01: /*
02: * Copyright 2005 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
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
39: TransformerObjectSupport implements PayloadEndpoint {
40:
41: /**
42: * Invokes the provided <code>ContentHandler</code> on the given request. After parsing has been done, the provided
43: * response is returned.
44: *
45: * @see #createContentHandler()
46: * @see #getResponse(org.xml.sax.ContentHandler)
47: */
48: public final Source invoke(Source request) throws Exception {
49: ContentHandler contentHandler = null;
50: if (request != null) {
51: contentHandler = createContentHandler();
52: SAXResult result = new SAXResult(contentHandler);
53: transform(request, result);
54: }
55: return getResponse(contentHandler);
56: }
57:
58: /**
59: * Returns the SAX <code>ContentHandler</code> used to parse the incoming request payload. A new instance should be
60: * created for each call, because of thread-safety. The content handler can be used to hold request-specific state.
61: * <p/>
62: * If an incoming message does not contain a payload, this method will not be invoked.
63: *
64: * @return a SAX content handler to be used for parsing
65: */
66: protected abstract ContentHandler createContentHandler()
67: throws Exception;
68:
69: /**
70: * Returns the response to be given, if any. This method is called after the request payload has been parsed using
71: * the SAX <code>ContentHandler</code>. The passed <code>ContentHandler</code> is created by {@link
72: * #createContentHandler()}: it can be used to hold request-specific state.
73: * <p/>
74: * If an incoming message does not contain a payload, this method will be invoked with <code>null</code> as content
75: * handler.
76: *
77: * @param contentHandler the content handler used to parse the request
78: */
79: protected abstract Source getResponse(ContentHandler contentHandler)
80: throws Exception;
81: }
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