/*
* $Header: /home/cvs/jakarta-struts/src/tiles-documentation/org/apache/struts/webapp/tiles/channel/ChannelFactorySet.java,v 1.7 2004/06/24 01:07:23 jmitchell Exp $
* $Revision: 1.7 $
* $Date: 2004/06/24 01:07:23 $
*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.apache.struts.webapp.tiles.channel;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.tiles.DefinitionsFactoryException;
import org.apache.struts.tiles.FactoryNotFoundException;
import org.apache.struts.tiles.xmlDefinition.DefinitionsFactory;
import org.apache.struts.tiles.xmlDefinition.FactorySet;
import org.apache.struts.tiles.xmlDefinition.XmlDefinitionsSet;
import org.apache.struts.tiles.xmlDefinition.XmlParser;
import org.xml.sax.SAXException;
/**
* Component Definitions factory.
* This implementation of Component Definitions factory allows i18n
* Component definitions factory allowing i18n definition.
* A definition is retrieved by its name, and using locale setted in appropriate
* session context. Definitions are defined in different files, one for each locale.
* A definition file is loaded using common name extended with locale code
* (ex : templateDefinitions_fr.xml). If no file is found under this name, use default
* file.
*/
public class ChannelFactorySet extends FactorySet {
private static final Log log = LogFactory.getLog(ChannelFactorySet.class);
/**
* Debug flag.
* @deprecated This will be removed in a release after Struts 1.2.
*/
public static final boolean debug = false;
/**
* Default name.
*/
public static final String DEFAULT_DEFINITIONS_FILE_NAME =
"/WEB-INF/templateDefinitions.xml";
/**
* Config file parameter name.
*/
public static final String DEFINITIONS_CONFIG_PARAMETER_NAME =
"definitions-config";
/**
* Config file parameter name.
*/
public static final String FACTORY_SELECTOR_KEY =
"ChannelFactorySet.factorySelectorKey";
/**
* Default filenames extension.
*/
public static final String FILENAME_EXTENSION = ".xml";
/**
* Default factory.
*/
protected DefinitionsFactory defaultFactory = null;
/**
* Xml parser used.
*/
protected XmlParser xmlParser = null;
/**
* Names of default file containing definition descriptions.
*/
private String filename = null;
/**
* Collection of already loaded definitions set, referenced by their suffix.
*/
private Map loaded = null;
/**
* Parameterless Constructor.
* Method initFactory must be called prior to any use of created factory.
*/
public ChannelFactorySet() {
super();
}
/**
* Constructor.
* Init the factory by reading appropriate configuration file.
* @throws FactoryNotFoundException Can't find factory configuration file.
*/
public ChannelFactorySet(ServletContext servletContext, Map properties)
throws DefinitionsFactoryException {
initFactory(servletContext, properties);
}
/**
* Initialization method.
* Init the factory by reading appropriate configuration file.
* This method is called exactly once immediately after factory creation in
* case of internal creation (by DefinitionUtil).
* @param servletContext Servlet Context passed to newly created factory.
* @param properties Map of name/property passed to newly created factory. Map can contains
* more properties than requested.
* @throws DefinitionsFactoryException An error occur during initialization.
*/
public void initFactory(ServletContext servletContext, Map properties)
throws DefinitionsFactoryException {
// read properties values
String proposedFilename =
(String) properties.get(DEFINITIONS_CONFIG_PARAMETER_NAME);
// Compute filenames to use
boolean isFileSpecified = true;
if (proposedFilename == null) {
proposedFilename = DEFAULT_DEFINITIONS_FILE_NAME;
isFileSpecified = false;
}
try {
initFactory(servletContext, proposedFilename);
return;
} catch (FileNotFoundException ex) {
// If a filename is specified, throw appropriate error.
if (isFileSpecified) {
throw new FactoryNotFoundException(
ex.getMessage()
+ " : Can't find file '"
+ proposedFilename
+ "'");
}
}
}
/**
* Initialization method.
* Init the factory by reading appropriate configuration file.
* This method is called exactly once immediately after factory creation in
* case of internal creation (by DefinitionUtil).
* @param servletContext Servlet Context passed to newly created factory.
* @param proposedFilename File names, comma separated, to use as base file names.
* @throws DefinitionsFactoryException An error occur during initialization.
*/
protected void initFactory(
ServletContext servletContext,
String proposedFilename)
throws DefinitionsFactoryException, FileNotFoundException {
filename = proposedFilename;
loaded = new HashMap();
defaultFactory = createDefaultFactory(servletContext);
}
/**
* Get default factory.
* @return Default factory
*/
protected DefinitionsFactory getDefaultFactory() {
return defaultFactory;
}
/**
* Create default factory .
* @param servletContext Current servlet context. Used to open file.
* @return Created default definition factory.
* @throws DefinitionsFactoryException If an error occur while creating factory.
* @throws FileNotFoundException if factory can't be loaded from filenames.
*/
protected DefinitionsFactory createDefaultFactory(ServletContext servletContext)
throws DefinitionsFactoryException, FileNotFoundException {
XmlDefinitionsSet rootXmlConfig = parseXmlKeyFile(servletContext, "", null);
if (rootXmlConfig == null) {
throw new FileNotFoundException();
}
rootXmlConfig.resolveInheritances();
return new DefinitionsFactory(rootXmlConfig);
}
/**
* Extract key that will be used to get the sub factory.
