Spring 启动记录（2）

摘要: 继续到XmlWebApplicationContext初始化，父类DefualtResourceLoader、AbstractApplicationContext、AbstractRefreshableApplicationContext初始化

Spring MVC 启动记录（2）
1、XmlWebApplicationContext



继承图看出最顶层的依次之下 DefaultResouceLoader



AbstractApplicationContext



AbstractRefreshableApplicationContext



AbstractRefreshableConfigApplicationContext



AbstractRefreshableWebApplicationContext



最后是XmlWebApplicationContext
2、DefaultResourceLoader是一个单纯的资源加载的默认实现类

public class DefaultResourceLoader implements ResourceLoader {

private ClassLoader classLoader;

/**
* Create a new DefaultResourceLoader.
* <p>ClassLoader access will happen using the thread context class loader
* at the time of this ResourceLoader's initialization.
* @see java.lang.Thread#getContextClassLoader()
*/
public DefaultResourceLoader() {
this.classLoader = ClassUtils.getDefaultClassLoader();
}

/**
* Create a new DefaultResourceLoader.
* @param classLoader the ClassLoader to load class path resources with, or {@code null}
* for using the thread context class loader at the time of actual resource access
*/
public DefaultResourceLoader(ClassLoader classLoader) {
this.classLoader = classLoader;
}

/**
* Specify the ClassLoader to load class path resources with, or {@code null}
* for using the thread context class loader at the time of actual resource access.
* <p>The default is that ClassLoader access will happen using the thread context
* class loader at the time of this ResourceLoader's initialization.
*/
public void setClassLoader(ClassLoader classLoader) {
this.classLoader = classLoader;
}

/**
* Return the ClassLoader to load class path resources with.
* <p>Will get passed to ClassPathResource's constructor for all
* ClassPathResource objects created by this resource loader.
* @see ClassPathResource
*/
@Override
public ClassLoader getClassLoader() {
return (this.classLoader != null ? this.classLoader : ClassUtils.getDefaultClassLoader());
}

@Override
public Resource getResource(String location) {
Assert.notNull(location, "Location must not be null");
//如果路径是/开始的则new ClassPathContextResource(path, getClassLoader())
if (location.startsWith("/")) {
return getResourceByPath(location);
}
//以classpath:开始把classpath:去掉后new ClassPathContextResource
else if (location.startsWith(CLASSPATH_URL_PREFIX)) {
return new ClassPathResource(location.substring(CLASSPATH_URL_PREFIX.length()), getClassLoader());
}
//看来/开始的跟classpath:开始的处理都是ClassPathResource资源
else {
try {
// Try to parse the location as a URL..
//以url形势获取加载的资源.
URL url = new URL(location);
return new UrlResource(url);
}
catch (MalformedURLException ex) {
// No URL -> resolve as resource path.
return getResourceByPath(location);
}
}
}

/**
* Return a Resource handle for the resource at the given path.
* <p>The default implementation supports class path locations. This should
* be appropriate for standalone implementations but can be overridden,
* e.g. for implementations targeted at a Servlet container.
* @param path the path to the resource
* @return the corresponding Resource handle
* @see ClassPathResource
* @see org.springframework.context.support.FileSystemXmlApplicationContext#getResourceByPath
* @see org.springframework.web.context.support.XmlWebApplicationContext#getResourceByPath
*/
protected Resource getResourceByPath(String path) {
return new ClassPathContextResource(path, getClassLoader());
}

/**
* ClassPathResource that explicitly expresses a context-relative path
* through implementing the ContextResource interface.
*/
protected static class ClassPathContextResource extends ClassPathResource implements ContextResource {

public ClassPathContextResource(String path, ClassLoader classLoader) {
super(path, classLoader);
}

@Override
public String getPathWithinContext() {
return getPath();
}

@Override
public Resource createRelative(String relativePath) {
String pathToUse = StringUtils.applyRelativePath(getPath(), relativePath);
return new ClassPathContextResource(pathToUse, getClassLoader());
}
}

该类只是负责默认资源的处理web.xml中的



spring xml的路径，生成Resource类

3、AbstractApplicationContext 类



这个类的接口，DefaultResourceLoader（默认资源加载），

ConfigurableApplicationContext（他实现了ApplicationContext, Lifecycle, Closeable )

就是spring xml文件获取类生命周期，资源销毁，应用上下文的复合接口，此乃核心接口哦；

ApplicationContext：spring的应用上下文实现,

Lifecycle：声明周期接口



Closeable ：销毁web 应用的接口，怎么取消各种资源



、

s

//获取资源正则表达对象

/*
* Copyright 2002-2015 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0 *
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package org.springframework.context.support;

