EntityResolverWrapper.java revision 988:1c6c21d87aa4 
1/*
2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
3 */
4/*
5 * Licensed to the Apache Software Foundation (ASF) under one or more
6 * contributor license agreements.  See the NOTICE file distributed with
7 * this work for additional information regarding copyright ownership.
8 * The ASF licenses this file to You under the Apache License, Version 2.0
9 * (the "License"); you may not use this file except in compliance with
10 * the License.  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
21package com.sun.org.apache.xerces.internal.util;
22
23import java.io.InputStream;
24import java.io.IOException;
25import java.io.Reader;
26
27import com.sun.org.apache.xerces.internal.xni.XNIException;
28import com.sun.org.apache.xerces.internal.xni.XMLResourceIdentifier;
29import com.sun.org.apache.xerces.internal.xni.parser.XMLEntityResolver;
30import com.sun.org.apache.xerces.internal.xni.parser.XMLInputSource;
31import javax.xml.catalog.CatalogException;
32
33import org.xml.sax.EntityResolver;
34import org.xml.sax.InputSource;
35import org.xml.sax.SAXException;
36
37/**
38 * This class wraps a SAX entity resolver in an XNI entity resolver.
39 *
40 * @see EntityResolver
41 *
42 * @author Andy Clark, IBM
43 *
44 */
45public class EntityResolverWrapper
46    implements XMLEntityResolver {
47
48    //
49    // Data
50    //
51
52    /** The SAX entity resolver. */
53    protected EntityResolver fEntityResolver;
54
55    //
56    // Constructors
57    //
58
59    /** Default constructor. */
60    public EntityResolverWrapper() {}
61
62    /** Wraps the specified SAX entity resolver. */
63    public EntityResolverWrapper(EntityResolver entityResolver) {
64        setEntityResolver(entityResolver);
65    } // <init>(EntityResolver)
66
67    //
68    // Public methods
69    //
70
71    /** Sets the SAX entity resolver. */
72    public void setEntityResolver(EntityResolver entityResolver) {
73        fEntityResolver = entityResolver;
74    } // setEntityResolver(EntityResolver)
75
76    /** Returns the SAX entity resolver. */
77    public EntityResolver getEntityResolver() {
78        return fEntityResolver;
79    } // getEntityResolver():EntityResolver
80
81    //
82    // XMLEntityResolver methods
83    //
84
85    /**
86     * Resolves an external parsed entity. If the entity cannot be
87     * resolved, this method should return null.
88     *
89     * @param resourceIdentifier        contains the physical co-ordinates of the resource to be resolved
90     *
91     * @throws XNIException Thrown on general error.
92     * @throws IOException  Thrown if resolved entity stream cannot be
93     *                      opened or some other i/o error occurs.
94     */
95    public XMLInputSource resolveEntity(XMLResourceIdentifier resourceIdentifier)
96        throws XNIException, IOException {
97
98        // When both pubId and sysId are null, the user's entity resolver
99        // can do nothing about it. We'd better not bother calling it.
100        // This happens when the resourceIdentifier is a GrammarDescription,
101        // which describes a schema grammar of some namespace, but without
102        // any schema location hint. -Sg
103        String pubId = resourceIdentifier.getPublicId();
104        String sysId = resourceIdentifier.getExpandedSystemId();
105        if (pubId == null && sysId == null)
106            return null;
107
108        // resolve entity using SAX entity resolver
109        if (fEntityResolver != null && resourceIdentifier != null) {
110            try {
111                InputSource inputSource = fEntityResolver.resolveEntity(pubId, sysId);
112                if (inputSource != null) {
113                    String publicId = inputSource.getPublicId();
114                    String systemId = inputSource.getSystemId();
115                    String baseSystemId = resourceIdentifier.getBaseSystemId();
116                    InputStream byteStream = inputSource.getByteStream();
117                    Reader charStream = inputSource.getCharacterStream();
118                    String encoding = inputSource.getEncoding();
119                    XMLInputSource xmlInputSource =
120                        new XMLInputSource(publicId, systemId, baseSystemId, true);
121                    xmlInputSource.setByteStream(byteStream);
122                    xmlInputSource.setCharacterStream(charStream);
123                    xmlInputSource.setEncoding(encoding);
124                    return xmlInputSource;
125                }
126            }
127
128            // error resolving entity
129            catch (SAXException e) {
130                Exception ex = e.getException();
131                if (ex == null) {
132                    ex = e;
133                }
134                throw new XNIException(ex);
135            }
136
137            catch (CatalogException e) {
138                throw new XNIException(e);
139            }
140        }
141
142        // unable to resolve entity
143        return null;
144
145    } // resolveEntity(String,String,String):XMLInputSource
146}
147