbstractBeanFactory--*/
public void addPropertyEditorRegistrar(PropertyEditorRegistrar registrar) {
Assert.notNull(registrar, "PropertyEditorRegistrar must not be null");
this.propertyEditorRegistrars.add(registrar);
}
this.propertyEditorRegistrar的定义如下
private final Set<PropertyEditorRegistrar> propertyEditorRegistrars =
new LinkedHashSet<PropertyEditorRegistrar>(4);
那么该属性会在什么时候调用呢？典型的用法在org.springframework.beans.factory.support.AbstractBeanFactory#registerCustomEditors.
protected void registerCustomEditors(PropertyEditorRegistry registry) {
PropertyEditorRegistrySupport registrySupport =
(registry instanceof PropertyEditorRegistrySupport ? (PropertyEditorRegistrySupport) registry : null);
..
if (!this.propertyEditorRegistrars.isEmpty()) {
for (PropertyEditorRegistrar registrar : this.propertyEditorRegistrars) {
try {
//addPropertyEditorRegistrar中增加的`PropertyEditorRegistrar`调用。
registrar.registerCustomEditors(registry);
}
catch (BeanCreationException ex) {
..
}
}
}
..
}
而registerCustomEditors方法会用来在 bean的 populate property的处理中，给BeanWrapper配置默认的propertyEditor。
/**--AbstractBeanFactory--**/
protected void initBeanWrapper(BeanWrapper bw) {
bw.setConversionService(getConversionService());
registerCustomEditors(bw);
}
protected BeanWrapper instantiateBean(final String beanName, final RootBeanDefinition mbd) {
try {
Object beanInstance;
final BeanFactory parent = this;
if (System.getSecurityManager() != null) {
...
}
else {
beanInstance = getInstantiationStrategy().instantiate(mbd, beanName, parent);
}
BeanWrapper bw = new BeanWrapperImpl(beanInstance);
initBeanWrapper(bw);
return bw;
}
catch (Throwable ex) {
...
}
}
在实例化instantiateBean后，随后的工作就是populate property
2.1PropertyEditorRegistrar 解析
PropertyEditorRegistrar的接口的目的是操作PropertyEditorRegistry,为其注入一些自定义的PropertyEditor,目的是避免重复代码，将各类默认的propertyEditor注入到各类PropertyEditorRegistry,为功能接口，定义如下。
public interface PropertyEditorRegistrar {
void registerCustomEditors(PropertyEditorRegistry registry);
}
参考实现ResourceEditorRegistrar,.
public void registerCustomEditors(PropertyEditorRegistry registry) {
ResourceEditor baseEditor = new ResourceEditor(this.resourceLoader, this.propertyResolver);
doRegisterEditor(registry, Resource.class, baseEditor);
doRegisterEditor(registry, ContextResource.class, baseEditor);
doRegisterEditor(registry, InputStream.class, new InputStreamEditor(baseEditor));
doRegisterEditor(registry, InputSource.class, new InputSourceEditor(baseEditor));
doRegisterEditor(registry, File.class, new FileEditor(baseEditor));
doRegisterEditor(registry, URL.class, new URLEditor(baseEditor));
ClassLoader classLoader = this.resourceLoader.getClassLoader();
doRegisterEditor(registry, URI.class, new URIEditor(classLoader));
doRegisterEditor(registry, Class.class, new ClassEditor(classLoader));
doRegisterEditor(registry, Class[].class, new ClassArrayEditor(classLoader));
if (this.resourceLoader instanceof ResourcePatternResolver) {
doRegisterEditor(registry, Resource[].class,
new ResourceArrayPropertyEditor((ResourcePatternResolver) this.resourceLoader, this.propertyResolver));
}
}
2.3 如何注入自定义的propertyEditor
使用CustomEditorConfigurer类，该类实现BeanFactoryPostProcessor，再beanFactory加载完成后，执行将自定义的propertyEditor注册到beanFactory中。
