spring mvc controller处理

@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);
    }

上面是dispatch里调用的,关键类

org.springframework.web.servlet.handler.AbstractHandlerMethodMapping 中

 

 

@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);
    }

 

    protected HandlerMethod lookupHandlerMethod(String lookupPath, HttpServletRequest request) throws Exception {
        List<Match> matches = new ArrayList<Match>();
        List<T> directPathMatches = this.urlMap.get(lookupPath);
        if (directPathMatches != null) {
            addMatchingMappings(directPathMatches, matches, request);
        }
        if (matches.isEmpty()) {
            // No choice but to go through all mappings...
            addMatchingMappings(this.handlerMethods.keySet(), matches, request);
        }

        if (!matches.isEmpty()) {
            Comparator<Match> comparator = new MatchComparator(getMappingComparator(request));
            Collections.sort(matches, comparator);
            if (logger.isTraceEnabled()) {
                logger.trace("Found " + matches.size() + " matching mapping(s) for [" + lookupPath + "] : " + matches);
            }
            Match bestMatch = matches.get(0);
            if (matches.size() > 1) {
                Match secondBestMatch = matches.get(1);
                if (comparator.compare(bestMatch, secondBestMatch) == 0) {
                    Method m1 = bestMatch.handlerMethod.getMethod();
                    Method m2 = secondBestMatch.handlerMethod.getMethod();
                    throw new IllegalStateException(
                            "Ambiguous handler methods mapped for HTTP path '" + request.getRequestURL() + "': {" +
                            m1 + ", " + m2 + "}");
                }
            }
            handleMatch(bestMatch.mapping, lookupPath, request);
            return bestMatch.handlerMethod;
        }
        else {
            return handleNoMatch(handlerMethods.keySet(), lookupPath, request);
        }
    }

urlmap里的值: {/record/test=[{[/record/test],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}], /record/showone/{pd}=[{[/record/showone/{pd}],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}], /record/show20/{pageno}=[{[/record/show20/{pageno}],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}], /record/search/{title}=[{[/record/search/{title}],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}]}

directPathMatches 里:

[{[/record/test],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}]

 

再看看初始化时候的

    @Override
    public void afterPropertiesSet() {
        initHandlerMethods();
    }

    /**
     * Scan beans in the ApplicationContext, detect and register handler methods.
     * @see #isHandler(Class)
     * @see #getMappingForMethod(Method, Class)
     * @see #handlerMethodsInitialized(Map)
     */
    protected void initHandlerMethods() {
        if (logger.isDebugEnabled()) {
            logger.debug("Looking for request mappings in application context: " + getApplicationContext());
        }

        String[] beanNames = (this.detectHandlerMethodsInAncestorContexts ?
                BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
                getApplicationContext().getBeanNamesForType(Object.class));

        for (String beanName : beanNames) {
            if (!beanName.startsWith(SCOPED_TARGET_NAME_PREFIX) &&
                    isHandler(getApplicationContext().getType(beanName))){
                detectHandlerMethods(beanName);
            }
        }
        handlerMethodsInitialized(getHandlerMethods());
    }

detectHandlerMethods 里调用registerHandlerMethod

protected void registerHandlerMethod(Object handler, Method method, T mapping) {
        HandlerMethod newHandlerMethod = createHandlerMethod(handler, method);
        HandlerMethod oldHandlerMethod = this.handlerMethods.get(mapping);
        if (oldHandlerMethod != null && !oldHandlerMethod.equals(newHandlerMethod)) {
            throw new IllegalStateException("Ambiguous mapping found. Cannot map '" + newHandlerMethod.getBean() +
                    "' bean method \n" + newHandlerMethod + "\nto " + mapping + ": There is already '" +
                    oldHandlerMethod.getBean() + "' bean method\n" + oldHandlerMethod + " mapped.");
        }

        this.handlerMethods.put(mapping, newHandlerMethod);
        if (logger.isInfoEnabled()) {
            logger.info("Mapped \"" + mapping + "\" onto " + newHandlerMethod);
        }

        Set<String> patterns = getMappingPathPatterns(mapping);
        for (String pattern : patterns) {
            if (!getPathMatcher().isPattern(pattern)) {
                this.urlMap.add(pattern, mapping);
            }
        }

        if (this.namingStrategy != null) {
            String name = this.namingStrategy.getName(newHandlerMethod, mapping);
            updateNameMap(name, newHandlerMethod);
        }
    }

 

再看ha.handler:

org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter

 

 

@Override
    protected ModelAndView handleInternal(HttpServletRequest request,
            HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {

        if (getSessionAttributesHandler(handlerMethod).hasSessionAttributes()) {
            // Always prevent caching in case of session attribute management.
            checkAndPrepare(request, response, this.cacheSecondsForSessionAttributeHandlers, true);
        }
        else {
            // Uses configured default cacheSeconds setting.
            checkAndPrepare(request, response, true);
        }

        // Execute invokeHandlerMethod in synchronized block if required.
        if (this.synchronizeOnSession) {
            HttpSession session = request.getSession(false);
            if (session != null) {
                Object mutex = WebUtils.getSessionMutex(session);
                synchronized (mutex) {
                    return invokeHandleMethod(request, response, handlerMethod);
                }
            }
        }

        return invokeHandleMethod(request, response, handlerMethod);
    }

 进入类中 class InvocableHandlerMethod extends HandlerMethod 

public Object invokeForRequest(NativeWebRequest request, ModelAndViewContainer mavContainer,
            Object... providedArgs) throws Exception {

        Object[] args = getMethodArgumentValues(request, mavContainer, providedArgs);
        if (logger.isTraceEnabled()) {
            StringBuilder sb = new StringBuilder("Invoking [");
            sb.append(getBeanType().getSimpleName()).append(".");
            sb.append(getMethod().getName()).append("] method with arguments ");
            sb.append(Arrays.asList(args));
            logger.trace(sb.toString());
        }
        Object returnValue = doInvoke(args);
        if (logger.isTraceEnabled()) {
            logger.trace("Method [" + getMethod().getName() + "] returned [" + returnValue + "]");
        }
        return returnValue;
    }

 

posted @ 2017-03-16 15:58  cnchengv  阅读(152)  评论(0)    收藏  举报