src/main/java/freemarker/ext/dom/JaxenXPathSupport.java - freemarker - Git at Google

 /*
  * 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 freemarker.ext.dom;

 import java.io.IOException;
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;

 import org.jaxen.BaseXPath;
 import org.jaxen.Function;
 import org.jaxen.FunctionCallException;
 import org.jaxen.FunctionContext;
 import org.jaxen.JaxenException;
 import org.jaxen.NamespaceContext;
 import org.jaxen.Navigator;
 import org.jaxen.UnresolvableException;
 import org.jaxen.VariableContext;
 import org.jaxen.XPathFunctionContext;
 import org.jaxen.dom.DocumentNavigator;
 import org.w3c.dom.Document;
 import org.xml.sax.EntityResolver;
 import org.xml.sax.InputSource;
 import org.xml.sax.SAXException;

 import freemarker.core.CustomAttribute;
 import freemarker.core.Environment;
 import freemarker.template.ObjectWrapper;
 import freemarker.template.Template;
 import freemarker.template.TemplateBooleanModel;
 import freemarker.template.TemplateDateModel;
 import freemarker.template.TemplateException;
 import freemarker.template.TemplateModel;
 import freemarker.template.TemplateModelException;
 import freemarker.template.TemplateNumberModel;
 import freemarker.template.TemplateScalarModel;
 import freemarker.template.utility.UndeclaredThrowableException;


 /**
  */
 class JaxenXPathSupport implements XPathSupport {

     private static final CustomAttribute XPATH_CACHE_ATTR =
         new CustomAttribute(CustomAttribute.SCOPE_TEMPLATE) {
             @Override
             protected Object create() {
                 return new HashMap<String, BaseXPath>();
             }
         };

         // [2.4] Can't we just use Collections.emptyList()?
     private final static ArrayList EMPTY_ARRAYLIST = new ArrayList();

     @Override
     public TemplateModel executeQuery(Object context, String xpathQuery) throws TemplateModelException {
         try {
             BaseXPath xpath;
             Map<String, BaseXPath> xpathCache = (Map<String, BaseXPath>) XPATH_CACHE_ATTR.get();
             synchronized (xpathCache) {
                 xpath = xpathCache.get(xpathQuery);
                 if (xpath == null) {
                     xpath = new BaseXPath(xpathQuery, FM_DOM_NAVIGATOR);
                     xpath.setNamespaceContext(customNamespaceContext);
                     xpath.setFunctionContext(FM_FUNCTION_CONTEXT);
                     xpath.setVariableContext(FM_VARIABLE_CONTEXT);
                     xpathCache.put(xpathQuery, xpath);
                 }
             }
             List result = xpath.selectNodes(context != null ? context : EMPTY_ARRAYLIST);
             if (result.size() == 1) {
                 // [2.4] Use the proper object wrapper (argument in 2.4)
                 return ObjectWrapper.DEFAULT_WRAPPER.wrap(result.get(0));
             }
             NodeListModel nlm = new NodeListModel(result, null);
             nlm.xpathSupport = this;
             return nlm;
         } catch (UndeclaredThrowableException e) {
             Throwable t  = e.getUndeclaredThrowable();
             if (t instanceof TemplateModelException) {
                 throw (TemplateModelException) t;
             }
             throw e;
         } catch (JaxenException je) {
             throw new TemplateModelException(je);
         }
     }

     static private final NamespaceContext customNamespaceContext = new NamespaceContext() {

         @Override
         public String translateNamespacePrefixToUri(String prefix) {
             if (prefix.equals(Template.DEFAULT_NAMESPACE_PREFIX)) {
                 return Environment.getCurrentEnvironment().getDefaultNS();
             }
             return Environment.getCurrentEnvironment().getNamespaceForPrefix(prefix);
         }
     };