/**
* Abstract implementation of the {@link org.springframework.context.ApplicationContext}
* interface. Doesn't mandate the type of storage used for configuration; simply
* implements common context functionality. Uses the Template Method design pattern,
* requiring concrete subclasses to implement abstract methods.
*
* <p>In contrast to a plain BeanFactory, an ApplicationContext is supposed
* to detect special beans defined in its internal bean factory:
* Therefore, this class automatically registers
* {@link org.springframework.beans.factory.config.BeanFactoryPostProcessor BeanFactoryPostProcessors},
* {@link org.springframework.beans.factory.config.BeanPostProcessor BeanPostProcessors}
* and {@link org.springframework.context.ApplicationListener ApplicationListeners}
* which are defined as beans in the context.
*
* <p>A {@link org.springframework.context.MessageSource} may also be supplied
* as a bean in the context, with the name "messageSource"; otherwise, message
* resolution is delegated to the parent context. Furthermore, a multicaster
* for application events can be supplied as "applicationEventMulticaster" bean
* of type {@link org.springframework.context.event.ApplicationEventMulticaster}
* in the context; otherwise, a default multicaster of type
* {@link org.springframework.context.event.SimpleApplicationEventMulticaster} will be used.
*
* <p>Implements resource loading through extending
* {@link org.springframework.core.io.DefaultResourceLoader}.
* Consequently treats non-URL resource paths as class path resources
* (supporting full class path resource names that include the package path,
* e.g. "mypackage/myresource.dat"), unless the {@link #getResourceByPath}
* method is overwritten in a subclass.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @author Mark Fisher
* @author Stephane Nicoll
* @since January 21, 2001
* @see #refreshBeanFactory
* @see #getBeanFactory
* @see org.springframework.beans.factory.config.BeanFactoryPostProcessor
* @see org.springframework.beans.factory.config.BeanPostProcessor
* @see org.springframework.context.event.ApplicationEventMulticaster
* @see org.springframework.context.ApplicationListener
* @see org.springframework.context.MessageSource

*该类负责整个spring的工厂类的方法是实现，基于模版方法
*/
public abstract class AbstractApplicationContext extends DefaultResourceLoader
implements ConfigurableApplicationContext, DisposableBean {

/**
* Name of the MessageSource bean in the factory.
* If none is supplied, message resolution is delegated to the parent.
* @see MessageSource
*/
public static final String MESSAGE_SOURCE_BEAN_NAME = "messageSource";

/**
* Name of the LifecycleProcessor bean in the factory.
* If none is supplied, a DefaultLifecycleProcessor is used.
* @see org.springframework.context.LifecycleProcessor
* @see org.springframework.context.support.DefaultLifecycleProcessor
*/
public static final String LIFECYCLE_PROCESSOR_BEAN_NAME = "lifecycleProcessor";

/**
* Name of the ApplicationEventMulticaster bean in the factory.
* If none is supplied, a default SimpleApplicationEventMulticaster is used.
* @see org.springframework.context.event.ApplicationEventMulticaster
* @see org.springframework.context.event.SimpleApplicationEventMulticaster
*/
public static final String APPLICATION_EVENT_MULTICASTER_BEAN_NAME = "applicationEventMulticaster";

static {
// Eagerly load the ContextClosedEvent class to avoid weird classloader issues
// on application shutdown in WebLogic 8.1. (Reported by Dustin Woods.)
ContextClosedEvent.class.getName();
}

/** Logger used by this class. Available to subclasses. */
protected final Log logger = LogFactory.getLog(getClass());

/** Unique id for this context, if any */
private String id = ObjectUtils.identityToString(this);

/** Display name */
private String displayName = ObjectUtils.identityToString(this);

/** Parent context */
private ApplicationContext parent;

/** Environment used by this context */
private ConfigurableEnvironment environment;

/** BeanFactoryPostProcessors to apply on refresh */
private final List<BeanFactoryPostProcessor> beanFactoryPostProcessors =
new ArrayList<BeanFactoryPostProcessor>();

/** System time in milliseconds when this context started */
private long startupDate;

/** Flag that indicates whether this context is currently active */
private final AtomicBoolean active = new AtomicBoolean();

/** Flag that indicates whether this context has been closed already */
private final AtomicBoolean closed = new AtomicBoolean();

/** Synchronization monitor for the "refresh" and "destroy" */
private final Object startupShutdownMonitor = new Object();

/** Reference to the JVM shutdown hook, if registered */
private Thread shutdownHook;

/** ResourcePatternResolver used by this context */
private ResourcePatternResolver resourcePatternResolver;

/** LifecycleProcessor for managing the lifecycle of beans within this context */
private LifecycleProcessor lifecycleProcessor;

/** MessageSource we delegate our implementation of this interface to */
private MessageSource messageSource;

/** Helper class used in event publishing */
private ApplicationEventMulticaster applicationEventMulticaster;

/** Statically specified listeners */
private final Set<ApplicationListener<?>> applicationListeners = new LinkedHashSet<ApplicationListener<?>>();

/** ApplicationEvents published early */
private Set<ApplicationEvent> earlyApplicationEvents;

/**
* Create a new AbstractApplicationContext with no parent.
*/
public AbstractApplicationContext() {
this.resourcePatternResolver = getResourcePatternResolver();
}

/**
* Create a new AbstractApplicationContext with the given parent context.
* @param parent the parent context
*/
public AbstractApplicationContext(ApplicationContext parent) {
this();
setParent(parent);
}

//---------------------------------------------------------------------
// Implementation of ApplicationContext interface
//---------------------------------------------------------------------

/**
* Set the unique id of this application context.
* <p>Default is the object id of the context instance, or the name
* of the context bean if the context is itself defined as a bean.
* @param id the unique id of the context
*/
@Override
public void setId(String id) {
this.id = id;
}

@Override
public String getId() {
return this.id;
}

@Override
public String getApplicationName() {
return "";
}

/**
* Set a friendly name for this context.
* Typically done during initialization of concrete context implementations.
* <p>Default is the object id of the context instance.
*/
public void setDisplayName(String displayName) {
Assert.hasLength(displayName, "Display name must not be empty");
this.displayName = displayName;
}

