org.omnifaces.config.FacesConfigXmlSingleton Maven / Gradle / Ivy
/*
* Copyright 2020 OmniFaces
*
* 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
*
* https://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.omnifaces.config;
import static org.omnifaces.util.Beans.getReference;
import static org.omnifaces.util.Faces.getServletContext;
import static org.omnifaces.util.Faces.hasContext;
import static org.omnifaces.util.Utils.isEmpty;
import static org.omnifaces.util.Utils.parseLocale;
import static org.omnifaces.util.Xml.createDocument;
import static org.omnifaces.util.Xml.getNodeList;
import static org.omnifaces.util.Xml.getTextContent;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
/**
* Enum singleton implementation of {@link FacesConfigXml}.
*
* @author Bauke Scholtz
* @author Michele Mariotti
* @since 3.1
*/
enum FacesConfigXmlSingleton implements FacesConfigXml {
// Enum singleton -------------------------------------------------------------------------------------------------
/**
* Returns the lazily loaded enum singleton instance.
*/
INSTANCE;
// Private constants ----------------------------------------------------------------------------------------------
private static final String APP_FACES_CONFIG_XML =
"/WEB-INF/faces-config.xml";
private static final String LIB_FACES_CONFIG_XML =
"META-INF/faces-config.xml";
private static final String XPATH_RESOURCE_BUNDLE =
"application/resource-bundle";
private static final String XPATH_DEFAULT_LOCALE =
"application/locale-config/default-locale";
private static final String XPATH_SUPPORTED_LOCALE =
"application/locale-config/supported-locale";
private static final String XPATH_VAR =
"var";
private static final String XPATH_BASE_NAME =
"base-name";
private static final String ERROR_INITIALIZATION_FAIL =
"FacesConfigXml failed to initialize. Perhaps your faces-config.xml contains a typo?";
// Properties -----------------------------------------------------------------------------------------------------
private Map resourceBundles;
private List supportedLocales;
// Init -----------------------------------------------------------------------------------------------------------
/**
* Perform automatic initialization whereby the servlet context is obtained from CDI.
*/
private FacesConfigXmlSingleton() {
try {
ServletContext servletContext = hasContext() ? getServletContext() : getReference(ServletContext.class);
Element facesConfigXml = loadFacesConfigXml(servletContext).getDocumentElement();
XPath xpath = XPathFactory.newInstance().newXPath();
resourceBundles = parseResourceBundles(facesConfigXml, xpath);
supportedLocales = parseSupportedLocales(facesConfigXml, xpath);
}
catch (Exception e) {
throw new IllegalStateException(ERROR_INITIALIZATION_FAIL, e);
}
}
// Getters --------------------------------------------------------------------------------------------------------
@Override
public Map getResourceBundles() {
return resourceBundles;
}
@Override
public List getSupportedLocales() {
return supportedLocales;
}
// Helpers --------------------------------------------------------------------------------------------------------
/**
* Load, merge and return all faces-config.xml files found in the classpath
* into a single {@link Document}.
*/
private static Document loadFacesConfigXml(ServletContext context) throws IOException, SAXException {
List facesConfigURLs = new ArrayList<>();
facesConfigURLs.add(context.getResource(APP_FACES_CONFIG_XML));
facesConfigURLs.addAll(Collections.list(Thread.currentThread().getContextClassLoader().getResources(LIB_FACES_CONFIG_XML)));
return createDocument(facesConfigURLs);
}
/**
* Create and return a mapping of all resource bundle base names by var found in the given document.
* @throws XPathExpressionException
*/
private static Map parseResourceBundles(Element facesConfigXml, XPath xpath) throws XPathExpressionException {
Map resourceBundles = new LinkedHashMap<>();
NodeList resourceBundleNodes = getNodeList(facesConfigXml, xpath, XPATH_RESOURCE_BUNDLE);
for (int i = 0; i < resourceBundleNodes.getLength(); i++) {
Node node = resourceBundleNodes.item(i);
String var = xpath.compile(XPATH_VAR).evaluate(node).trim();
String baseName = xpath.compile(XPATH_BASE_NAME).evaluate(node).trim();
if (!resourceBundles.containsKey(var)) {
resourceBundles.put(var, baseName);
}
}
return Collections.unmodifiableMap(resourceBundles);
}
/**
* Create and return a list of default locale and all supported locales in same order as in the given document.
* @throws XPathExpressionException
*/
private static List parseSupportedLocales(Element facesConfigXml, XPath xpath) throws XPathExpressionException {
List supportedLocales = new ArrayList<>();
String defaultLocale = xpath.compile(XPATH_DEFAULT_LOCALE).evaluate(facesConfigXml).trim();
if (!isEmpty(defaultLocale)) {
supportedLocales.add(parseLocale(defaultLocale));
}
NodeList supportedLocaleNodes = getNodeList(facesConfigXml, xpath, XPATH_SUPPORTED_LOCALE);
for (int i = 0; i < supportedLocaleNodes.getLength(); i++) {
Locale supportedLocale = parseLocale(getTextContent(supportedLocaleNodes.item(i)));
if (!supportedLocales.contains(supportedLocale)) {
supportedLocales.add(supportedLocale);
}
}
return Collections.unmodifiableList(supportedLocales);
}
}