| package org.apache.lucene.xmlparser; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.Enumeration; |
| import java.util.HashMap; |
| import java.util.Properties; |
| |
| import javax.xml.parsers.DocumentBuilder; |
| import javax.xml.parsers.DocumentBuilderFactory; |
| import javax.xml.parsers.ParserConfigurationException; |
| import javax.xml.transform.Result; |
| import javax.xml.transform.Templates; |
| import javax.xml.transform.Transformer; |
| import javax.xml.transform.TransformerConfigurationException; |
| import javax.xml.transform.TransformerException; |
| import javax.xml.transform.TransformerFactory; |
| import javax.xml.transform.dom.DOMResult; |
| import javax.xml.transform.dom.DOMSource; |
| import javax.xml.transform.stream.StreamResult; |
| |
| import org.w3c.dom.Document; |
| import org.w3c.dom.Element; |
| import org.xml.sax.SAXException; |
| |
| /** |
| * 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. |
| */ |
| /** |
| * Provides utilities for turning query form input (such as from a web page or Swing gui) into |
| * Lucene XML queries by using XSL templates. This approach offers a convenient way of externalizing |
| * and changing how user input is turned into Lucene queries. |
| * Database applications often adopt similar practices by externalizing SQL in template files that can |
| * be easily changed/optimized by a DBA. |
| * The static methods can be used on their own or by creating an instance of this class you can store and |
| * re-use compiled stylesheets for fast use (e.g. in a server environment) |
| */ |
| public class QueryTemplateManager |
| { |
| static DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance (); |
| static TransformerFactory tFactory = TransformerFactory.newInstance(); |
| |
| HashMap<String,Templates> compiledTemplatesCache=new HashMap<String,Templates>(); |
| Templates defaultCompiledTemplates=null; |
| |
| |
| public QueryTemplateManager() |
| { |
| |
| } |
| public QueryTemplateManager(InputStream xslIs) throws TransformerConfigurationException, ParserConfigurationException, SAXException, IOException |
| { |
| addDefaultQueryTemplate(xslIs); |
| } |
| public void addDefaultQueryTemplate(InputStream xslIs) throws TransformerConfigurationException, ParserConfigurationException, SAXException, IOException |
| { |
| defaultCompiledTemplates=getTemplates(xslIs); |
| } |
| public void addQueryTemplate(String name, InputStream xslIs) throws TransformerConfigurationException, ParserConfigurationException, SAXException, IOException |
| { |
| compiledTemplatesCache.put(name,getTemplates(xslIs)); |
| } |
| public String getQueryAsXmlString(Properties formProperties,String queryTemplateName) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| Templates ts= compiledTemplatesCache.get(queryTemplateName); |
| return getQueryAsXmlString(formProperties, ts); |
| } |
| |
| public Document getQueryAsDOM(Properties formProperties,String queryTemplateName) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| Templates ts= compiledTemplatesCache.get(queryTemplateName); |
| return getQueryAsDOM(formProperties, ts); |
| } |
| public String getQueryAsXmlString(Properties formProperties) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| return getQueryAsXmlString(formProperties, defaultCompiledTemplates); |
| } |
| |
| public Document getQueryAsDOM(Properties formProperties) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| return getQueryAsDOM(formProperties, defaultCompiledTemplates); |
| } |
| |
| |
| /** |
| * Fast means of constructing query using a precompiled stylesheet |
| */ |
| public static String getQueryAsXmlString(Properties formProperties, Templates template) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| ByteArrayOutputStream baos=new ByteArrayOutputStream(); |
| StreamResult result=new StreamResult(baos); |
| transformCriteria(formProperties,template,result); |
| return baos.toString(); |
| } |
| |
| /** |
| * Slow means of constructing query parsing a stylesheet from an input stream |
| */ |
| public static String getQueryAsXmlString(Properties formProperties, InputStream xslIs) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| ByteArrayOutputStream baos=new ByteArrayOutputStream(); |
| StreamResult result=new StreamResult(baos); |
| transformCriteria(formProperties,xslIs,result); |
| return baos.toString(); |
| } |
| |
| |
| /** |
| * Fast means of constructing query using a cached,precompiled stylesheet |
| */ |
| public static Document getQueryAsDOM(Properties formProperties, Templates template) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| DOMResult result=new DOMResult(); |
| transformCriteria(formProperties,template,result); |
| return (Document)result.getNode(); |
| } |
| |
| |
| /** |
| * Slow means of constructing query - parses stylesheet from input stream |
| */ |
| public static Document getQueryAsDOM(Properties formProperties, InputStream xslIs) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| DOMResult result=new DOMResult(); |
| transformCriteria(formProperties,xslIs,result); |
| return (Document)result.getNode(); |
| } |
| |
| |
| |
| |
| /** |
| * Slower transformation using an uncompiled stylesheet (suitable for development environment) |
| */ |
| public static void transformCriteria(Properties formProperties, InputStream xslIs, Result result) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| dbf.setNamespaceAware(true); |
| DocumentBuilder builder = dbf.newDocumentBuilder(); |
| org.w3c.dom.Document xslDoc = builder.parse(xslIs); |
| DOMSource ds = new DOMSource(xslDoc); |
| |
| Transformer transformer =null; |
| synchronized (tFactory) |
| { |
| transformer = tFactory.newTransformer(ds); |
| } |
| transformCriteria(formProperties,transformer,result); |
| } |
| |
| /** |
| * Fast transformation using a pre-compiled stylesheet (suitable for production environments) |
| */ |
| public static void transformCriteria(Properties formProperties, Templates template, Result result) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| transformCriteria(formProperties,template.newTransformer(),result); |
| } |
| |
| |
| |
| public static void transformCriteria(Properties formProperties, Transformer transformer, Result result) throws SAXException, IOException, ParserConfigurationException, TransformerException |
| { |
| dbf.setNamespaceAware(true); |
| |
| //Create an XML document representing the search index document. |
| DocumentBuilder db = dbf.newDocumentBuilder (); |
| org.w3c.dom.Document doc = db.newDocument (); |
| Element root = doc.createElement ("Document"); |
| doc.appendChild (root); |
| |
| Enumeration keysEnum = formProperties.keys(); |
| while(keysEnum.hasMoreElements()) |
| { |
| String propName=(String) keysEnum.nextElement(); |
| String value=formProperties.getProperty(propName); |
| if((value!=null)&&(value.length()>0)) |
| { |
| DOMUtils.insertChild(root,propName,value); |
| } |
| } |
| //Use XSLT to to transform into an XML query string using the queryTemplate |
| DOMSource xml=new DOMSource(doc); |
| transformer.transform(xml,result); |
| } |
| |
| /** |
| * Parses a query stylesheet for repeated use |
| */ |
| public static Templates getTemplates(InputStream xslIs) throws ParserConfigurationException, SAXException, IOException, TransformerConfigurationException |
| { |
| dbf.setNamespaceAware(true); |
| DocumentBuilder builder = dbf.newDocumentBuilder(); |
| org.w3c.dom.Document xslDoc = builder.parse(xslIs); |
| DOMSource ds = new DOMSource(xslDoc); |
| return tFactory.newTemplates(ds); |
| } |
| } |