/**
* Return a friendly name for this context.
* @return a display name for this context (never {@code null})
*/
@Override
public String getDisplayName() {
return this.displayName;
}

/**
* Return the parent context, or {@code null} if there is no parent
* (that is, this context is the root of the context hierarchy).
*/
@Override
public ApplicationContext getParent() {
return this.parent;
}

/**
* {@inheritDoc}
* <p>If {@code null}, a new environment will be initialized via
* {@link #createEnvironment()}.
*/
@Override
public ConfigurableEnvironment getEnvironment() {
if (this.environment == null) {
this.environment = createEnvironment();
}
return this.environment;
}

/**
* {@inheritDoc}
* <p>Default value is determined by {@link #createEnvironment()}. Replacing the
* default with this method is one option but configuration through {@link
* #getEnvironment()} should also be considered. In either case, such modifications
* should be performed <em>before</em> {@link #refresh()}.
* @see org.springframework.context.support.AbstractApplicationContext#createEnvironment
*/
@Override
public void setEnvironment(ConfigurableEnvironment environment) {
this.environment = environment;
}

/**
* Return this context's internal bean factory as AutowireCapableBeanFactory,
* if already available.
* @see #getBeanFactory()
*/
@Override
public AutowireCapableBeanFactory getAutowireCapableBeanFactory() throws IllegalStateException {
return getBeanFactory();
}

/**
* Return the timestamp (ms) when this context was first loaded.
*/
@Override
public long getStartupDate() {
return this.startupDate;
}

/**
* Publish the given event to all listeners.
* <p>Note: Listeners get initialized after the MessageSource, to be able
* to access it within listener implementations. Thus, MessageSource
* implementations cannot publish events.
* @param event the event to publish (may be application-specific or a
* standard framework event)
*/
@Override
public void publishEvent(ApplicationEvent event) {
publishEvent(event, null);
}

/**
* Publish the given event to all listeners.
* <p>Note: Listeners get initialized after the MessageSource, to be able
* to access it within listener implementations. Thus, MessageSource
* implementations cannot publish events.
* @param event the event to publish (may be an {@link ApplicationEvent}
* or a payload object to be turned into a {@link PayloadApplicationEvent})
*/
@Override
public void publishEvent(Object event) {
publishEvent(event, null);
}

/**
* Publish the given event to all listeners.
* @param event the event to publish (may be an {@link ApplicationEvent}
* or a payload object to be turned into a {@link PayloadApplicationEvent})
* @param eventType the resolved event type, if known
* @since 4.2
*/
protected void publishEvent(Object event, ResolvableType eventType) {
Assert.notNull(event, "Event must not be null");
if (logger.isTraceEnabled()) {
logger.trace("Publishing event in " + getDisplayName() + ": " + event);
}

// Decorate event as an ApplicationEvent if necessary
ApplicationEvent applicationEvent;
if (event instanceof ApplicationEvent) {
applicationEvent = (ApplicationEvent) event;
}
else {
applicationEvent = new PayloadApplicationEvent<Object>(this, event);
if (eventType == null) {
eventType = ResolvableType.forClassWithGenerics(PayloadApplicationEvent.class, event.getClass());
}
}

// Multicast right now if possible - or lazily once the multicaster is initialized
if (this.earlyApplicationEvents != null) {
this.earlyApplicationEvents.add(applicationEvent);
}
else {
getApplicationEventMulticaster().multicastEvent(applicationEvent, eventType);
}

// Publish event via parent context as well...
if (this.parent != null) {
if (this.parent instanceof AbstractApplicationContext) {
((AbstractApplicationContext) this.parent).publishEvent(event, eventType);
}
else {
this.parent.publishEvent(event);
}
}
}

/**
* Return the internal ApplicationEventMulticaster used by the context.
* @return the internal ApplicationEventMulticaster (never {@code null})
* @throws IllegalStateException if the context has not been initialized yet
*/
ApplicationEventMulticaster getApplicationEventMulticaster() throws IllegalStateException {
if (this.applicationEventMulticaster == null) {
throw new IllegalStateException("ApplicationEventMulticaster not initialized - " +
"call 'refresh' before multicasting events via the context: " + this);
}
return this.applicationEventMulticaster;
}

/**
* Return the internal LifecycleProcessor used by the context.
* @return the internal LifecycleProcessor (never {@code null})
* @throws IllegalStateException if the context has not been initialized yet
*/
LifecycleProcessor getLifecycleProcessor() throws IllegalStateException {
if (this.lifecycleProcessor == null) {
throw new IllegalStateException("LifecycleProcessor not initialized - " +
"call 'refresh' before invoking lifecycle methods via the context: " + this);
}
return this.lifecycleProcessor;
}

/**
* Return the ResourcePatternResolver to use for resolving location patterns
* into Resource instances. Default is a
* {@link org.springframework.core.io.support.PathMatchingResourcePatternResolver},
* supporting Ant-style location patterns.
* <p>Can be overridden in subclasses, for extended resolution strategies,
* for example in a web environment.
* <p><b>Do not call this when needing to resolve a location pattern.</b>
* Call the context's {@code getResources} method instead, which
* will delegate to the ResourcePatternResolver.
* @return the ResourcePatternResolver for this context
* @see #getResources
* @see org.springframework.core.io.support.PathMatchingResourcePatternResolver
*/
protected ResourcePatternResolver getResourcePatternResolver() {
return new PathMatchingResourcePatternResolver(this);
}

