spring mvc Displatch Servlet詳細解の一つ---処理要求の詳細解析(続)
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上記では、配信プロセスには以下のステップがあることを知っている.
配布の過程は以下の通りです.
1.multiiprt requestを設置しているかどうかを判断し、設置するとmultiipad requestに変換し、ない場合は次のステップを継続します.
2.現在のrequestによってハング・ドルを取得します.
3.現在のrequestによって、HandlerAdapterを取得します.
4.httpリクエストヘッドをサポートするなら、処理する. last-modified header要求ヘッド.
5.登録済みのintercepterのpreHandle方法を適用する
6. Handler Adapter処理要求.
7.標準表示を設定します.
8. 登録済みのinterceptorのpostHandle方法を適用します.
9.異常または表示レンダリングを処理します.
この節については、手順2のステップ3を詳しく見てみます.どのようにrequestからhanderとhanderAdapterを取得しますか?
現在のrequestによってhandler Execution Charinを取得します.
配布の過程は以下の通りです.
1.multiiprt requestを設置しているかどうかを判断し、設置するとmultiipad requestに変換し、ない場合は次のステップを継続します.
2.現在のrequestによってハング・ドルを取得します.
3.現在のrequestによって、HandlerAdapterを取得します.
4.httpリクエストヘッドをサポートするなら、処理する. last-modified header要求ヘッド.
5.登録済みのintercepterのpreHandle方法を適用する
6. Handler Adapter処理要求.
7.標準表示を設定します.
8. 登録済みのinterceptorのpostHandle方法を適用します.
9.異常または表示レンダリングを処理します.
この節については、手順2のステップ3を詳しく見てみます.どのようにrequestからhanderとhanderAdapterを取得しますか?
現在のrequestによってhandler Execution Charinを取得します.
/**
* Return the HandlerExecutionChain for this request.
* <p>Tries all handler mappings in order.
* @param request current HTTP request
* @return the HandlerExecutionChain, or {@code null} if no handler could be found
*/
protected HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
for (HandlerMapping hm : this.handlerMappings) {
if (logger.isTraceEnabled()) {
logger.trace(
"Testing handler map [" + hm + "] in DispatcherServlet with name '" + getServletName() + "'");
}
HandlerExecutionChain handler = hm.getHandler(request);
if (handler != null) {
return handler;
}
}
return null;
} // Find all HandlerMappings in the ApplicationContext, including ancestor contexts.
Map<String, HandlerMapping> matchingBeans =
BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerMapping.class, true, false);
if (!matchingBeans.isEmpty()) {
this.handlerMappings = new ArrayList<HandlerMapping>(matchingBeans.values());
// We keep HandlerMappings in sorted order.
OrderComparator.sort(this.handlerMappings);
} /**
* Look up a handler for the given request, falling back to the default
* handler if no specific one is found.
* @param request current HTTP request
* @return the corresponding handler instance, or the default handler
* @see #getHandlerInternal
*/
@Override
public final HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
Object handler = getHandlerInternal(request);
if (handler == null) {
handler = getDefaultHandler();
}
if (handler == null) {
return null;
}
// Bean name or resolved handler?
if (handler instanceof String) {
String handlerName = (String) handler;
handler = getApplicationContext().getBean(handlerName);
}
return getHandlerExecutionChain(handler, request);
}Object handler = getHandlerInternal(request); AbstractHandlerMapping.java ， ：
AbstractHandlerMethodMapping.java /**
* Look up a handler method for the given request.
*/
@Override
protected HandlerMethod getHandlerInternal(HttpServletRequest request) throws Exception {
String lookupPath = getUrlPathHelper().getLookupPathForRequest(request);
if (logger.isDebugEnabled()) {
logger.debug("Looking up handler method for path " + lookupPath);
}
HandlerMethod handlerMethod = lookupHandlerMethod(lookupPath, request);
if (logger.isDebugEnabled()) {
if (handlerMethod != null) {
logger.debug("Returning handler method [" + handlerMethod + "]");
}
else {
logger.debug("Did not find handler method for [" + lookupPath + "]");
}
}
return (handlerMethod != null ? handlerMethod.createWithResolvedBean() : null);
} /**
* Look up a handler for the URL path of the given request.
* @param request current HTTP request
* @return the handler instance, or {@code null} if none found
*/
@Override
protected Object getHandlerInternal(HttpServletRequest request) throws Exception {
String lookupPath = getUrlPathHelper().getLookupPathForRequest(request);
Object handler = lookupHandler(lookupPath, request);
if (handler == null) {
// We need to care for the default handler directly, since we need to
// expose the PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE for it as well.
Object rawHandler = null;
if ("/".equals(lookupPath)) {
rawHandler = getRootHandler();
}
if (rawHandler == null) {
rawHandler = getDefaultHandler();
}
if (rawHandler != null) {
// Bean name or resolved handler?
if (rawHandler instanceof String) {
String handlerName = (String) rawHandler;
rawHandler = getApplicationContext().getBean(handlerName);
}
validateHandler(rawHandler, request);
handler = buildPathExposingHandler(rawHandler, lookupPath, lookupPath, null);
}
}
if (handler != null && logger.isDebugEnabled()) {
logger.debug("Mapping [" + lookupPath + "] to " + handler);
}
else if (handler == null && logger.isTraceEnabled()) {
logger.trace("No handler mapping found for [" + lookupPath + "]");
}
return handler;
} /**
* Build a {@link HandlerExecutionChain} for the given handler, including
* applicable interceptors.
* <p>The default implementation builds a standard {@link HandlerExecutionChain}
* with the given handler, the handler mapping's common interceptors, and any
* {@link MappedInterceptor}s matching to the current request URL. Subclasses
* may override this in order to extend/rearrange the list of interceptors.
* <p><b>NOTE:</b> The passed-in handler object may be a raw handler or a
* pre-built {@link HandlerExecutionChain}. This method should handle those
* two cases explicitly, either building a new {@link HandlerExecutionChain}
* or extending the existing chain.
* <p>For simply adding an interceptor in a custom subclass, consider calling
* {@code super.getHandlerExecutionChain(handler, request)} and invoking
* {@link HandlerExecutionChain#addInterceptor} on the returned chain object.
* @param handler the resolved handler instance (never {@code null})
* @param request current HTTP request
* @return the HandlerExecutionChain (never {@code null})
* @see #getAdaptedInterceptors()
*/
protected HandlerExecutionChain getHandlerExecutionChain(Object handler, HttpServletRequest request) {
HandlerExecutionChain chain = (handler instanceof HandlerExecutionChain ?
(HandlerExecutionChain) handler : new HandlerExecutionChain(handler));
chain.addInterceptors(getAdaptedInterceptors());
String lookupPath = this.urlPathHelper.getLookupPathForRequest(request);
for (MappedInterceptor mappedInterceptor : this.mappedInterceptors) {
if (mappedInterceptor.matches(lookupPath, this.pathMatcher)) {
chain.addInterceptor(mappedInterceptor.getInterceptor());
}
}
return chain;
}