     private static final VariableContext FM_VARIABLE_CONTEXT = new VariableContext() {
         @Override
         public Object getVariableValue(String namespaceURI, String prefix, String localName)
         throws UnresolvableException {
             try {
                 TemplateModel model = Environment.getCurrentEnvironment().getVariable(localName);
                 if (model == null) {
                     throw new UnresolvableException("Variable \"" + localName + "\" not found.");
                 }
                 if (model instanceof TemplateScalarModel) {
                     return ((TemplateScalarModel) model).getAsString();
                 }
                 if (model instanceof TemplateNumberModel) {
                     return ((TemplateNumberModel) model).getAsNumber();
                 }
                 if (model instanceof TemplateDateModel) {
                     return ((TemplateDateModel) model).getAsDate();
                 }
                 if (model instanceof TemplateBooleanModel) {
                     return Boolean.valueOf(((TemplateBooleanModel) model).getAsBoolean());
                 }
             } catch (TemplateModelException e) {
                 throw new UndeclaredThrowableException(e);
             }
             throw new UnresolvableException(
                     "Variable \"" + localName + "\" exists, but it's not a string, number, date, or boolean");
         }
     };

     private static final FunctionContext FM_FUNCTION_CONTEXT = new XPathFunctionContext() {
         @Override
         public Function getFunction(String namespaceURI, String prefix, String localName)
         throws UnresolvableException {
             try {
                 return super.getFunction(namespaceURI, prefix, localName);
             } catch (UnresolvableException e) {
                 return super.getFunction(null, null, localName);
             }
         }
     };

     /**
      * Stores the the template parsed as {@link Document} in the template itself.
      */
     private static final CustomAttribute FM_DOM_NAVIAGOTOR_CACHED_DOM
             = new CustomAttribute(CustomAttribute.SCOPE_TEMPLATE);

     private static final Navigator FM_DOM_NAVIGATOR = new DocumentNavigator() {
         @Override
         public Object getDocument(String uri) throws FunctionCallException {
             try {
                 Template raw = getTemplate(uri);
                 Document doc = (Document) FM_DOM_NAVIAGOTOR_CACHED_DOM.get(raw);
                 if (doc == null) {
                     DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                     factory.setNamespaceAware(true);
                     DocumentBuilder builder = factory.newDocumentBuilder();
                     FmEntityResolver er = new FmEntityResolver();
                     builder.setEntityResolver(er);
                     doc = builder.parse(createInputSource(null, raw));
                     // If the entity resolver got called 0 times, the document
                     // is standalone, so we can safely cache it
                     if (er.getCallCount() == 0) {
                         FM_DOM_NAVIAGOTOR_CACHED_DOM.set(doc, raw);
                     }
                 }
                 return doc;
             } catch (Exception e) {
                 throw new FunctionCallException("Failed to parse document for URI: " + uri, e);
             }
         }
     };

     static Template getTemplate(String systemId) throws IOException {
         Environment env = Environment.getCurrentEnvironment();
         String encoding = env.getTemplate().getEncoding();
         if (encoding == null) {
             encoding = env.getConfiguration().getEncoding(env.getLocale());
         }
         String templatePath = env.getTemplate().getName();
         int lastSlash = templatePath.lastIndexOf('/');
         templatePath = lastSlash == -1 ? "" : templatePath.substring(0, lastSlash + 1);
         systemId = env.toFullTemplateName(templatePath, systemId);
         Template raw = env.getConfiguration().getTemplate(systemId, env.getLocale(), encoding, false);
         return raw;
     }

     private static InputSource createInputSource(String publicId, Template raw) throws IOException, SAXException {
         StringWriter sw = new StringWriter();
         try {
             raw.process(Collections.EMPTY_MAP, sw);
         } catch (TemplateException e) {
             throw new SAXException(e);
         }
         InputSource is = new InputSource();
         is.setPublicId(publicId);
         is.setSystemId(raw.getName());
         is.setCharacterStream(new StringReader(sw.toString()));
         return is;
     }

     private static class FmEntityResolver implements EntityResolver {
         private int callCount = 0;

