/*
* Copyright 2005 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.
*
* $Header:$
*/
package org.apache.beehive.netui.pageflow.internal;
import org.apache.beehive.netui.core.urltemplates.URLTemplate;
import org.apache.beehive.netui.core.urltemplates.URLTemplates;
import org.apache.beehive.netui.core.urltemplates.URLTemplatesFactory;
import org.apache.beehive.netui.util.logging.Logger;
import org.apache.beehive.netui.util.xml.DomUtils;
import org.apache.beehive.netui.util.xml.XmlInputStreamResolver;
import java.io.InputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import javax.servlet.ServletContext;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXParseException;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
/**
* Methods for configuring and retrieving the URLTemplate object.
*/
public class DefaultURLTemplatesFactory extends URLTemplatesFactory
{
private static final Logger _log = Logger.getInstance( DefaultURLTemplatesFactory.class );
// Constants for schema elements
private static final String KEY = "key";
private static final String NAME = "name";
private static final String TEMPLATE_NAME = "template-name";
private static final String URL_TEMPLATE = "url-template";
private static final String URL_TEMPLATE_REF = "url-template-ref";
private static final String URL_TEMPLATE_REF_GROUP = "url-template-ref-group";
private static final String VALUE = "value";
private static final String CONFIG_SCHEMA = "org/apache/beehive/netui/core/urltemplates/schema/url-template-config.xsd";
private static final XmlInputStreamResolver SCHEMA_RESOLVER = new XmlInputStreamResolver() {
public String getResourcePath() {
return CONFIG_SCHEMA;
}
public InputStream getInputStream() {
return DefaultURLTemplatesFactory.class.getClassLoader().getResourceAsStream(getResourcePath());
}
};
// The actual URL templates and template ref groups
private URLTemplates _urlTemplates;
/**
* Returns URL template given the name of the template.
*
* @param name name of the template
* @return template
*/
public URLTemplate getURLTemplate( String name )
{
assert _urlTemplates != null : "The template config file has not been loaded.";
if ( _urlTemplates == null )
{
return null;
}
return _urlTemplates.getTemplate( name );
}
/**
* Returns URL template name of the given type (by key) from the
* desired reference group.
*
* @param refGroupName name of a group of templates from the config file.
* @param key type of the template
* @return template name
*/
public String getTemplateNameByRef( String refGroupName, String key )
{
assert _urlTemplates != null : "The template config file has not been loaded.";
if ( _urlTemplates == null )
{
return null;
}
String ref = _urlTemplates.getTemplateNameByRef( refGroupName, key );
if ( ref == null )
{
// If the template is a secure template, look for the secure default
// before resolving to the default
if ( key.equals( URLTemplatesFactory.SECURE_RENDER_TEMPLATE ) ||
key.equals( URLTemplatesFactory.SECURE_ACTION_TEMPLATE ) ||
key.equals( URLTemplatesFactory.SECURE_RESOURCE_TEMPLATE ) )
{
ref = _urlTemplates.getTemplateNameByRef( refGroupName, URLTemplatesFactory.SECURE_DEFAULT_TEMPLATE );
}
}
return ref;
}
/**
* Initialization method that parses the URL template config file to
* get the URL templates and template reference groups.
*
* @param servletContext the current ServletContext.
