Java tutorial
/** * Licensed to Apereo under one or more contributor license * agreements. See the NOTICE file distributed with this work * for additional information regarding copyright ownership. * Apereo licenses this file to you 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 the following location: * * 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 org.apereo.portal.portlets.backgroundpreference; import java.util.Arrays; import org.apache.commons.lang.StringUtils; import org.apereo.portal.spring.spel.IPortalSpELService; import org.apereo.portal.spring.spel.PortalSpELServiceImpl; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.expression.Expression; import org.springframework.expression.spel.support.StandardEvaluationContext; import org.springframework.stereotype.Component; import javax.annotation.PostConstruct; import javax.portlet.ActionRequest; import javax.portlet.PortletPreferences; import javax.portlet.PortletRequest; import javax.servlet.ServletContext; /** * Determines set of images to display by checking to see if user is in a mobile user group as determined by the * portal's security roles. * * @author James Wennmacher, jwennmacher@unicon.net */ @Component public class RoleBasedBackgroundSetSelectionStrategy implements BackgroundSetSelectionStrategy { private enum PreferenceNames { DEFAULT("default"), MOBILE("mobile"); /** * <b>Must match</a> the name of the corresponding PAGS group perfectly. */ private static final String MOBILE_DEVICE_ROLE_NAME = "Mobile Device Access"; public static PreferenceNames getInstance(PortletRequest req) { return req.isUserInRole(MOBILE_DEVICE_ROLE_NAME) ? MOBILE : DEFAULT; } private final String prefix; private PreferenceNames(String prefix) { this.prefix = prefix; } public String getImageSetPreferenceName() { return prefix + "BackgroundImages"; } public String getImageThumbnailSetPreferenceName() { return prefix + "BackgroundThumbnailImages"; } public String getSelectedBackgroundImagePreferenceName() { return prefix + "SelectedBackgroundImage"; } public String getBackgroundContainerSelectorPreferenceName() { return prefix + "BackgroundContainerSelector"; } } private static final String[] EMPTY_STRING_ARRAY = new String[0]; @Autowired private ServletContext servletContext; @Autowired private IPortalSpELService portalSpELService; final StandardEvaluationContext evaluationContext = new StandardEvaluationContext(); @PostConstruct public void init() { final String contextPath = servletContext.getContextPath(); evaluationContext.setRootObject(new RootObjectImpl(contextPath)); } @Override public String[] getImageSet(PortletRequest req) { final PreferenceNames names = PreferenceNames.getInstance(req); final PortletPreferences prefs = req.getPreferences(); final String[] images = prefs.getValues(names.getImageSetPreferenceName(), EMPTY_STRING_ARRAY); for (int i = 0; i < images.length; i++) { images[i] = evaluateImagePath(images[i]); } return images; } @Override public String[] getImageThumbnailSet(PortletRequest req) { PreferenceNames names = PreferenceNames.getInstance(req); PortletPreferences prefs = req.getPreferences(); final String[] images = prefs.getValues(names.getImageThumbnailSetPreferenceName(), null); for (int i = 0; i < images.length; i++) { images[i] = evaluateImagePath(images[i]); } return images; } @Override public String getSelectedImage(PortletRequest req) { // No evaluation required (already processed) PreferenceNames names = PreferenceNames.getInstance(req); PortletPreferences prefs = req.getPreferences(); return prefs.getValue(names.getSelectedBackgroundImagePreferenceName(), null); } @Override public String getBackgroundContainerSelector(PortletRequest req) { PreferenceNames names = PreferenceNames.getInstance(req); PortletPreferences prefs = req.getPreferences(); return prefs.getValue(names.getBackgroundContainerSelectorPreferenceName(), null); } @Override public void setSelectedImage(ActionRequest req, String backgroundImage) { PreferenceNames names = PreferenceNames.getInstance(req); PortletPreferences prefs = req.getPreferences(); if (StringUtils.isNotBlank(backgroundImage)) { // We are trying to choose a background; first verify the requested image is actually in the set... String[] images = prefs.getValues(names.getImageSetPreferenceName(), EMPTY_STRING_ARRAY); for (int i = 0; i < images.length; i++) { images[i] = evaluateImagePath(images[i]); } if (Arrays.asList(images).contains(backgroundImage)) { try { prefs.setValue(names.getSelectedBackgroundImagePreferenceName(), backgroundImage); prefs.store(); } catch (Exception e) { throw new RuntimeException("Failed to store the user's choice of background image", e); } } } else { // We are trying to clear a previous selection try { prefs.reset(names.getSelectedBackgroundImagePreferenceName()); prefs.store(); } catch (Exception e) { throw new RuntimeException("Failed to reset the user's choice of background image", e); } } } /* * Implementation */ private String evaluateImagePath(String pathBeforeProcessing) { final Expression x = portalSpELService.parseExpression(pathBeforeProcessing, PortalSpELServiceImpl.TemplateParserContext.INSTANCE); final String rslt = x.getValue(evaluationContext, String.class); return rslt; } /* * Nested Types */ /** * Allows us to evaluate '${portalContext}' to '/uPortal' (or whatever it * is) within image paths. */ private static final class RootObjectImpl { private final String portalContext; public RootObjectImpl(String portalContext) { this.portalContext = portalContext; } @SuppressWarnings("unused") public String getPortalContext() { return portalContext; } } }