/*
* $Id: CachingLocaleUrlDefinitionDAO.java 795343 2009-07-18 11:26:09Z apetrelli $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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
*
* 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.apache.tiles.definition.dao;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Map;
import org.apache.tiles.Definition;
import org.apache.tiles.definition.DefinitionsFactoryException;
import org.apache.tiles.definition.NoSuchDefinitionException;
import org.apache.tiles.definition.Refreshable;
import org.apache.tiles.definition.pattern.BasicPatternDefinitionResolver;
import org.apache.tiles.definition.pattern.PatternDefinitionResolver;
import org.apache.tiles.definition.pattern.PatternDefinitionResolverAware;
import org.apache.tiles.definition.pattern.wildcard.WildcardDefinitionPatternMatcherFactory;
import org.apache.tiles.util.LocaleUtil;
/**
* <p>
* A definitions DAO (loading URLs and using Locale as a customization key) that
* caches definitions that have been loaded in a raw way (i.e. with inheritance
* that is not resolved).
* </p>
* <p>
* It can check if the URLs change, but by default this feature is turned off.
* </p>
*
* @version $Rev: 795343 $ $Date: 2009-07-18 13:26:09 +0200 (sab, 18 lug 2009) $
* @since 2.1.0
*/
public class CachingLocaleUrlDefinitionDAO extends BaseLocaleUrlDefinitionDAO
implements Refreshable, PatternDefinitionResolverAware<Locale> {
/**
* Initialization parameter to set whether we want to refresh URLs when they
* change.
*
* @since 2.1.0
*/
public static final String CHECK_REFRESH_INIT_PARAMETER =
"org.apache.tiles.definition.dao.LocaleUrlDefinitionDAO.CHECK_REFRESH";
/**
* The locale-specific set of definitions objects.
*
* @since 2.1.0
*/
protected Map<Locale, Map<String, Definition>> locale2definitionMap;
/**
* Flag that, when <code>true</code>, enables automatic checking of URLs
* changing.
*
* @since 2.1.0
*/
protected boolean checkRefresh = false;
/**
* Resolves definitions using patterns.
*
* @since 2.2.0
*/
protected PatternDefinitionResolver<Locale> definitionResolver;
/**
* Constructor.
*
* @since 2.1.0
*/
public CachingLocaleUrlDefinitionDAO() {
locale2definitionMap = new HashMap<Locale, Map<String, Definition>>();
}
/** {@inheritDoc} */
@Override
public void init(Map<String, String> params) {
super.init(params);
String param = params.get(CHECK_REFRESH_INIT_PARAMETER);
checkRefresh = "true".equals(param);
WildcardDefinitionPatternMatcherFactory definitionPatternMatcherFactory =
new WildcardDefinitionPatternMatcherFactory();
definitionResolver = new BasicPatternDefinitionResolver<Locale>(
definitionPatternMatcherFactory,
definitionPatternMatcherFactory);
}
/** {@inheritDoc} */
public void setPatternDefinitionResolver(
PatternDefinitionResolver<Locale> definitionResolver) {
this.definitionResolver = definitionResolver;
}
/** {@inheritDoc} */
public Definition getDefinition(String name, Locale customizationKey) {
Definition retValue = null;
if (customizationKey == null) {
customizationKey = LocaleUtil.NULL_LOCALE;
}
Map<String, Definition> definitions = getDefinitions(customizationKey);
if (definitions != null) {
retValue = definitions.get(name);
if (retValue == null) {
retValue = definitionResolver.resolveDefinition(name,
customizationKey);
if (retValue != null) {
try {
synchronized (definitions) {
definitions.put(name, retValue);
}
} catch (NoSuchDefinitionException ex) {
throw new IllegalStateException(
"Unable to resolve wildcard mapping", ex);
}
}
}
}
return retValue;
}
/** {@inheritDoc} */
public Map<String, Definition> getDefinitions(Locale customizationKey) {
if (customizationKey == null) {
customizationKey = LocaleUtil.NULL_LOCALE;
}
Map<String, Definition> retValue = locale2definitionMap
.get(customizationKey);
if (retValue == null || (checkRefresh && refreshRequired())) {
retValue = checkAndloadDefinitions(customizationKey);
}
return retValue;
}
/** {@inheritDoc} */
public synchronized void refresh() {
if (refreshRequired()) {
locale2definitionMap.clear();
}
}
/**
* Sets the flag to check URL refresh. If not called, the default is
* <code>false</code>.