//---------------------------------------------------------------------
// Implementation of ConfigurableApplicationContext interface
//---------------------------------------------------------------------

/**
* {@inheritDoc}
* <p>The parent {@linkplain ApplicationContext#getEnvironment() environment} is
* {@linkplain ConfigurableEnvironment#merge(ConfigurableEnvironment) merged} with
* this (child) application context environment if the parent is non-{@code null} and
* its environment is an instance of {@link ConfigurableEnvironment}.
* @see ConfigurableEnvironment#merge(ConfigurableEnvironment)
*/
@Override
public void setParent(ApplicationContext parent) {
this.parent = parent;
if (parent != null) {
Environment parentEnvironment = parent.getEnvironment();
if (parentEnvironment instanceof ConfigurableEnvironment) {
getEnvironment().merge((ConfigurableEnvironment) parentEnvironment);
}
}
}

@Override
public void addBeanFactoryPostProcessor(BeanFactoryPostProcessor beanFactoryPostProcessor) {
this.beanFactoryPostProcessors.add(beanFactoryPostProcessor);
}

/**
* Return the list of BeanFactoryPostProcessors that will get applied
* to the internal BeanFactory.
*/
public List<BeanFactoryPostProcessor> getBeanFactoryPostProcessors() {
return this.beanFactoryPostProcessors;
}

@Override
public void addApplicationListener(ApplicationListener<?> listener) {
if (this.applicationEventMulticaster != null) {
this.applicationEventMulticaster.addApplicationListener(listener);
}
else {
this.applicationListeners.add(listener);
}
}

/**
* Return the list of statically specified ApplicationListeners.
*/
public Collection<ApplicationListener<?>> getApplicationListeners() {
return this.applicationListeners;
}

/**
* Create and return a new {@link StandardEnvironment}.
* <p>Subclasses may override this method in order to supply
* a custom {@link ConfigurableEnvironment} implementation.
* 创建一个标准的环境环境变量
*/
protected ConfigurableEnvironment createEnvironment() {
return new StandardEnvironment();
}
//设置比spring的工程刷新功能，用于初始化用
@Override
public void refresh() throws BeansException, IllegalStateException {
synchronized (this.startupShutdownMonitor) {
// Prepare this context for refreshing.
prepareRefresh();

// Tell the subclass to refresh the internal bean factory.
ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

// Prepare the bean factory for use in this context.
prepareBeanFactory(beanFactory);

try {
// Allows post-processing of the bean factory in context subclasses.
postProcessBeanFactory(beanFactory);

// Invoke factory processors registered as beans in the context.
invokeBeanFactoryPostProcessors(beanFactory);

// Register bean processors that intercept bean creation.
registerBeanPostProcessors(beanFactory);

// Initialize message source for this context.
initMessageSource();

// Initialize event multicaster for this context.
initApplicationEventMulticaster();

// Initialize other special beans in specific context subclasses.
onRefresh();

// Check for listener beans and register them.
registerListeners();

// Instantiate all remaining (non-lazy-init) singletons.
finishBeanFactoryInitialization(beanFactory);

// Last step: publish corresponding event.
finishRefresh();
}

catch (BeansException ex) {
if (logger.isWarnEnabled()) {
logger.warn("Exception encountered during context initialization - " +
"cancelling refresh attempt: " + ex);
}

// Destroy already created singletons to avoid dangling resources.
destroyBeans();

// Reset 'active' flag.
cancelRefresh(ex);

// Propagate exception to caller.
throw ex;
}

finally {
// Reset common introspection caches in Spring's core, since we
// might not ever need metadata for singleton beans anymore...
resetCommonCaches();
}
}
}

/**
* Prepare this context for refreshing, setting its startup date and
* active flag as well as performing any initialization of property sources.
*/
protected void prepareRefresh() {
this.startupDate = System.currentTimeMillis();
this.closed.set(false);
this.active.set(true);

if (logger.isInfoEnabled()) {
logger.info("Refreshing " + this);
}

// Initialize any placeholder property sources in the context environment
initPropertySources();

// Validate that all properties marked as required are resolvable
// see ConfigurablePropertyResolver#setRequiredProperties
getEnvironment().validateRequiredProperties();

// Allow for the collection of early ApplicationEvents,
// to be published once the multicaster is available...
this.earlyApplicationEvents = new LinkedHashSet<ApplicationEvent>();
}

/**
* <p>Replace any stub property sources with actual instances.
* @see org.springframework.core.env.PropertySource.StubPropertySource
* @see org.springframework.web.context.support.WebApplicationContextUtils#initServletPropertySources
*/
protected void initPropertySources() {
// For subclasses: do nothing by default.
}

/**
* Tell the subclass to refresh the internal bean factory.
* @return the fresh BeanFactory instance
* @see #refreshBeanFactory()
* @see #getBeanFactory()
*/
protected ConfigurableListableBeanFactory obtainFreshBeanFactory() {
refreshBeanFactory();
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
if (logger.isDebugEnabled()) {
logger.debug("Bean factory for " + getDisplayName() + ": " + beanFactory);
}
return beanFactory;
}

/**
* Configure the factory's standard context characteristics,
* such as the context's ClassLoader and post-processors.
* @param beanFactory the BeanFactory to configure
*/
protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
// Tell the internal bean factory to use the context's class loader etc.
beanFactory.setBeanClassLoader(getClassLoader());
beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));

