Java tutorial
/* * Copyright (C) 2013-2016 terasoluna.org * * 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 org.terasoluna.gfw.web.codelist; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Locale; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.BeanFactoryUtils; import org.springframework.beans.factory.InitializingBean; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.util.Assert; import org.springframework.web.servlet.handler.HandlerInterceptorAdapter; import org.springframework.web.servlet.support.RequestContextUtils; import org.terasoluna.gfw.common.codelist.CodeList; import org.terasoluna.gfw.common.codelist.i18n.I18nCodeList; /** * Interceptor class for setting codelist in attribute of {@link HttpServletRequest} * <p> * Default behavior is to set all the implementation beans of {@code CodeList} in the attribute of {@link HttpServletRequest}<br> * In order to narrow down the target beans, pass the pattern (regular expression) corresponding to codelist ID of target beans * <br> * to {@link #setCodeListIdPattern(Pattern)} method. * </p> */ public class CodeListInterceptor extends HandlerInterceptorAdapter implements ApplicationContextAware, InitializingBean { /** * logger */ private static final Logger logger = LoggerFactory.getLogger(CodeListInterceptor.class); /** * list of {@link CodeList} */ private Collection<CodeList> codeLists; /** * application context */ private ApplicationContext applicationContext; /** * Pattern of Codelist IDs (Bean IDs) of codelists which are target to be set to attribute of {@link HttpServletRequest}. */ private Pattern codeListIdPattern; /** * the default locale to fall back.<br> * <p> * this locale is used if the requested locale is not found in i18nCodeList. * </p> */ private Locale fallbackTo = Locale.getDefault(); /** * Sets codelist to the attribute of {@link HttpServletRequest} * <p> * Sets codelist to the attribute of {@link HttpServletRequest} before the execution of Controller. * </p> * @see org.springframework.web.servlet.handler.HandlerInterceptorAdapter#preHandle(javax.servlet.http.HttpServletRequest, * javax.servlet.http.HttpServletResponse, java.lang.Object) * @since 5.0.1 */ @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { if (codeLists == null) { return true; } Locale locale = RequestContextUtils.getLocale(request); logger.debug("locale for I18nCodelist is '{}'.", locale); for (CodeList codeList : codeLists) { String attributeName = codeList.getCodeListId(); if (codeList instanceof I18nCodeList) { I18nCodeList i18nCodeList = (I18nCodeList) codeList; Map<String, String> codeListMap = getLocalizedCodeMap(i18nCodeList, locale); request.setAttribute(attributeName, codeListMap); } else { request.setAttribute(attributeName, codeList.asMap()); } } return true; } /** * Returns the map of codelists which match to the specified locale. * <p> * If the map of codelists which match to the specified locale does not exist, returns the map of codelists which match<br> * with fallback locale. If the map corresponding to fallback locale also does not exist, then log of WARN level is output<br> * and an empty map is returned.<br> * </p> * @param i18nCodeList International Codelist * @param requestLocale Locale of request * @return Map of codelists which match to the specified locale */ protected Map<String, String> getLocalizedCodeMap(I18nCodeList i18nCodeList, Locale requestLocale) { Map<String, String> codeListMap = i18nCodeList.asMap(requestLocale); if (codeListMap.isEmpty() && (fallbackTo != null && !fallbackTo.equals(requestLocale))) { logger.debug("There is no mapping for '{}'. fall back to '{}'.", requestLocale, fallbackTo); codeListMap = i18nCodeList.asMap(fallbackTo); if (codeListMap.isEmpty()) { logger.warn("could not fall back to '{}'.", fallbackTo); } } return codeListMap; } /** * Extracts the {@code CodeList}s which are to be set to the attribute of {@link HttpServletRequest} * <p> * Among the Beans which implement {@code CodeList} interface, extract the Codelist IDs(Bean IDs) which match<br> * with the regular expression specified in {@link #codeListIdPattern}. * </p> * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet() */ @Override public void afterPropertiesSet() { Assert.notNull(applicationContext, "applicationContext is null."); if (codeListIdPattern == null) { this.codeListIdPattern = Pattern.compile(".+"); } Map<String, CodeList> definedCodeLists = BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, CodeList.class, false, false); Map<String, CodeList> targetCodeLists = new HashMap<String, CodeList>(); for (CodeList codeList : definedCodeLists.values()) { String codeListId = codeList.getCodeListId(); if (codeListId != null) { Matcher codeListIdMatcher = codeListIdPattern.matcher(codeListId); if (codeListIdMatcher.matches()) { targetCodeLists.put(codeListId, codeList); } } } if (logger.isDebugEnabled()) { logger.debug("registered codeList : {}", targetCodeLists.keySet()); } this.codeLists = Collections.unmodifiableCollection(targetCodeLists.values()); } /** * Set the ApplicationContext. * @see org.springframework.context.ApplicationContextAware#setApplicationContext(org.springframework.context.ApplicationContext) */ @Override public void setApplicationContext(ApplicationContext applicationContext) { this.applicationContext = applicationContext; } /** * Sets Pattern (regular expression) of Codelist IDs (Bean IDs) of codelists which are target to be set to attribute of * {@link HttpServletRequest}. * <p> * Default behavior is to include all beans * </p> * @param codeListIdPattern Pattern */ public void setCodeListIdPattern(Pattern codeListIdPattern) { this.codeListIdPattern = codeListIdPattern; } /** * Sets the default locale to fall back. * <p> * this locale is used if the requested locale is not found in i18nCodeList. * </p> * @param fallbackTo default locale used if the requested locale is not found in i18nCodeList */ public void setFallbackTo(Locale fallbackTo) { this.fallbackTo = fallbackTo; } /** * Returns the list of codelists which are to be set to attribute of {@link HttpServletRequest} * @return list of codelists */ protected Collection<CodeList> getCodeLists() { return codeLists; } }