01: /*
02: * Copyright 1999-2004 The Apache Software Foundation
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: package org.apache.commons.jxpath;
17:
18: import java.net.URL;
19:
20: import javax.xml.transform.Source;
21: import javax.xml.transform.Transformer;
22: import javax.xml.transform.TransformerFactory;
23: import javax.xml.transform.dom.DOMResult;
24:
25: import org.apache.commons.jxpath.xml.DocumentContainer;
26: import org.w3c.dom.Document;
27:
28: /**
29: * An XML document container reads and parses XML only when it is
30: * accessed. JXPath traverses Containers transparently -
31: * you use the same paths to access objects in containers as you
32: * do to access those objects directly. You can create
33: * XMLDocumentContainers for various XML documents that may or
34: * may not be accessed by XPaths. If they are, they will be automatically
35: * read, parsed and traversed. If they are not - they won't be
36: * read at all.
37: *
38: * @deprecated 1.1 Please use org.apache.commons.jxpath.xml.DocumentContainer
39: *
40: * @author Dmitri Plotnikov
41: * @version $Revision: 1.11 $ $Date: 2004/02/29 14:17:42 $
42: */
43: public class XMLDocumentContainer implements Container {
44:
45: private DocumentContainer delegate;
46: private Object document;
47: private URL xmlURL;
48: private Source source;
49: private String parser;
50:
51: /**
52: * @param URL is a URL for an XML file. Use getClass().getResource
53: * (resourceName) to load XML from a resource file.
54: */
55: public XMLDocumentContainer(URL xmlURL) {
56: delegate = new DocumentContainer(xmlURL);
57: }
58:
59: public XMLDocumentContainer(Source source) {
60: this .source = source;
61: if (source == null) {
62: throw new RuntimeException("Source is null");
63: }
64: }
65:
66: /**
67: * Reads XML, caches it internally and returns the Document.
68: */
69: public Object getValue() {
70: if (document == null) {
71: try {
72: if (source != null) {
73: DOMResult result = new DOMResult();
74: Transformer trans = TransformerFactory
75: .newInstance().newTransformer();
76: trans.transform(source, result);
77: document = (Document) result.getNode();
78: } else {
79: document = delegate.getValue();
80: }
81: } catch (Exception ex) {
82: throw new JXPathException("Cannot read XML from: "
83: + (xmlURL != null ? xmlURL.toString()
84: : (source != null ? source
85: .getSystemId()
86: : "<<undefined source>>")), ex);
87: }
88: }
89: return document;
90: }
91:
92: /**
93: * Throws an UnsupportedOperationException
94: */
95: public void setValue(Object value) {
96: throw new UnsupportedOperationException();
97: }
98: }
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