         @Override
         public InputSource resolveEntity(String publicId, String systemId)
         throws SAXException, IOException {
             ++callCount;
             return createInputSource(publicId, getTemplate(systemId));
         }

         int getCallCount() {
             return callCount;
         }
     };
 }
	/*
	* 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 freemarker.ext.dom;

	import java.io.IOException;
	import java.io.StringReader;
	import java.io.StringWriter;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;

	import javax.xml.parsers.DocumentBuilder;
	import javax.xml.parsers.DocumentBuilderFactory;

	import org.jaxen.BaseXPath;
	import org.jaxen.Function;
	import org.jaxen.FunctionCallException;
	import org.jaxen.FunctionContext;
	import org.jaxen.JaxenException;
	import org.jaxen.NamespaceContext;
	import org.jaxen.Navigator;
	import org.jaxen.UnresolvableException;
	import org.jaxen.VariableContext;
	import org.jaxen.XPathFunctionContext;
	import org.jaxen.dom.DocumentNavigator;
	import org.w3c.dom.Document;
	import org.xml.sax.EntityResolver;
	import org.xml.sax.InputSource;
	import org.xml.sax.SAXException;

	import freemarker.core.CustomAttribute;
	import freemarker.core.Environment;
	import freemarker.template.ObjectWrapper;
	import freemarker.template.Template;
	import freemarker.template.TemplateBooleanModel;
	import freemarker.template.TemplateDateModel;
	import freemarker.template.TemplateException;
	import freemarker.template.TemplateModel;
	import freemarker.template.TemplateModelException;
	import freemarker.template.TemplateNumberModel;
	import freemarker.template.TemplateScalarModel;
	import freemarker.template.utility.UndeclaredThrowableException;


	/**
	*/
	class JaxenXPathSupport implements XPathSupport {

	private static final CustomAttribute XPATH_CACHE_ATTR =
	new CustomAttribute(CustomAttribute.SCOPE_TEMPLATE) {
	@Override
	protected Object create() {
	return new HashMap<String, BaseXPath>();
	}
	};

	// [2.4] Can't we just use Collections.emptyList()?
	private final static ArrayList EMPTY_ARRAYLIST = new ArrayList();

	@Override
	public TemplateModel executeQuery(Object context, String xpathQuery) throws TemplateModelException {
	try {
	BaseXPath xpath;
	Map<String, BaseXPath> xpathCache = (Map<String, BaseXPath>) XPATH_CACHE_ATTR.get();
	synchronized (xpathCache) {
	xpath = xpathCache.get(xpathQuery);
	if (xpath == null) {
	xpath = new BaseXPath(xpathQuery, FM_DOM_NAVIGATOR);
	xpath.setNamespaceContext(customNamespaceContext);
	xpath.setFunctionContext(FM_FUNCTION_CONTEXT);
	xpath.setVariableContext(FM_VARIABLE_CONTEXT);
	xpathCache.put(xpathQuery, xpath);
	}
	}
	List result = xpath.selectNodes(context != null ? context : EMPTY_ARRAYLIST);
	if (result.size() == 1) {
	// [2.4] Use the proper object wrapper (argument in 2.4)
	return ObjectWrapper.DEFAULT_WRAPPER.wrap(result.get(0));
	}
	NodeListModel nlm = new NodeListModel(result, null);
	nlm.xpathSupport = this;
	return nlm;
	} catch (UndeclaredThrowableException e) {
	Throwable t = e.getUndeclaredThrowable();
	if (t instanceof TemplateModelException) {
	throw (TemplateModelException) t;
	}
	throw e;
	} catch (JaxenException je) {
	throw new TemplateModelException(je);
	}
	}

	static private final NamespaceContext customNamespaceContext = new NamespaceContext() {