// Configure the bean factory with context callbacks.
beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);
beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);
beanFactory.ignoreDependencyInterface(MessageSourceAware.class);
beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);
beanFactory.ignoreDependencyInterface(EnvironmentAware.class);

// BeanFactory interface not registered as resolvable type in a plain factory.
// MessageSource registered (and found for autowiring) as a bean.
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());
}
}

/**
* Modify the application context's internal bean factory after its standard
* initialization. All bean definitions will have been loaded, but no beans
* will have been instantiated yet. This allows for registering special
* BeanPostProcessors etc in certain ApplicationContext implementations.
* @param beanFactory the bean factory used by the application context
*/
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
}

/**
* Instantiate and invoke all registered BeanFactoryPostProcessor beans,
* respecting explicit order if given.
* <p>Must be called before singleton instantiation.
*/
protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());
}

/**
* Instantiate and invoke all registered BeanPostProcessor beans,
* respecting explicit order if given.
* <p>Must be called before any instantiation of application beans.
*/
protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) {
PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);
}

/**
* Initialize the MessageSource.
* Use parent's if none defined in this context.
*/
protected void initMessageSource() {
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
if (beanFactory.containsLocalBean(MESSAGE_SOURCE_BEAN_NAME)) {
this.messageSource = beanFactory.getBean(MESSAGE_SOURCE_BEAN_NAME, MessageSource.class);
// Make MessageSource aware of parent MessageSource.
if (this.parent != null && this.messageSource instanceof HierarchicalMessageSource) {
HierarchicalMessageSource hms = (HierarchicalMessageSource) this.messageSource;
if (hms.getParentMessageSource() == null) {
// Only set parent context as parent MessageSource if no parent MessageSource
// registered already.
hms.setParentMessageSource(getInternalParentMessageSource());
}
}
if (logger.isDebugEnabled()) {
logger.debug("Using MessageSource [" + this.messageSource + "]");
}
}
else {
// Use empty MessageSource to be able to accept getMessage calls.
DelegatingMessageSource dms = new DelegatingMessageSource();
dms.setParentMessageSource(getInternalParentMessageSource());
this.messageSource = dms;
beanFactory.registerSingleton(MESSAGE_SOURCE_BEAN_NAME, this.messageSource);
if (logger.isDebugEnabled()) {
logger.debug("Unable to locate MessageSource with name '" + MESSAGE_SOURCE_BEAN_NAME +
"': using default [" + this.messageSource + "]");
}
}
}

/**
* Initialize the ApplicationEventMulticaster.
* Uses SimpleApplicationEventMulticaster if none defined in the context.
* @see org.springframework.context.event.SimpleApplicationEventMulticaster
*/
protected void initApplicationEventMulticaster() {
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) {
this.applicationEventMulticaster =
beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class);
if (logger.isDebugEnabled()) {
logger.debug("Using ApplicationEventMulticaster [" + this.applicationEventMulticaster + "]");
}
}
else {
this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory);
beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster);
if (logger.isDebugEnabled()) {
logger.debug("Unable to locate ApplicationEventMulticaster with name '" +
APPLICATION_EVENT_MULTICASTER_BEAN_NAME +
"': using default [" + this.applicationEventMulticaster + "]");
}
}
}

/**
* Initialize the LifecycleProcessor.
* Uses DefaultLifecycleProcessor if none defined in the context.
* @see org.springframework.context.support.DefaultLifecycleProcessor
*/
protected void initLifecycleProcessor() {
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
if (beanFactory.containsLocalBean(LIFECYCLE_PROCESSOR_BEAN_NAME)) {
this.lifecycleProcessor =
beanFactory.getBean(LIFECYCLE_PROCESSOR_BEAN_NAME, LifecycleProcessor.class);
if (logger.isDebugEnabled()) {
logger.debug("Using LifecycleProcessor [" + this.lifecycleProcessor + "]");
}
}
else {
DefaultLifecycleProcessor defaultProcessor = new DefaultLifecycleProcessor();
defaultProcessor.setBeanFactory(beanFactory);
this.lifecycleProcessor = defaultProcessor;
beanFactory.registerSingleton(LIFECYCLE_PROCESSOR_BEAN_NAME, this.lifecycleProcessor);
if (logger.isDebugEnabled()) {
logger.debug("Unable to locate LifecycleProcessor with name '" +
LIFECYCLE_PROCESSOR_BEAN_NAME +
"': using default [" + this.lifecycleProcessor + "]");
}
}
}

/**
* Template method which can be overridden to add context-specific refresh work.
* Called on initialization of special beans, before instantiation of singletons.
* <p>This implementation is empty.
* @throws BeansException in case of errors
* @see #refresh()
*/
protected void onRefresh() throws BeansException {
// For subclasses: do nothing by default.
}

/**
* Add beans that implement ApplicationListener as listeners.
* Doesn't affect other listeners, which can be added without being beans.
*/
protected void registerListeners() {
// Register statically specified listeners first.
for (ApplicationListener<?> listener : getApplicationListeners()) {
getApplicationEventMulticaster().addApplicationListener(listener);
}

// Do not initialize FactoryBeans here: We need to leave all regular beans
// uninitialized to let post-processors apply to them!
String[] listenerBeanNames = getBeanNamesForType(ApplicationListener.class, true, false);
for (String listenerBeanName : listenerBeanNames) {
getApplicationEventMulticaster().addApplicationListenerBean(listenerBeanName);
}

