// Acquire the filter mappings for this Context //4.!!!这里挺关键的，拿到了wrapper.getParent(), 这个context就是 StandardContext context = (StandardContext) wrapper.getParent(); FilterMap filterMaps[] = context.findFilterMaps();
// If there are no filter mappings, we are done if ((filterMaps == null) || (filterMaps.length == 0)) return (filterChain);
// Acquire the information we will need to match filter mappings DispatcherType dispatcher =//5.="REQUEST" (DispatcherType) request.getAttribute(Globals.DISPATCHER_TYPE_ATTR);
//7.这里就是匹配一下request，把相关的放进filterChain里，这次request是全部都放进去了 // Add the relevant path-mapped filters to this filter chain for (int i = 0; i < filterMaps.length; i++) { if (!matchDispatcher(filterMaps[i] ,dispatcher)) { continue; } if (!matchFiltersURL(filterMaps[i], requestPath)) continue; ApplicationFilterConfig filterConfig = (ApplicationFilterConfig) context.findFilterConfig(filterMaps[i].getFilterName()); if (filterConfig == null) { // FIXME - log configuration problem continue; } filterChain.addFilter(filterConfig); } //8.这里filterChain已经有7个了 // Add filters that match on servlet name second for (int i = 0; i < filterMaps.length; i++) { if (!matchDispatcher(filterMaps[i] ,dispatcher)) { continue; } //9.这里servletName=dispatcherServlet if (!matchFiltersServlet(filterMaps[i], servletName)) continue; ApplicationFilterConfig filterConfig = (ApplicationFilterConfig) context.findFilterConfig(filterMaps[i].getFilterName()); if (filterConfig == null) { // FIXME - log configuration problem continue; } //10.这里没走到 filterChain.addFilter(filterConfig); }
// Return the completed filter chain return filterChain; }
//2. 支持urlPath pattern 匹配 // Pattern match? List<String> matchingPatterns = new ArrayList<>(); for (String registeredPattern : this.handlerMap.keySet()) { if (getPathMatcher().match(registeredPattern, urlPath)) { matchingPatterns.add(registeredPattern); } elseif (useTrailingSlashMatch()) { if (!registeredPattern.endsWith("/") && getPathMatcher().match(registeredPattern + "/", urlPath)) { matchingPatterns.add(registeredPattern +"/"); } } }
String bestMatch = null; Comparator<String> patternComparator = getPathMatcher().getPatternComparator(urlPath); if (!matchingPatterns.isEmpty()) { matchingPatterns.sort(patternComparator); if (logger.isDebugEnabled()) { logger.debug("Matching patterns for request [" + urlPath + "] are " + matchingPatterns); } //3.如果有一堆匹配，只取第一个 bestMatch = matchingPatterns.get(0); } if (bestMatch != null) { handler = this.handlerMap.get(bestMatch); if (handler == null) { //4.这里保证path结尾有没有"/"都一样 if (bestMatch.endsWith("/")) { handler = this.handlerMap.get(bestMatch.substring(0, bestMatch.length() - 1)); } if (handler == null) { thrownew IllegalStateException( "Could not find handler for best pattern match [" + bestMatch + "]"); } } // Bean name or resolved handler? if (handler instanceof String) { String handlerName = (String) handler; handler = obtainApplicationContext().getBean(handlerName); } validateHandler(handler, request); String pathWithinMapping = getPathMatcher().extractPathWithinPattern(bestMatch, urlPath);
// There might be multiple 'best patterns', let's make sure we have the correct URI template variables // for all of them Map<String, String> uriTemplateVariables = new LinkedHashMap<>(); for (String matchingPattern : matchingPatterns) { if (patternComparator.compare(bestMatch, matchingPattern) == 0) { Map<String, String> vars = getPathMatcher().extractUriTemplateVariables(matchingPattern, urlPath); Map<String, String> decodedVars = getUrlPathHelper().decodePathVariables(request, vars); uriTemplateVariables.putAll(decodedVars); } } if (logger.isDebugEnabled()) { logger.debug("URI Template variables for request [" + urlPath + "] are " + uriTemplateVariables); } return buildPathExposingHandler(handler, bestMatch, pathWithinMapping, uriTemplateVariables); }