	@Override
	public String translateNamespacePrefixToUri(String prefix) {
	if (prefix.equals(Template.DEFAULT_NAMESPACE_PREFIX)) {
	return Environment.getCurrentEnvironment().getDefaultNS();
	}
	return Environment.getCurrentEnvironment().getNamespaceForPrefix(prefix);
	}
	};

	private static final VariableContext FM_VARIABLE_CONTEXT = new VariableContext() {
	@Override
	public Object getVariableValue(String namespaceURI, String prefix, String localName)
	throws UnresolvableException {
	try {
	TemplateModel model = Environment.getCurrentEnvironment().getVariable(localName);
	if (model == null) {
	throw new UnresolvableException("Variable \"" + localName + "\" not found.");
	}
	if (model instanceof TemplateScalarModel) {
	return ((TemplateScalarModel) model).getAsString();
	}
	if (model instanceof TemplateNumberModel) {
	return ((TemplateNumberModel) model).getAsNumber();
	}
	if (model instanceof TemplateDateModel) {
	return ((TemplateDateModel) model).getAsDate();
	}
	if (model instanceof TemplateBooleanModel) {
	return Boolean.valueOf(((TemplateBooleanModel) model).getAsBoolean());
	}
	} catch (TemplateModelException e) {
	throw new UndeclaredThrowableException(e);
	}
	throw new UnresolvableException(
	"Variable \"" + localName + "\" exists, but it's not a string, number, date, or boolean");
	}
	};

	private static final FunctionContext FM_FUNCTION_CONTEXT = new XPathFunctionContext() {
	@Override
	public Function getFunction(String namespaceURI, String prefix, String localName)
	throws UnresolvableException {
	try {
	return super.getFunction(namespaceURI, prefix, localName);
	} catch (UnresolvableException e) {
	return super.getFunction(null, null, localName);
	}
	}
	};

	/**
	* Stores the the template parsed as {@link Document} in the template itself.
	*/
	private static final CustomAttribute FM_DOM_NAVIAGOTOR_CACHED_DOM
	= new CustomAttribute(CustomAttribute.SCOPE_TEMPLATE);

	private static final Navigator FM_DOM_NAVIGATOR = new DocumentNavigator() {
	@Override
	public Object getDocument(String uri) throws FunctionCallException {
	try {
	Template raw = getTemplate(uri);
	Document doc = (Document) FM_DOM_NAVIAGOTOR_CACHED_DOM.get(raw);
	if (doc == null) {
	DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
	factory.setNamespaceAware(true);
	DocumentBuilder builder = factory.newDocumentBuilder();
	FmEntityResolver er = new FmEntityResolver();
	builder.setEntityResolver(er);
	doc = builder.parse(createInputSource(null, raw));
	// If the entity resolver got called 0 times, the document
	// is standalone, so we can safely cache it
	if (er.getCallCount() == 0) {
	FM_DOM_NAVIAGOTOR_CACHED_DOM.set(doc, raw);
	}
	}
	return doc;
	} catch (Exception e) {
	throw new FunctionCallException("Failed to parse document for URI: " + uri, e);
	}
	}
	};

	static Template getTemplate(String systemId) throws IOException {
	Environment env = Environment.getCurrentEnvironment();
	String encoding = env.getTemplate().getEncoding();
	if (encoding == null) {
	encoding = env.getConfiguration().getEncoding(env.getLocale());
	}
	String templatePath = env.getTemplate().getName();
	int lastSlash = templatePath.lastIndexOf('/');
	templatePath = lastSlash == -1 ? "" : templatePath.substring(0, lastSlash + 1);
	systemId = env.toFullTemplateName(templatePath, systemId);
	Template raw = env.getConfiguration().getTemplate(systemId, env.getLocale(), encoding, false);
	return raw;
	}

	private static InputSource createInputSource(String publicId, Template raw) throws IOException, SAXException {
	StringWriter sw = new StringWriter();
	try {
	raw.process(Collections.EMPTY_MAP, sw);
	} catch (TemplateException e) {
	throw new SAXException(e);
	}
	InputSource is = new InputSource();
	is.setPublicId(publicId);
	is.setSystemId(raw.getName());
	is.setCharacterStream(new StringReader(sw.toString()));
	return is;
	}

	private static class FmEntityResolver implements EntityResolver {
	private int callCount = 0;

	@Override
	public InputSource resolveEntity(String publicId, String systemId)
	throws SAXException, IOException {
	++callCount;
	return createInputSource(publicId, getTemplate(systemId));
	}

	int getCallCount() {
	return callCount;
	}
	};
	}