Java tutorial
/******************************************************************************* * Copyright 2008(c) The OBiBa Consortium. All rights reserved. * * This program and the accompanying materials * are made available under the terms of the GNU Public License v3.0. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. ******************************************************************************/ package org.obiba.onyx.spring.context; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Locale; import java.util.Properties; import java.util.Set; import java.util.TreeSet; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.FactoryBean; import org.springframework.context.MessageSource; import org.springframework.context.ResourceLoaderAware; import org.springframework.context.support.ReloadableResourceBundleMessageSource; import org.springframework.context.support.StaticMessageSource; import org.springframework.core.io.Resource; import org.springframework.core.io.ResourceLoader; import org.springframework.core.io.support.ResourcePatternResolver; import com.google.common.collect.Maps; /** * A {@code FactoryBean} that creates a special {@code MessageSource} compatible with Onyx's module structure. * <p> * A {@code MessageSource} is created by finding all bundles that respect Onyx's naming convention: * * <pre> * onyxConfigPath/<module>/messages_<locale>.{properties,xml} * </pre> * * <p> * Another {@code MessageSource} is created by finding all the bundles named "META-INF/messages" on the classpath. This * allows loading bundles from the module's jar files. This new {@code MessageSource} is set as the first's * {@code parent}. This allows overriding the default messages by re-defining the same kay in the bundles in the * configuration files. * <p> * Extra bundles may be configured using the {@code extraBasenames} property. */ public class OnyxMessageSourceFactoryBean implements FactoryBean, ResourceLoaderAware { private static final Logger log = LoggerFactory.getLogger(OnyxMessageSourceFactoryBean.class); private static final String MESSAGES_BUNDLENAME = "messages"; private static final String MESSAGES_PROPERTIES_SUFFIX = ".properties"; private static final String MESSAGES_XML_SUFFIX = ".xml"; private ResourceLoader resourceLoader; private String onyxConfigPath; private Set<String> extraBasenames; public void setOnyxConfigPath(String onyxConfigPath) { this.onyxConfigPath = onyxConfigPath; if (this.onyxConfigPath.endsWith("/") == false) { this.onyxConfigPath = this.onyxConfigPath + "/"; } } public void setExtraBasenames(Set<String> extraBasenames) { this.extraBasenames = extraBasenames; } public void setResourceLoader(ResourceLoader resourceLoader) { this.resourceLoader = resourceLoader; } public Object getObject() throws Exception { ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource(); messageSource.setResourceLoader(resourceLoader); Set<String> basenames = new TreeSet<String>(); if (this.resourceLoader instanceof ResourcePatternResolver) { findBasenames(basenames, MESSAGES_PROPERTIES_SUFFIX); findBasenames(basenames, MESSAGES_XML_SUFFIX); } if (extraBasenames != null) { basenames.addAll(extraBasenames); } String[] basenamesArray = basenames.toArray(new String[] {}); log.debug("MessageSource contains the following basenames: {}", Arrays.toString(basenamesArray)); messageSource.setBasenames(basenamesArray); MessageSource moduleMessageSource = loadJarBundles(); messageSource.setParentMessageSource(moduleMessageSource); return new StringReferenceFormatingMessageSource(messageSource); } public Class<?> getObjectType() { return MessageSource.class; } public boolean isSingleton() { return true; } protected void findBasenames(Set<String> basenames, String suffix) throws IOException { ResourcePatternResolver resolver = (ResourcePatternResolver) this.resourceLoader; // Find all files that match "pathPrefix/**/MESSAGES_BASENAME*suffix" // For example, this will find "WEB-INF/config/myModule/messages_en.properties" String resourcePattern = onyxConfigPath + "**/" + MESSAGES_BUNDLENAME + "*" + suffix; String resourcePatternParent = onyxConfigPath + MESSAGES_BUNDLENAME + "*" + suffix; log.debug("Finding resources that match pattern {}", resourcePattern); List<Resource> messageResources = new ArrayList<Resource>(); messageResources.addAll(Arrays.asList(resolver.getResources(resourcePattern))); messageResources.addAll(Arrays.asList(resolver.getResources(resourcePatternParent))); for (Resource resource : messageResources) { String basename = resolveBasename(resource); log.debug("Basename for bundle resource {} resolved as {}", resource.getDescription(), basename); if (basename != null) { basenames.add(basename); } } } protected String resolveBasename(Resource bundleResource) { // Resource#getFilename() does not return the full path. As such, we must get the underlying File instance. // Since all Resource instances are not File instances, this will only work with resources on the filesystem. File bundleFile; try { bundleFile = bundleResource.getFile(); } catch (IOException e) { log.info("Cannot add resource {} to MessageSource because it is not on the filesystem.", bundleResource.getDescription()); return null; } String filename = bundleFile.getAbsolutePath(); // Make file pathname compatible with Spring's pathnames (if necessary) if (File.separatorChar != '/') { filename = filename.replace(File.separatorChar, '/'); } StringBuilder basename = new StringBuilder(filename); // Find the last part that fits the bundle's name int basenameIndex = basename.lastIndexOf(MESSAGES_BUNDLENAME); int length = basename.length(); // Delete anything appearing after the bundle's name basename.delete(basenameIndex + MESSAGES_BUNDLENAME.length(), length); return "file:" + basename.toString(); } protected MessageSource loadJarBundles() throws IOException { ResourcePatternResolver resolver = (ResourcePatternResolver) this.resourceLoader; String bundlePattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + "META-INF/" + MESSAGES_BUNDLENAME + "*" + MESSAGES_PROPERTIES_SUFFIX; Resource[] messageResources = resolver.getResources(bundlePattern); StaticMessageSource sms = new StaticMessageSource(); for (int i = 0; i < messageResources.length; i++) { Resource resource = messageResources[i]; Locale locale = extractLocale(resource, MESSAGES_PROPERTIES_SUFFIX); log.debug("Found module bundle resource {} with locale {}", resource.getDescription(), locale); Properties props = new Properties(); props.load(resource.getInputStream()); sms.addMessages(Maps.fromProperties(props), locale); } return sms; } protected Locale extractLocale(Resource resource, String suffix) { String filename = resource.getFilename(); StringBuilder locale = new StringBuilder(filename); // Find the last part that fits the bundle's name int basenameIndex = filename.lastIndexOf(MESSAGES_BUNDLENAME); int length = MESSAGES_BUNDLENAME.length(); // Remove everything before the basename, the basename and one more char to eat the '_' locale.delete(0, basenameIndex + length + 1); int suffixIndex = locale.lastIndexOf(suffix); locale.delete(suffixIndex, locale.length()); return new Locale(locale.toString()); } }