// Publish early application events now that we finally have a multicaster...
Set<ApplicationEvent> earlyEventsToProcess = this.earlyApplicationEvents;
this.earlyApplicationEvents = null;
if (earlyEventsToProcess != null) {
for (ApplicationEvent earlyEvent : earlyEventsToProcess) {
getApplicationEventMulticaster().multicastEvent(earlyEvent);
}
}
}

/**
* Finish the initialization of this context's bean factory,
* initializing all remaining singleton beans.
*/
protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {
// Initialize conversion service for this context.
if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) &&
beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) {
beanFactory.setConversionService(
beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class));
}

// Initialize LoadTimeWeaverAware beans early to allow for registering their transformers early.
String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);
for (String weaverAwareName : weaverAwareNames) {
getBean(weaverAwareName);
}

// Stop using the temporary ClassLoader for type matching.
beanFactory.setTempClassLoader(null);

// Allow for caching all bean definition metadata, not expecting further changes.
beanFactory.freezeConfiguration();

// Instantiate all remaining (non-lazy-init) singletons.
beanFactory.preInstantiateSingletons();
}

/**
* Finish the refresh of this context, invoking the LifecycleProcessor's
* onRefresh() method and publishing the
* {@link org.springframework.context.event.ContextRefreshedEvent}.
*/
protected void finishRefresh() {
// Initialize lifecycle processor for this context.
initLifecycleProcessor();

// Propagate refresh to lifecycle processor first.
getLifecycleProcessor().onRefresh();

// Publish the final event.
publishEvent(new ContextRefreshedEvent(this));

// Participate in LiveBeansView MBean, if active.
LiveBeansView.registerApplicationContext(this);
}

/**
* Cancel this context's refresh attempt, resetting the {@code active} flag
* after an exception got thrown.
* @param ex the exception that led to the cancellation
*/
protected void cancelRefresh(BeansException ex) {
this.active.set(false);
}

/**
* Reset Spring's common core caches, in particular the {@link ReflectionUtils},
* {@link ResolvableType} and {@link CachedIntrospectionResults} caches.
* @since 4.2
* @see ReflectionUtils#clearCache()
* @see ResolvableType#clearCache()
* @see CachedIntrospectionResults#clearClassLoader(ClassLoader)
*/
protected void resetCommonCaches() {
ReflectionUtils.clearCache();
ResolvableType.clearCache();
CachedIntrospectionResults.clearClassLoader(getClassLoader());
}

/**
* Register a shutdown hook with the JVM runtime, closing this context
* on JVM shutdown unless it has already been closed at that time.
* <p>Delegates to {@code doClose()} for the actual closing procedure.
* @see Runtime#addShutdownHook
* @see #close()
* @see #doClose()
*/
@Override
public void registerShutdownHook() {
if (this.shutdownHook == null) {
// No shutdown hook registered yet.
this.shutdownHook = new Thread() {
@Override
public void run() {
synchronized (startupShutdownMonitor) {
doClose();
}
}
};
Runtime.getRuntime().addShutdownHook(this.shutdownHook);
}
}

/**
* DisposableBean callback for destruction of this instance.
* Only called when the ApplicationContext itself is running
* as a bean in another BeanFactory or ApplicationContext,
* which is rather unusual.
* <p>The {@code close} method is the native way to
* shut down an ApplicationContext.
* @see #close()
* @see org.springframework.beans.factory.access.SingletonBeanFactoryLocator
*/
@Override
public void destroy() {
close();
}

/**
* Close this application context, destroying all beans in its bean factory.
* <p>Delegates to {@code doClose()} for the actual closing procedure.
* Also removes a JVM shutdown hook, if registered, as it's not needed anymore.
* @see #doClose()
* @see #registerShutdownHook()
*/
@Override
public void close() {
synchronized (this.startupShutdownMonitor) {
doClose();
// If we registered a JVM shutdown hook, we don't need it anymore now:
// We've already explicitly closed the context.
if (this.shutdownHook != null) {
try {
Runtime.getRuntime().removeShutdownHook(this.shutdownHook);
}
catch (IllegalStateException ex) {
// ignore - VM is already shutting down
}
}
}
}

/**
* Actually performs context closing: publishes a ContextClosedEvent and
* destroys the singletons in the bean factory of this application context.
* <p>Called by both {@code close()} and a JVM shutdown hook, if any.
* @see org.springframework.context.event.ContextClosedEvent
* @see #destroyBeans()
* @see #close()
* @see #registerShutdownHook()
*/
protected void doClose() {
if (this.active.get() && this.closed.compareAndSet(false, true)) {
if (logger.isInfoEnabled()) {
logger.info("Closing " + this);
}

LiveBeansView.unregisterApplicationContext(this);

try {
// Publish shutdown event.
publishEvent(new ContextClosedEvent(this));
}
catch (Throwable ex) {
logger.warn("Exception thrown from ApplicationListener handling ContextClosedEvent", ex);
}

// Stop all Lifecycle beans, to avoid delays during individual destruction.
try {
getLifecycleProcessor().onClose();
}
catch (Throwable ex) {
logger.warn("Exception thrown from LifecycleProcessor on context close", ex);
}

// Destroy all cached singletons in the context's BeanFactory.
destroyBeans();

