Java tutorial
/* * Copyright 2008-2013 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package uk.co.postoffice.spike.esi.helloworld; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.PatternMatchUtils; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes; import org.springframework.web.servlet.View; import org.springframework.web.servlet.view.RedirectView; import org.thymeleaf.spring3.view.AbstractThymeleafView; import org.thymeleaf.spring3.view.ThymeleafViewResolver; import java.util.HashMap; import java.util.Locale; import java.util.Map; import java.util.Map.Entry; import javax.servlet.http.HttpServletRequest; /** * This class extends the default ThymeleafViewResolver to facilitate rendering * template fragments (such as those used by AJAX modals or iFrames) within a * full page container should the request for that template have occurred in a * stand-alone context. * * @author Andre Azzolini (apazzolini) */ public class ThymeleafMasterLayoutViewResolver extends ThymeleafViewResolver { private final Logger LOG = LoggerFactory.getLogger(this.getClass()); /** * <p> * Prefix to be used in view names (returned by controllers) for specifying an * HTTP redirect with AJAX support. That is, if you want a redirect to be followed * by the browser as the result of an AJAX call or within an iFrame at the parent * window, you can utilize this prefix. Note that this requires a JavaScript component, * which is provided as part of BLC.js * * If the request was not performed in an AJAX / iFrame context, this method will * delegate to the normal "redirect:" prefix. * </p> * <p> * Value: <tt>ajaxredirect:</tt> * </p> */ public static final String AJAX_REDIRECT_URL_PREFIX = "ajaxredirect:"; protected Map<String, String> layoutMap = new HashMap<String, String>(); protected String fullPageLayout = "layout/fullPageLayout"; protected String iframeLayout = "layout/iframeLayout"; /* * This method is a copy of the same method in ThymeleafViewResolver, but since it is marked private, * we are unable to call it from the BroadleafThymeleafViewResolver */ protected boolean canHandle(final String viewName) { final String[] viewNamesToBeProcessed = getViewNames(); final String[] viewNamesNotToBeProcessed = getExcludedViewNames(); return ((viewNamesToBeProcessed == null || PatternMatchUtils.simpleMatch(viewNamesToBeProcessed, viewName)) && (viewNamesNotToBeProcessed == null || !PatternMatchUtils.simpleMatch(viewNamesNotToBeProcessed, viewName))); } /** * Determines which internal method to call for creating the appropriate view. If no * Broadleaf specific methods match the viewName, it delegates to the parent * ThymeleafViewResolver createView method */ @Override protected View createView(final String viewName, final Locale locale) throws Exception { if (!canHandle(viewName)) { LOG.trace("[THYMELEAF] View {" + viewName + "} cannot be handled by ThymeleafViewResolver. Passing on to the next resolver in the chain"); return null; } if (viewName.startsWith(AJAX_REDIRECT_URL_PREFIX)) { LOG.trace("[THYMELEAF] View {" + viewName + "} is an ajax redirect, and will be handled directly by BroadleafThymeleafViewResolver"); String redirectUrl = viewName.substring(AJAX_REDIRECT_URL_PREFIX.length()); return loadAjaxRedirectView(redirectUrl, locale); } return super.createView(viewName, locale); } /** * Performs a Broadleaf AJAX redirect. This is used in conjunction with BLC.js to support * doing a browser page change as as result of an AJAX call. * * @param redirectUrl * @param locale * @return * @throws Exception */ protected View loadAjaxRedirectView(String redirectUrl, final Locale locale) throws Exception { if (isAjaxRequest()) { // TODO /* // utility/blcRedirect.html <div id="blc-redirect-url" class="hidden" th:text="${blc_redirect}" th:if="${!#strings.isEmpty(blc_redirect)}"></div> */ // String viewName = "utility/blcRedirect"; // addStaticVariable("blc_redirect", redirectUrl); // return super.loadView(viewName, locale); return new RedirectView(redirectUrl, isRedirectContextRelative(), isRedirectHttp10Compatible()); } else { return new RedirectView(redirectUrl, isRedirectContextRelative(), isRedirectHttp10Compatible()); } } @Override protected View loadView(final String originalViewName, final Locale locale) throws Exception { String viewName = originalViewName; if (!isAjaxRequest()) { String longestPrefix = ""; for (Entry<String, String> entry : layoutMap.entrySet()) { String viewPrefix = entry.getKey(); String viewLayout = entry.getValue(); if (viewPrefix.length() > longestPrefix.length()) { if (originalViewName.startsWith(viewPrefix)) { longestPrefix = viewPrefix; if (!"NONE".equals(viewLayout)) { viewName = viewLayout; } } } } if (longestPrefix.equals("")) { viewName = getFullPageLayout(); } } AbstractThymeleafView view = (AbstractThymeleafView) super.loadView(viewName, locale); if (!isAjaxRequest()) { view.addStaticVariable("templateName", originalViewName); } return view; } @Override protected Object getCacheKey(String viewName, Locale locale) { return viewName + "_" + locale + "_" + isAjaxRequest(); } protected boolean isAjaxRequest() { HttpServletRequest request = null; try { request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest(); } catch (ClassCastException e) { // In portlet environments, we won't be able to cast to a ServletRequestAttributes. We don't want to // blow up in these scenarios. LOG.warn("Unable to cast to ServletRequestAttributes and the request in BroadleafRequestContext " + "was not set. This may introduce incorrect AJAX behavior."); } // If we still don't have a request object, we'll default to non-ajax if (request == null) { return false; } return isAjaxRequest(request); } private boolean isAjaxRequest(HttpServletRequest request) { String requestedWithHeader = request.getHeader("X-Requested-With"); boolean result = "XMLHttpRequest".equals(requestedWithHeader); if (LOG.isTraceEnabled()) { LOG.trace("Request URL: [" + request.getServletPath() + "]" + " - " + "X-Requested-With: [" + requestedWithHeader + "]" + " - " + "Returning: [" + result + "]"); } return result; } /** * Gets the map of prefix : layout for use in determining which layout * to dispatch the request to in non-AJAX calls * * @return the layout map */ public Map<String, String> getLayoutMap() { return layoutMap; } /** * @see #getLayoutMap() * @param layoutMap */ public void setLayoutMap(Map<String, String> layoutMap) { this.layoutMap = layoutMap; } /** * The default layout to use if there is no specifc entry in the layout map * * @return the full page layout */ public String getFullPageLayout() { return fullPageLayout; } /** * @see #getFullPageLayout() * @param fullPageLayout */ public void setFullPageLayout(String fullPageLayout) { this.fullPageLayout = fullPageLayout; } /** * The layout to use for iframe requests * * @return the iframe layout */ public String getIframeLayout() { return iframeLayout; } /** * @see #getIframeLayout() * @param iframeLayout */ public void setIframeLayout(String iframeLayout) { this.iframeLayout = iframeLayout; } }