設計模式的引用列舉（我遇到的寫在這裏，不作專門的總結）

一、模板方法設計模式

（1）shiro中受權與訪問控制

父類AuthorizingRealm方法（模板方法）

protected AuthorizationInfo getAuthorizationInfo(PrincipalCollection principals) {
    if(principals == null) {
        return null;
    } else {
        AuthorizationInfo info = null;
        if(log.isTraceEnabled()) {
            log.trace("Retrieving AuthorizationInfo for principals [" + principals + "]");
        }

        Cache cache = this.getAvailableAuthorizationCache();
        Object key;
        if(cache != null) {
            if(log.isTraceEnabled()) {
                log.trace("Attempting to retrieve the AuthorizationInfo from cache.");
            }

            key = this.getAuthorizationCacheKey(principals);
            info = (AuthorizationInfo)cache.get(key);
            if(log.isTraceEnabled()) {
                if(info == null) {
                    log.trace("No AuthorizationInfo found in cache for principals [" + principals + "]");
                } else {
                    log.trace("AuthorizationInfo found in cache for principals [" + principals + "]");
                }
            }
        }

        if(info == null) {
            //這是一個抽象方法，要求子類重寫
            info = this.doGetAuthorizationInfo(principals);
            if(info != null && cache != null) {
                if(log.isTraceEnabled()) {
                    log.trace("Caching authorization info for principals: [" + principals + "].");
                }

                key = this.getAuthorizationCacheKey(principals);
                cache.put(key, info);
            }
        }

        return info;
    }
}

抽象方法以下

protected abstract AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection var1);

（2）SpringMVC中的DispatcherServlet extends FramworkServlet

模版方法

protected final void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    long startTime = System.currentTimeMillis();
    Object failureCause = null;
    LocaleContext previousLocaleContext = LocaleContextHolder.getLocaleContext();
    LocaleContext localeContext = this.buildLocaleContext(request);
    RequestAttributes previousAttributes = RequestContextHolder.getRequestAttributes();
    ServletRequestAttributes requestAttributes = this.buildRequestAttributes(request, response, previousAttributes);
    WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
    asyncManager.registerCallableInterceptor(FrameworkServlet.class.getName(), new FrameworkServlet.RequestBindingInterceptor(null));
    this.initContextHolders(request, localeContext, requestAttributes);

    try {
        //抽象方法，在DispatherServlet中被實現
        this.doService(request, response);
    } catch (ServletException var17) {
        failureCause = var17;
        throw var17;
    } catch (IOException var18) {
        failureCause = var18;
        throw var18;
    } catch (Throwable var19) {
        failureCause = var19;
        throw new NestedServletException("Request processing failed", var19);
    } finally {
        this.resetContextHolders(request, previousLocaleContext, previousAttributes);
        if(requestAttributes != null) {
            requestAttributes.requestCompleted();
        }

        if(this.logger.isDebugEnabled()) {
            if(failureCause != null) {
                this.logger.debug("Could not complete request", (Throwable)failureCause);
            } else if(asyncManager.isConcurrentHandlingStarted()) {
                this.logger.debug("Leaving response open for concurrent processing");
            } else {
                this.logger.debug("Successfully completed request");
            }
        }

        this.publishRequestHandledEvent(request, startTime, (Throwable)failureCause);
    }

}

//抽象方法
protected abstract void doService(HttpServletRequest var1, HttpServletResponse var2) throws Exception;