*
* @param checkRefresh When <code>true</code>, enables automatic checking
* of URLs changing.
* @since 2.1.0
*/
public void setCheckRefresh(boolean checkRefresh) {
this.checkRefresh = checkRefresh;
}
/**
* Checks if URLs have changed. If yes, it clears the cache. Then continues
* loading definitions.
*
* @param customizationKey The locale to use when loading URLs.
* @return The loaded definitions.
* @since 2.1.0
*/
protected synchronized Map<String, Definition> checkAndloadDefinitions(
Locale customizationKey) {
if (checkRefresh && refreshRequired()) {
locale2definitionMap.clear();
}
return loadDefinitions(customizationKey);
}
/**
* Tries to load definitions if necessary.
*
* @param customizationKey The locale to use when loading URLs.
* @return The loaded definitions.
* @since 2.1.0
*/
protected Map<String, Definition> loadDefinitions(Locale customizationKey) {
Map<String, Definition> localeDefsMap = locale2definitionMap
.get(customizationKey);
if (localeDefsMap != null) {
return localeDefsMap;
}
localeDefsMap = loadDefinitionsFromURLs(customizationKey);
return localeDefsMap;
}
/**
* Loads definitions from the URLs.
*
* @param customizationKey The locale to use when loading URLs.
* @return The loaded definitions.
* @since 2.1.0
*/
protected Map<String, Definition> loadDefinitionsFromURLs(Locale customizationKey) {
Map<String, Definition> localeDefsMap = loadRawDefinitionsFromURLs(customizationKey);
postDefinitionLoadOperations(localeDefsMap, customizationKey);
return localeDefsMap;
}
/**
* Loads the raw definitions from the URLs associated with a locale.
*
* @param customizationKey The locale to use when loading URLs.
* @return The loaded definitions.
* @since 2.1.3
*/
protected Map<String, Definition> loadRawDefinitionsFromURLs(
Locale customizationKey) {
Map<String, Definition> localeDefsMap;
String postfix = LocaleUtil.calculatePostfix(customizationKey);
Locale parentLocale = LocaleUtil.getParentLocale(customizationKey);
localeDefsMap = new LinkedHashMap<String, Definition>();
if (parentLocale != null) {
Map<String, Definition> parentDefs = loadParentDefinitions(parentLocale);
if (parentDefs != null) {
localeDefsMap.putAll(parentDefs);
}
}
// For each source, the URL must be loaded.
for (URL url : sourceURLs) {
String path = url.toExternalForm();
String newPath = LocaleUtil.concatPostfix(path, postfix);
try {
URL newUrl = new URL(newPath);
Map<String, Definition> defsMap = loadDefinitionsFromURL(newUrl);
if (defsMap != null) {
localeDefsMap.putAll(defsMap);
}
} catch (MalformedURLException e) {
throw new DefinitionsFactoryException("Error parsing URL "
+ newPath, e);
}
}
locale2definitionMap.put(customizationKey, localeDefsMap);
return localeDefsMap;
}
/**
* Loads parent definitions, i.e. definitions mapped to a parent locale.
*
* @param parentLocale The locale to use when loading URLs.
* @return The loaded parent definitions.
* @since 2.1.0
*/
protected Map<String, Definition> loadParentDefinitions(Locale parentLocale) {
return loadDefinitions(parentLocale);
}
/**
* Operations to be done after definitions are loaded.
*
* @param localeDefsMap The loaded definitions.
* @param customizationKey The locale to use when loading URLs.
* @since 2.1.0
*/
protected void postDefinitionLoadOperations(
Map<String, Definition> localeDefsMap, Locale customizationKey) {
definitionResolver.storeDefinitionPatterns(localeDefsMap, customizationKey);
}
}