/*
* 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.cocoon.components.source.impl;
import java.io.IOException;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.parameters.ParameterException;
import org.apache.avalon.framework.parameters.Parameterizable;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.components.source.SourceInspector;
import org.apache.cocoon.components.source.helpers.SourceProperty;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceException;
import org.apache.excalibur.source.SourceValidity;
import org.apache.excalibur.source.impl.validity.NOPValidity;
import org.apache.excalibur.xml.dom.DOMParser;
import org.apache.excalibur.xml.xpath.XPathProcessor;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* This source inspector inspects XML files with a xpath expression.
*
* @version CVS $Id: XPathSourceInspector.java,v 1.8 2004/03/27 21:49:09 unico Exp $
*/
public class XPathSourceInspector extends AbstractLogEnabled
implements SourceInspector, Serviceable, Parameterizable, ThreadSafe {
/**
* The default namespace uri of the property exposed by this SourceInspector.
* <p>
* The value is <code>http://apache.org/cocoon/inspector/xpath/1.0</code>.
* </p>
*/
public static final String DEFAULT_PROPERTY_NS = "http://apache.org/cocoon/inspector/xpath/1.0";
/**
* The default property name exposed by this SourceInspector.
* <p>
* The value is <code>result</code> .
* </p>
*/
public static final String DEFAULT_PROPERTY_NAME = "result";
private String m_namespace;
private String m_propertyname;
private String m_extension;
private String m_xpath;
private ServiceManager manager = null;
public XPathSourceInspector() {
}
public void service(ServiceManager manager) {
this.manager = manager;
}
public void parameterize(Parameters params) throws ParameterException {
this.m_namespace = params.getParameter("namespace", DEFAULT_PROPERTY_NS);
this.m_propertyname = params.getParameter("name", DEFAULT_PROPERTY_NAME);
this.m_extension = params.getParameter("extension", ".xml");
this.m_xpath = params.getParameter("xpath", "/*");
}
public SourceProperty getSourceProperty(Source source, String namespace, String name)
throws SourceException {
if ((namespace.equals(m_namespace)) &&
(name.equals(m_propertyname)) &&
(source.getURI().endsWith(m_extension))) {
DOMParser parser = null;
Document doc = null;
try {
parser = (DOMParser) manager.lookup(DOMParser.ROLE);
doc = parser.parseDocument(new InputSource(source.getInputStream()));
} catch (SAXException se) {
this.getLogger().error(source.getURI() + " is not a valid XML file");
} catch (IOException ioe) {
this.getLogger().error("Could not read file", ioe);
} catch (ServiceException ce) {
this.getLogger().error("Missing service dependency: DOMParser", ce);
} finally {
if (parser != null) {
this.manager.release(parser);
}
}
if (doc != null) {
XPathProcessor processor = null;
try {
processor = (XPathProcessor)manager.lookup(XPathProcessor.ROLE);
NodeList nodelist = processor.selectNodeList(doc.getDocumentElement(), m_xpath);
SourceProperty property = new SourceProperty(m_namespace, m_propertyname);
property.setValue(nodelist);
return property;
} catch (ServiceException se) {
this.getLogger().error("Could not retrieve component", se);
} finally {
if (processor != null) {
this.manager.release(processor);
}
}
}
}
return null;
}
public SourceProperty[] getSourceProperties(Source source) throws SourceException {
SourceProperty property = getSourceProperty(source, this.m_namespace, this.m_propertyname);
if (property!=null)
return new SourceProperty[]{property};
return null;
}
public boolean handlesProperty(String namespace, String name) {
return this.m_namespace.equals(namespace) && this.m_propertyname.equals(name);
}
/**
* Returns NOPValidity
*/
public SourceValidity getValidity(Source source) {
return NOPValidity.SHARED_INSTANCE;
}
}