/*
* [The "BSD licence"]
* Copyright (c) 2013-2014 Dandelion
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Dandelion nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.github.dandelion.datatables.core.configuration;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.Properties;
import javax.servlet.http.HttpServletRequest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.github.dandelion.core.utils.ClassUtils;
import com.github.dandelion.core.utils.StringUtils;
import com.github.dandelion.datatables.core.constants.SystemConstants;
import com.github.dandelion.datatables.core.exception.ConfigurationLoadingException;
import com.github.dandelion.datatables.core.generator.javascript.JavascriptGenerator;
import com.github.dandelion.datatables.core.generator.javascript.StandardJavascriptGenerator;
import com.github.dandelion.datatables.core.i18n.LocaleResolver;
import com.github.dandelion.datatables.core.i18n.MessageResolver;
import com.github.dandelion.datatables.core.i18n.StandardLocaleResolver;
/**
* <p>
* The {@link DatatablesConfigurator} is used to pick up different classes in
* charge of the configuration loading, instantiate them and cache them.
*
* <ul>
* <li>The locale resolver, in charge of retrieving the current locale from
* which the configuration will be loaded</li>
* <li>The configuration loader, in charge of loading default and user
* properties and resolve configurations groups</li>
* </ul>
* <p>
*
* @author Thibault Duchateau
* @since 0.9.0
* @see LocaleResolver
* @see StandardLocaleResolver
* @see ConfigurationLoader
* @see StandardConfigurationLoader
*/
public class DatatablesConfigurator {
// Logger
private static Logger logger = LoggerFactory.getLogger(DatatablesConfigurator.class);
private static ConfigurationLoader configurationLoader;
private static LocaleResolver localeResolver;
private static MessageResolver messageResolver;
/**
* Return a uniq implementation of {@link LocaleResolver} using the
* following strategy:
*
* <ol>
* <li>First, check if the <code>i18n.locale.resolver</code> has been
* defined in any of the user properties files. If so, tries to instantiate
* the class.</li>
* <li>If no specific LocaleResolver is defined in user properties, the
* default will be used</li>
* </ol>
*
* @return an implementation {@link LocaleResolver}.
*/
@SuppressWarnings("unchecked")
public static LocaleResolver getLocaleResolver() {
Properties userProperties = null;
String className = null;
ConfigurationLoader configurationLoader = getConfigurationLoader();
if (localeResolver == null) {
try {
userProperties = configurationLoader.loadUserConfiguration(Locale.getDefault());
if(userProperties != null){
try {
className = userProperties.getProperty("i18n.locale.resolver");
} catch (MissingResourceException e) {
logger.debug("No custom LocaleResolver has been configured. Using default one.");
}
}
if(className == null){
Properties defaultProperties = configurationLoader.loadDefaultConfiguration();
className = defaultProperties.getProperty("i18n.locale.resolver");
}
if (className != null) {
Class<LocaleResolver> classProperty;
try {
classProperty = (Class<LocaleResolver>) ClassUtils.getClass(className);
localeResolver = (LocaleResolver) ClassUtils.getNewInstance(classProperty);
} catch (Exception e) {
throw new ConfigurationLoadingException(e);
}
}
} catch (ConfigurationLoadingException e) {
throw new ConfigurationLoadingException("Unable to retrieve the LocaleResolver using the class '"
+ className + "'", e);
}
}
return localeResolver;
}
@SuppressWarnings("unchecked")
public static MessageResolver getMessageResolver(HttpServletRequest request) {
Properties userProperties = null;
String className = null;
ConfigurationLoader configurationLoader = getConfigurationLoader();
if (messageResolver == null) {
try {
userProperties = configurationLoader.loadUserConfiguration(Locale.getDefault());
if(userProperties != null){
try {
className = userProperties.getProperty("i18n.message.resolver");
} catch (MissingResourceException e) {
logger.debug("No custom MessageResolver has been configured. Using default one.");
}
}
if(className == null){
Properties defaultProperties = configurationLoader.loadDefaultConfiguration();
className = defaultProperties.getProperty("i18n.message.resolver");
}
if (className != null) {
Class<MessageResolver> classProperty;
try {
classProperty = (Class<MessageResolver>) ClassUtils.getClass(className);
messageResolver = classProperty.getDeclaredConstructor(new Class[] { HttpServletRequest.class })
.newInstance(request);
} catch (Exception e) {
throw new ConfigurationLoadingException(e);
}
}
} catch (ConfigurationLoadingException e) {
throw new ConfigurationLoadingException("Unable to retrieve the MessageResolver using the class '"
+ className + "'", e);
}
}
return messageResolver;
}
/**
* <p>
* Returns an implementation of {@link ConfigurationLoader} using the
* following strategy:
* <ol>
* <li>Check first if the <code>dandelion.datatables.confloader.class</code>
* system property is set and tries to instantiate it</li>
* <li>Otherwise, instantiate the {@link StandardConfigurationLoader} based
* on property files</li>
* </ol>
*
* @return an implementation of {@link ConfigurationLoader}.
*/
public static ConfigurationLoader getConfigurationLoader() {
if (configurationLoader == null) {
logger.debug("Initializing the configuration loader...");
if (StringUtils.isNotBlank(System.getProperty(SystemConstants.DANDELION_DT_CONFLOADER_CLASS))) {
Class<?> clazz;
try {
clazz = ClassUtils.getClass(System.getProperty(SystemConstants.DANDELION_DT_CONFLOADER_CLASS));
configurationLoader = (ConfigurationLoader) ClassUtils.getNewInstance(clazz);
} catch (Exception e) {
logger.warn(
"Unable to instantiate the configured {} due to a {} exception. Falling back to the default one.",
SystemConstants.DANDELION_DT_CONFLOADER_CLASS, e.getClass().getName(), e);
}
}
if (configurationLoader == null) {
configurationLoader = new StandardConfigurationLoader();
}
}
return configurationLoader;
}
/**
* <p>
* Returns an implementation of {@link JavascriptGenerator} using the
* following strategy:
* <ol>
* <li>Check first if the
* <code>dandelion.datatables.js.generator.class</code> system property is
* set and tries to instantiate it</li>
* <li>Otherwise, instantiate the {@link StandardJavascriptGenerator} based
* on property files</li>
* </ol>
*
* @return an implementation of {@link JavascriptGenerator}.
*/
public static JavascriptGenerator getJavascriptGenerator() {
logger.debug("Initializing the Javascript generator...");
JavascriptGenerator javascriptGenerator = null;
if (StringUtils.isNotBlank(System.getProperty(SystemConstants.DANDELION_DT_JS_GEN_CLASS))) {
Class<?> clazz;
try {
clazz = ClassUtils.getClass(System.getProperty(SystemConstants.DANDELION_DT_JS_GEN_CLASS));
javascriptGenerator = (JavascriptGenerator) ClassUtils.getNewInstance(clazz);
} catch (Exception e) {
logger.warn(
"Unable to instantiate the configured {} due to a {} exception. Falling back to the default one.",
SystemConstants.DANDELION_DT_JS_GEN_CLASS, e.getClass().getName(), e);
}
}
if (javascriptGenerator == null) {
javascriptGenerator = new StandardJavascriptGenerator();
}
return javascriptGenerator;
}
/**
* <b>FOR INTERNAL USE ONLY</b>
*/
public static void clear() {
configurationLoader = null;
localeResolver = null;
}
}