* @param name Name of requested definition
* @param request Current servlet request.
* @param servletContext Current servlet context
* @return the key or null if not found.
* @roseuid 3AF6F887018A
*/
protected Object getDefinitionsFactoryKey(
String name,
ServletRequest request,
ServletContext servletContext) {
Object key = null;
HttpSession session = ((HttpServletRequest) request).getSession(false);
if (session != null) {
key = session.getAttribute(FACTORY_SELECTOR_KEY);
}
return key;
}
/**
* Create a factory for specified key.
* If creation failed, return default factory, and output an error message in
* console.
* @param key
* @return Definition factory for specified key.
* @throws DefinitionsFactoryException If an error occur while creating factory.
*/
protected DefinitionsFactory createFactory(
Object key,
ServletRequest request,
ServletContext servletContext)
throws DefinitionsFactoryException {
if (key == null) {
return getDefaultFactory();
}
// Already loaded ?
DefinitionsFactory factory = (DefinitionsFactory) loaded.get(key);
if (factory != null) { // yes, stop loading
return factory;
}
// Try to load file associated to key. If fail, stop and return default factory.
XmlDefinitionsSet lastXmlFile =
parseXmlKeyFile(servletContext, "_" + (String) key, null);
if (lastXmlFile == null) {
log.warn(
"No definition factory associated to key '"
+ key
+ "'. Use default factory instead.");
factory = getDefaultFactory();
loaded.put(key, factory);
return factory;
}
// Parse default file, and add key file.
XmlDefinitionsSet rootXmlConfig = parseXmlKeyFile(servletContext, "", null);
rootXmlConfig.extend(lastXmlFile);
rootXmlConfig.resolveInheritances();
factory = new DefinitionsFactory(rootXmlConfig);
loaded.put(key, factory);
log.info(factory);
// return last available found !
return factory;
}
/**
* Parse files associated to postix if they exist.
* For each name in filenames, append postfix before file extension,
* then try to load the corresponding file.
* If file doesn't exist, try next one. Each file description is added to
* the XmlDefinitionsSet description.
* The XmlDefinitionsSet description is created only if there is a definition file.
* Inheritance is not resolved in the returned XmlDefinitionsSet.
* If no description file can be opened, and no definiion set is provided, return null.
* @param postfix Postfix to add to each description file.
* @param xmlDefinitions Definitions set to which definitions will be added. If null, a definitions
* set is created on request.
* @return XmlDefinitionsSet The definitions set created or passed as parameter.
* @throws DefinitionsFactoryException If an error happen during file parsing.
*/
private XmlDefinitionsSet parseXmlKeyFile(
ServletContext servletContext,
String postfix,
XmlDefinitionsSet xmlDefinitions)
throws DefinitionsFactoryException {
if (postfix != null && postfix.length() == 0)
postfix = null;
String fullName = concatPostfix(filename, postfix);
return parseXmlFile(servletContext, fullName, xmlDefinitions);
}
/**
* Parse specified xml file and add definition to specified definitions set.
* This method is used to load several description files in one instances list.
* If filename exist and definition set is null, create a new set. Otherwise, return
* passed definition set (can be null).
* @param servletContext Current servlet context. Used to open file.
* @param filename Name of file to parse.
* @param xmlDefinitions Definitions set to which definitions will be added. If null, a definitions
* set is created on request.
* @return XmlDefinitionsSet The definitions set created or passed as parameter.
* @throws DefinitionsFactoryException If an error happen during file parsing.
*/
private XmlDefinitionsSet parseXmlFile(
ServletContext servletContext,
String filename,
XmlDefinitionsSet xmlDefinitions)
throws DefinitionsFactoryException {
try {
log.debug("Trying to load '" + filename + "'.");
InputStream input = servletContext.getResourceAsStream(filename);
if (input == null) {
return xmlDefinitions;
}
xmlParser = new XmlParser();
// Check if definition set already exist.
if (xmlDefinitions == null) {
xmlDefinitions = new XmlDefinitionsSet();
}
xmlParser.parse(input, xmlDefinitions);
} catch (SAXException ex) {
log.debug("Error while parsing file '" + filename + "'.", ex);
throw new DefinitionsFactoryException(
"Error while parsing file '" + filename + "'. " + ex.getMessage(),
ex);
} catch (IOException ex) {
throw new DefinitionsFactoryException(
"IO Error while parsing file '" + filename + "'. " + ex.getMessage(),
ex);
}
return xmlDefinitions;
}
/**
* Concat postfix to the name. Take care of existing filename extension.
* Transform the given name "name.ext" to have "name" + "postfix" + "ext".
* If there is no ext, return "name" + "postfix".
*/
private String concatPostfix(String name, String postfix) {
if (postfix == null) {
return name;
}
//postfix = "_" + postfix;
// Search file name extension.
// take care of Unix files starting with .
int dotIndex = name.lastIndexOf(".");
int lastNameStart = name.lastIndexOf(java.io.File.pathSeparator);
if (dotIndex < 1 || dotIndex < lastNameStart)
return name + postfix;
String ext = name.substring(dotIndex);
name = name.substring(0, dotIndex);
return name + postfix + ext;
}
}