*/
public void load( ServletContext servletContext )
{
_urlTemplates = new URLTemplates();
InputStream xmlInputStream = null;
InputStream xsdInputStream = null;
try
{
xmlInputStream = servletContext.getResourceAsStream( _configFilePath );
if ( xmlInputStream != null ) {
/* load the XSD input stream */
xsdInputStream = SCHEMA_RESOLVER.getInputStream();
final String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema";
final String JAXP_SCHEMA_LANGUAGE = "http://java.sun.com/xml/jaxp/properties/schemaLanguage";
final String JAXP_SCHEMA_SOURCE = "http://java.sun.com/xml/jaxp/properties/schemaSource";
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setValidating(true);
dbf.setNamespaceAware(true);
dbf.setAttribute(JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA);
dbf.setAttribute(JAXP_SCHEMA_SOURCE, xsdInputStream);
DocumentBuilder db = dbf.newDocumentBuilder();
/* add an ErrorHandler that just logs validation problems */
db.setErrorHandler(new ErrorHandler() {
public void warning(SAXParseException exception) {
_log.info("Validation warning validating config file \"" + _configFilePath + "\" against XML Schema \"" + SCHEMA_RESOLVER.getResourcePath());
}
public void error(SAXParseException exception) {
_log.error("Validation errors occurred parsing the config file \"" + _configFilePath + "\". Cause: " + exception, exception);
}
public void fatalError(SAXParseException exception) {
_log.error("Validation errors occurred parsing the config file \"" + _configFilePath + "\". Cause: " + exception, exception);
}
});
db.setEntityResolver(new EntityResolver() {
public InputSource resolveEntity(String publicId, String systemId) {
if(systemId.endsWith("/url-template-config.xsd")) {
InputStream inputStream = DefaultURLTemplatesFactory.class.getClassLoader().getResourceAsStream(CONFIG_SCHEMA);
return new InputSource(inputStream);
}
else return null;
}
});
Document document = db.parse(xmlInputStream);
Element root = document.getDocumentElement();
loadTemplates( root );
loadTemplateRefGroups( root );
}
else
{
if ( _log.isInfoEnabled() )
_log.info( "Running without URL template descriptor, " + _configFilePath );
}
}
catch ( ParserConfigurationException pce )
{
_log.error( "Problem loading URL template descriptor file " + _configFilePath, pce );
}
catch ( SAXException se )
{
_log.error( "Problem parsing URL template descriptor in " + _configFilePath, se );
}
catch ( IOException ioe )
{
_log.error( "Problem reading URL template descriptor file " + _configFilePath, ioe );
}
finally
{
// Close the streams
try { if ( xmlInputStream != null ) xmlInputStream.close(); } catch ( Exception ignore ) {}
try { if ( xsdInputStream != null ) xsdInputStream.close(); } catch( IOException ignore ) {}
}
}
/**
* Loads the templates from a URL template config document.
*
* @param parent
*/
private void loadTemplates( Element parent )
{
// Load templates
List templates = DomUtils.getChildElementsByName( parent, URL_TEMPLATE );
for ( int i = 0; i < templates.size(); i++ )
{
Element template = ( Element ) templates.get( i );
String name = getElementText( template, NAME );
if ( name == null )
{
_log.error( "Malformed URL template descriptor in " + _configFilePath
+ ". The url-template name is missing." );
continue;
}
String value = getElementText( template, VALUE );
if ( value == null )
{
_log.error( "Malformed URL template descriptor in " + _configFilePath
+ ". The url-template value is missing for template " + name );
continue;
}
if ( _log.isDebugEnabled() )
{
_log.debug( "[URLTemplate] " + name + " = " + value );
}
URLTemplate urlTemplate = new URLTemplate( value );
if ( urlTemplate.verify( _knownTokens, _requiredTokens ) )
{
_urlTemplates.addTemplate( name, urlTemplate );
}
}
}
/**
* Loads the template reference groups from a URL template config document.
*
* @param parent
*/
private void loadTemplateRefGroups( Element parent )
{
// Load template refs
List templateRefGroups = DomUtils.getChildElementsByName( parent, URL_TEMPLATE_REF_GROUP );;
for ( int i = 0; i < templateRefGroups.size(); i++ )
{
Element refGroupElement = ( Element ) templateRefGroups.get( i );
String refGroupName = getElementText( refGroupElement, NAME );
if ( refGroupName == null )
{
_log.error( "Malformed URL template descriptor in " + _configFilePath
+ ". The url-template-ref-group name is missing." );
continue;
}
HashMap refGroup = new HashMap();
List templateRefs = DomUtils.getChildElementsByName( refGroupElement, URL_TEMPLATE_REF );;
for ( int j = 0; j < templateRefs.size(); j++ )
{
Element templateRefElement = ( Element ) templateRefs.get( j );
String key = getElementText( templateRefElement, KEY );
if ( key == null )
{
_log.error( "Malformed URL template descriptor in " + _configFilePath
+ ". The url-template-ref key is missing in url-template-ref-group " + refGroupName );
continue;
}
String name = getElementText( templateRefElement, TEMPLATE_NAME );
if ( name != null )
{
refGroup.put( key, name );
if ( _log.isDebugEnabled() )
{
_log.debug( "[" + refGroupName + " URLTemplate] " + key + " = " + name );
}
}
else
{
_log.error( "Malformed URL template descriptor in " + _configFilePath
+ ". The url-template-ref template-name is missing in url-template-ref-group " + refGroupName );
}
}
if ( refGroup.size() != 0 )
{
_urlTemplates.addTemplateRefGroup( refGroupName, refGroup );
}
}
}
private String getElementText( Element parent, String elementName )
{
Element child = DomUtils.getChildElementByName( parent, elementName );
if ( child != null )
{
String text = DomUtils.getElementText( child );
if ( text != null )
{
text = text.trim();
return text.length() == 0 ? null : text;
}
}
return null;
}
}