spring起動過程のソース追跡(下)--spring Debug
17713 ワード
webアプリケーションの入り口ではContect Loader Listenerですが、どうやって起動プロセスを完了しますか?
まず、
1.context Loader Listener.java
まず、
public class ContextLoaderListenerextends Object implements ServletContextListener
//Bootstrap listener to start up Spring's root WebApplicationContext. Simply delegates to ContextLoader.
//This listener should be registered after Log4jConfigListener in web.xml, if the latter is used.
public abstract interface javax.servlet.ServletContextListener extends java.util.EventListener1.context Loader Listener.java
1 public void contextInitialized(ServletContextEvent event) {
2 this.contextLoader = createContextLoader();
3 this.contextLoader.initWebApplicationContext(event.getServletContext());
4 } 1 /**
2 * Initialize Spring's web application context for the given servlet context,
3 * according to the "{@link #CONTEXT_CLASS_PARAM contextClass}" and
4 * "{@link #CONFIG_LOCATION_PARAM contextConfigLocation}" context-params.
5 * @param servletContext current servlet context
6 * @return the new WebApplicationContext
7 * @throws IllegalStateException if there is already a root application context present
8 * @throws BeansException if the context failed to initialize
9 * @see #CONTEXT_CLASS_PARAM
10 * @see #CONFIG_LOCATION_PARAM
11 */
12 public WebApplicationContext initWebApplicationContext(ServletContext servletContext)
13 throws IllegalStateException, BeansException {
14
15 if (servletContext.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE) != null) {
16 throw new IllegalStateException(
17 "Cannot initialize context because there is already a root application context present - " +
18 "check whether you have multiple ContextLoader* definitions in your web.xml!");
19 }
20
21 servletContext.log("Initializing Spring root WebApplicationContext");
22 if (logger.isInfoEnabled()) {
23 logger.info("Root WebApplicationContext: initialization started");
24 }
25 long startTime = System.currentTimeMillis();
26
27 try {
28 // Determine parent for root web application context, if any.
29 ApplicationContext parent = loadParentContext(servletContext);
30
31 // Store context in local instance variable, to guarantee that
32 // it is available on ServletContext shutdown.
33 this.context = createWebApplicationContext(servletContext, parent);
34 servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, this.context);
35 currentContextPerThread.put(Thread.currentThread().getContextClassLoader(), this.context);
36
37 if (logger.isDebugEnabled()) {
38 logger.debug("Published root WebApplicationContext as ServletContext attribute with name [" +
39 WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE + "]");
40 }
41 if (logger.isInfoEnabled()) {
42 long elapsedTime = System.currentTimeMillis() - startTime;
43 logger.info("Root WebApplicationContext: initialization completed in " + elapsedTime + " ms");
44 }
45
46 return this.context;
47 }
48 catch (RuntimeException ex) {
49 logger.error("Context initialization failed", ex);
50 servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, ex);
51 throw ex;
52 }
53 catch (Error err) {
54 logger.error("Context initialization failed", err);
55 servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, err);
56 throw err;
57 }
58 } 1 protected WebApplicationContext createWebApplicationContext(
2 ServletContext servletContext, ApplicationContext parent) throws BeansException {
3
4 Class contextClass = determineContextClass(servletContext);
5 if (!ConfigurableWebApplicationContext.class.isAssignableFrom(contextClass)) {
6 throw new ApplicationContextException("Custom context class [" + contextClass.getName() +
7 "] is not of type [" + ConfigurableWebApplicationContext.class.getName() + "]");
8 }
9
10 ConfigurableWebApplicationContext wac =
11 (ConfigurableWebApplicationContext) BeanUtils.instantiateClass(contextClass);
12 wac.setParent(parent);
13 wac.setServletContext(servletContext);
14 wac.setConfigLocation(servletContext.getInitParameter(CONFIG_LOCATION_PARAM));
15 customizeContext(servletContext, wac);
16 wac.refresh();
17
18 return wac;
19 } 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) {
// Destroy already created singletons to avoid dangling resources.
beanFactory.destroySingletons();
// Reset 'active' flag.
cancelRefresh(ex);
// Propagate exception to caller.
throw ex;
}
}
}