// Close the state of this context itself.
closeBeanFactory();

// Let subclasses do some final clean-up if they wish...
onClose();

this.active.set(false);
}
}

/**
* Template method for destroying all beans that this context manages.
* The default implementation destroy all cached singletons in this context,
* invoking {@code DisposableBean.destroy()} and/or the specified
* "destroy-method".
* <p>Can be overridden to add context-specific bean destruction steps
* right before or right after standard singleton destruction,
* while the context's BeanFactory is still active.
* @see #getBeanFactory()
* @see org.springframework.beans.factory.config.ConfigurableBeanFactory#destroySingletons()
*/
protected void destroyBeans() {
getBeanFactory().destroySingletons();
}

/**
* Template method which can be overridden to add context-specific shutdown work.
* The default implementation is empty.
* <p>Called at the end of {@link #doClose}'s shutdown procedure, after
* this context's BeanFactory has been closed. If custom shutdown logic
* needs to execute while the BeanFactory is still active, override
* the {@link #destroyBeans()} method instead.
*/
protected void onClose() {
// For subclasses: do nothing by default.
}

@Override
public boolean isActive() {
return this.active.get();
}

/**
* Assert that this context's BeanFactory is currently active,
* throwing an {@link IllegalStateException} if it isn't.
* <p>Invoked by all {@link BeanFactory} delegation methods that depend
* on an active context, i.e. in particular all bean accessor methods.
* <p>The default implementation checks the {@link #isActive() 'active'} status
* of this context overall. May be overridden for more specific checks, or for a
* no-op if {@link #getBeanFactory()} itself throws an exception in such a case.
*/
protected void assertBeanFactoryActive() {
if (!this.active.get()) {
if (this.closed.get()) {
throw new IllegalStateException(getDisplayName() + " has been closed already");
}
else {
throw new IllegalStateException(getDisplayName() + " has not been refreshed yet");
}
}
}

//---------------------------------------------------------------------
// Implementation of BeanFactory interface
//---------------------------------------------------------------------

@Override
public Object getBean(String name) throws BeansException {
assertBeanFactoryActive();
return getBeanFactory().getBean(name);
}

@Override
public <T> T getBean(String name, Class<T> requiredType) throws BeansException {
assertBeanFactoryActive();
return getBeanFactory().getBean(name, requiredType);
}

@Override
public <T> T getBean(Class<T> requiredType) throws BeansException {
assertBeanFactoryActive();
return getBeanFactory().getBean(requiredType);
}

@Override
public Object getBean(String name, Object... args) throws BeansException {
assertBeanFactoryActive();
return getBeanFactory().getBean(name, args);
}

@Override
public <T> T getBean(Class<T> requiredType, Object... args) throws BeansException {
assertBeanFactoryActive();
return getBeanFactory().getBean(requiredType, args);
}

@Override
public boolean containsBean(String name) {
return getBeanFactory().containsBean(name);
}

@Override
public boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
assertBeanFactoryActive();
return getBeanFactory().isSingleton(name);
}

@Override
public boolean isPrototype(String name) throws NoSuchBeanDefinitionException {
assertBeanFactoryActive();
return getBeanFactory().isPrototype(name);
}

@Override
public boolean isTypeMatch(String name, ResolvableType typeToMatch) throws NoSuchBeanDefinitionException {
assertBeanFactoryActive();
return getBeanFactory().isTypeMatch(name, typeToMatch);
}

@Override
public boolean isTypeMatch(String name, Class<?> typeToMatch) throws NoSuchBeanDefinitionException {
assertBeanFactoryActive();
return getBeanFactory().isTypeMatch(name, typeToMatch);
}

@Override
public Class<?> getType(String name) throws NoSuchBeanDefinitionException {
assertBeanFactoryActive();
return getBeanFactory().getType(name);
}

@Override
public String[] getAliases(String name) {
return getBeanFactory().getAliases(name);
}

//---------------------------------------------------------------------
// Implementation of ListableBeanFactory interface
//---------------------------------------------------------------------

@Override
public boolean containsBeanDefinition(String beanName) {
return getBeanFactory().containsBeanDefinition(beanName);
}

@Override
public int getBeanDefinitionCount() {
return getBeanFactory().getBeanDefinitionCount();
}

@Override
public String[] getBeanDefinitionNames() {
return getBeanFactory().getBeanDefinitionNames();
}

@Override
public String[] getBeanNamesForType(ResolvableType type) {
assertBeanFactoryActive();
return getBeanFactory().getBeanNamesForType(type);
}

@Override
public String[] getBeanNamesForType(Class<?> type) {
assertBeanFactoryActive();
return getBeanFactory().getBeanNamesForType(type);
}

@Override
public String[] getBeanNamesForType(Class<?> type, boolean includeNonSingletons, boolean allowEagerInit) {
assertBeanFactoryActive();
return getBeanFactory().getBeanNamesForType(type, includeNonSingletons, allowEagerInit);
}

@Override
public <T> Map<String, T> getBeansOfType(Class<T> type) throws BeansException {
assertBeanFactoryActive();
return getBeanFactory().getBeansOfType(type);
}

@Override
public <T> Map<String, T> getBeansOfType(Class<T> type, boolean includeNonSingletons, boolean allowEagerInit)
throws BeansException {

assertBeanFactoryActive();
return getBeanFactory().getBeansOfType(type, includeNonSingletons, allowEagerInit);
}

