1 /* 2 * Copyright 2005 the original author or authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.springframework.ws.server.endpoint; 18 19 import javax.xml.transform.Source; 20 import javax.xml.transform.sax.SAXResult; 21 22 import org.springframework.xml.transform.TransformerObjectSupport; 23 import org.xml.sax.ContentHandler; 24 25 /** 26 * Abstract base class for endpoints that handle the message payload with a SAX <code>ContentHandler</code>. Allows 27 * subclasses to create a response by returning a <code>Source</code>. 28 * <p/> 29 * Implementations of this class should create a new handler for each call of <code>createContentHandler</code>, because 30 * of thread safety. The handlers is later passed on to <code>createResponse</code>, so it can be used for holding 31 * request-specific state. 32 * 33 * @author Arjen Poutsma 34 * @see #createContentHandler() 35 * @see #getResponse(org.xml.sax.ContentHandler) 36 * @since 1.0.0 37 */ 38 public abstract class AbstractSaxPayloadEndpoint extends TransformerObjectSupport implements PayloadEndpoint { 39 40 /** 41 * Invokes the provided <code>ContentHandler</code> on the given request. After parsing has been done, the provided 42 * response is returned. 43 * 44 * @see #createContentHandler() 45 * @see #getResponse(org.xml.sax.ContentHandler) 46 */ 47 public final Source invoke(Source request) throws Exception { 48 ContentHandler contentHandler = null; 49 if (request != null) { 50 contentHandler = createContentHandler(); 51 SAXResult result = new SAXResult(contentHandler); 52 transform(request, result); 53 } 54 return getResponse(contentHandler); 55 } 56 57 /** 58 * Returns the SAX <code>ContentHandler</code> used to parse the incoming request payload. A new instance should be 59 * created for each call, because of thread-safety. The content handler can be used to hold request-specific state. 60 * <p/> 61 * If an incoming message does not contain a payload, this method will not be invoked. 62 * 63 * @return a SAX content handler to be used for parsing 64 */ 65 protected abstract ContentHandler createContentHandler() throws Exception; 66 67 /** 68 * Returns the response to be given, if any. This method is called after the request payload has been parsed using 69 * the SAX <code>ContentHandler</code>. The passed <code>ContentHandler</code> is created by {@link 70 * #createContentHandler()}: it can be used to hold request-specific state. 71 * <p/> 72 * If an incoming message does not contain a payload, this method will be invoked with <code>null</code> as content 73 * handler. 74 * 75 * @param contentHandler the content handler used to parse the request 76 */ 77 protected abstract Source getResponse(ContentHandler contentHandler) throws Exception; 78 }