1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 /*
6 * Copyright 2004,2005 The Apache Software Foundation.
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21 package com.sun.org.apache.xerces.internal.util;
22
23 import java.io.InputStream;
24 import java.io.IOException;
25 import java.io.Reader;
26
27 import com.sun.org.apache.xerces.internal.impl.ExternalSubsetResolver;
28 import com.sun.org.apache.xerces.internal.impl.XMLEntityDescription;
29 import com.sun.org.apache.xerces.internal.xni.XMLResourceIdentifier;
30 import com.sun.org.apache.xerces.internal.xni.XNIException;
31 import com.sun.org.apache.xerces.internal.xni.grammars.XMLDTDDescription;
32 import com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource;
33
34 import org.xml.sax.ext.EntityResolver2;
35 import org.xml.sax.InputSource;
36 import org.xml.sax.SAXException;
37
38 /**
39 * <p>This class wraps a SAX entity resolver (EntityResolver2) in an XNI entity resolver.</p>
40 *
41 * @author Michael Glavassevich, IBM
42 *
43 */
44 public class EntityResolver2Wrapper
45 implements ExternalSubsetResolver {
46
47 //
48 // Data
49 //
50
51 /** An instance of SAX2 Extensions 1.1's EntityResolver2. */
52 protected EntityResolver2 fEntityResolver;
53
54 //
55 // Constructors
56 //
57
58 /** Default constructor. */
59 public EntityResolver2Wrapper() {}
60
61 /**
62 * <p>Creates a new instance wrapping the given SAX entity resolver.</p>
63 *
64 * @param entityResolver the SAX entity resolver to wrap
65 */
66 public EntityResolver2Wrapper(EntityResolver2 entityResolver) {
67 setEntityResolver(entityResolver);
68 } // <init>(EntityResolver2)
69
70 //
71 // Public methods
72 //
73
74 /**
75 * <p>Sets the SAX entity resolver wrapped by this object.</p>
76 *
77 * @param entityResolver the SAX entity resolver to wrap
78 */
79 public void setEntityResolver(EntityResolver2 entityResolver) {
80 fEntityResolver = entityResolver;
81 } // setEntityResolver(EntityResolver2)
82
83 /**
84 * <p>Returns the SAX entity resolver wrapped by this object.</p>
85 *
86 * @return the SAX entity resolver wrapped by this object
87 */
88 public EntityResolver2 getEntityResolver() {
89 return fEntityResolver;
90 } // getEntityResolver():EntityResolver2
91
92 //
93 // ExternalSubsetResolver methods
94 //
95
96 /**
97 * <p>Locates an external subset for documents which do not explicitly
98 * provide one. If no external subset is provided, this method should
99 * return <code>null</code>.</p>
100 *
101 * @param grammarDescription a description of the DTD
102 *
103 * @throws XNIException Thrown on general error.
104 * @throws IOException Thrown if resolved entity stream cannot be
105 * opened or some other i/o error occurs.
106 */
107 public XMLInputSource getExternalSubset(XMLDTDDescription grammarDescription)
108 throws XNIException, IOException {
109
110 if (fEntityResolver != null) {
111
112 String name = grammarDescription.getRootName();
113 String baseURI = grammarDescription.getBaseSystemId();
114
115 // Resolve using EntityResolver2
116 try {
117 InputSource inputSource = fEntityResolver.getExternalSubset(name, baseURI);
118 return (inputSource != null) ? createXMLInputSource(inputSource, baseURI) : null;
119 }
120 // error resolving external subset
121 catch (SAXException e) {
122 Exception ex = e.getException();
123 if (ex == null) {
124 ex = e;
125 }
126 throw new XNIException(ex);
127 }
128 }
129
130 // unable to resolve external subset
131 return null;
132
133 } // getExternalSubset(XMLDTDDescription):XMLInputSource
134
135 //
136 // XMLEntityResolver methods
137 //
138
139 /**
140 * Resolves an external parsed entity. If the entity cannot be
141 * resolved, this method should return null.
142 *
143 * @param resourceIdentifier contains the physical co-ordinates of the resource to be resolved
144 *
145 * @throws XNIException Thrown on general error.
146 * @throws IOException Thrown if resolved entity stream cannot be
147 * opened or some other i/o error occurs.
148 */
149 public XMLInputSource resolveEntity(XMLResourceIdentifier resourceIdentifier)
150 throws XNIException, IOException {
151
152 if (fEntityResolver != null) {
153
154 String pubId = resourceIdentifier.getPublicId();
155 String sysId = resourceIdentifier.getLiteralSystemId();
156 String baseURI = resourceIdentifier.getBaseSystemId();
157 String name = null;
158 if (resourceIdentifier instanceof XMLDTDDescription) {
159 name = "[dtd]";
160 }
161 else if (resourceIdentifier instanceof XMLEntityDescription) {
162 name = ((XMLEntityDescription) resourceIdentifier).getEntityName();
163 }
164
165 // When both pubId and sysId are null, the user's entity resolver
166 // can do nothing about it. We'd better not bother calling it.
167 // This happens when the resourceIdentifier is a GrammarDescription,
168 // which describes a schema grammar of some namespace, but without
169 // any schema location hint. -Sg
170 if (pubId == null && sysId == null) {
171 return null;
172 }
173
174 // Resolve using EntityResolver2
175 try {
176 InputSource inputSource =
177 fEntityResolver.resolveEntity(name, pubId, baseURI, sysId);
178 return (inputSource != null) ? createXMLInputSource(inputSource, baseURI) : null;
179 }
180 // error resolving entity
181 catch (SAXException e) {
182 Exception ex = e.getException();
183 if (ex == null) {
184 ex = e;
185 }
186 throw new XNIException(ex);
187 }
188 }
189
190 // unable to resolve entity
191 return null;
192
193 } // resolveEntity(XMLResourceIdentifier):XMLInputSource
194
195 /**
196 * Creates an XMLInputSource from a SAX InputSource.
197 */
198 private XMLInputSource createXMLInputSource(InputSource source, String baseURI) {
199
200 String publicId = source.getPublicId();
201 String systemId = source.getSystemId();
202 String baseSystemId = baseURI;
203 InputStream byteStream = source.getByteStream();
204 Reader charStream = source.getCharacterStream();
205 String encoding = source.getEncoding();
206 XMLInputSource xmlInputSource =
207 new XMLInputSource(publicId, systemId, baseSystemId);
208 xmlInputSource.setByteStream(byteStream);
209 xmlInputSource.setCharacterStream(charStream);
210 xmlInputSource.setEncoding(encoding);
211 return xmlInputSource;
212
213 } // createXMLInputSource(InputSource,String):XMLInputSource
214
215 } // class EntityResolver2Wrapper