@Override
public String[] getBeanNamesForAnnotation(Class<? extends Annotation> annotationType) {
assertBeanFactoryActive();
return getBeanFactory().getBeanNamesForAnnotation(annotationType);
}

@Override
public Map<String, Object> getBeansWithAnnotation(Class<? extends Annotation> annotationType)
throws BeansException {

assertBeanFactoryActive();
return getBeanFactory().getBeansWithAnnotation(annotationType);
}

@Override
public <A extends Annotation> A findAnnotationOnBean(String beanName, Class<A> annotationType)
throws NoSuchBeanDefinitionException{

assertBeanFactoryActive();
return getBeanFactory().findAnnotationOnBean(beanName, annotationType);
}

//---------------------------------------------------------------------
// Implementation of HierarchicalBeanFactory interface
//---------------------------------------------------------------------

@Override
public BeanFactory getParentBeanFactory() {
return getParent();
}

@Override
public boolean containsLocalBean(String name) {
return getBeanFactory().containsLocalBean(name);
}

/**
* Return the internal bean factory of the parent context if it implements
* ConfigurableApplicationContext; else, return the parent context itself.
* @see org.springframework.context.ConfigurableApplicationContext#getBeanFactory
*/
protected BeanFactory getInternalParentBeanFactory() {
return (getParent() instanceof ConfigurableApplicationContext) ?
((ConfigurableApplicationContext) getParent()).getBeanFactory() : getParent();
}

//---------------------------------------------------------------------
// Implementation of MessageSource interface
//---------------------------------------------------------------------

@Override
public String getMessage(String code, Object args[], String defaultMessage, Locale locale) {
return getMessageSource().getMessage(code, args, defaultMessage, locale);
}

@Override
public String getMessage(String code, Object args[], Locale locale) throws NoSuchMessageException {
return getMessageSource().getMessage(code, args, locale);
}

@Override
public String getMessage(MessageSourceResolvable resolvable, Locale locale) throws NoSuchMessageException {
return getMessageSource().getMessage(resolvable, locale);
}

/**
* Return the internal MessageSource used by the context.
* @return the internal MessageSource (never {@code null})
* @throws IllegalStateException if the context has not been initialized yet
*/
private MessageSource getMessageSource() throws IllegalStateException {
if (this.messageSource == null) {
throw new IllegalStateException("MessageSource not initialized - " +
"call 'refresh' before accessing messages via the context: " + this);
}
return this.messageSource;
}

/**
* Return the internal message source of the parent context if it is an
* AbstractApplicationContext too; else, return the parent context itself.
*/
protected MessageSource getInternalParentMessageSource() {
return (getParent() instanceof AbstractApplicationContext) ?
((AbstractApplicationContext) getParent()).messageSource : getParent();
}

//---------------------------------------------------------------------
// Implementation of ResourcePatternResolver interface
//---------------------------------------------------------------------

@Override
public Resource[] getResources(String locationPattern) throws IOException {
return this.resourcePatternResolver.getResources(locationPattern);
}

//---------------------------------------------------------------------
// Implementation of Lifecycle interface
//---------------------------------------------------------------------

@Override
public void start() {
getLifecycleProcessor().start();
publishEvent(new ContextStartedEvent(this));
}

@Override
public void stop() {
getLifecycleProcessor().stop();
publishEvent(new ContextStoppedEvent(this));
}

@Override
public boolean isRunning() {
return (this.lifecycleProcessor != null && this.lifecycleProcessor.isRunning());
}

//---------------------------------------------------------------------
// Abstract methods that must be implemented by subclasses
//---------------------------------------------------------------------

/**
* Subclasses must implement this method to perform the actual configuration load.
* The method is invoked by {@link #refresh()} before any other initialization work.
* <p>A subclass will either create a new bean factory and hold a reference to it,
* or return a single BeanFactory instance that it holds. In the latter case, it will
* usually throw an IllegalStateException if refreshing the context more than once.
* @throws BeansException if initialization of the bean factory failed
* @throws IllegalStateException if already initialized and multiple refresh
* attempts are not supported
*/
protected abstract void refreshBeanFactory() throws BeansException, IllegalStateException;

/**
* Subclasses must implement this method to release their internal bean factory.
* This method gets invoked by {@link #close()} after all other shutdown work.
* <p>Should never throw an exception but rather log shutdown failures.
*/
protected abstract void closeBeanFactory();

/**
* Subclasses must return their internal bean factory here. They should implement the
* lookup efficiently, so that it can be called repeatedly without a performance penalty.
* <p>Note: Subclasses should check whether the context is still active before
* returning the internal bean factory. The internal factory should generally be
* considered unavailable once the context has been closed.
* @return this application context's internal bean factory (never {@code null})
* @throws IllegalStateException if the context does not hold an internal bean factory yet
* (usually if {@link #refresh()} has never been called) or if the context has been
* closed already
* @see #refreshBeanFactory()
* @see #closeBeanFactory()
*/
@Override
public abstract ConfigurableListableBeanFactory getBeanFactory() throws IllegalStateException;

/**
* Return information about this context.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder(getDisplayName());
sb.append(": startup date [").append(new Date(getStartupDate()));
sb.append("]; ");
ApplicationContext parent = getParent();
if (parent == null) {
sb.append("root of context hierarchy");
}
else {
sb.append("parent: ").append(parent.getDisplayName());
}
return sb.toString();
}

}