1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
<?xml version='1.0' encoding='UTF-8'?>
<!--
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
-->
<!DOCTYPE faqs SYSTEM 'dtd/faqs.dtd'>
<faqs title='Configuring Parser'>
<faq title='Validation and infoset augmentation'>
<q>What's the result of having a DTD validator or XML Schema validator in the pipeline?</q>
<a>
<p>
If a validator is included in the pipeline, the assessment is
done, whether the validation feature is set to true or false.
The validation feature only enables the validation constraint error
reporting and it does not control the infoset augmentation: if a
validator is included in the pipeline the parser will augment the
infoset according to the grammar specified for the instance document.
</p>
</a>
</faq>
<faq title='Default Parser Configuration'>
<q>What validation behavior do I expect from the default parser configuration?</q>
<a>
<p>
The default configuration (&DefaultConfigLong;) includes the DTD validator
and the document scanner (which are both capable of namespace binding). Thus, the
<link idref='features' anchor="validation">validation feature</link> will enable
validation against a DTD only. To allow validation against XML Schemas you must turn
on the <link idref='features' anchor="validation">validation feature</link> and the
<link idref='features' anchor="validation.schema">schema feature</link>, and
XML Schema Validator will be inserted in the pipeline. if you've created your own
configuration which does not extend &DefaultConfig; (or another
suitable configuration included with the parser), you must make sure that your
configuration inserts all needed validators in the pipeline.
</p>
</a>
</faq>
<faq title='Validation Features'>
<q>What happens if I set both validation and schema validation features on?</q>
<a>
<p>
If both validators are present in the pipeline (this is the default behavior), then
</p>
<ul>
<li>if the instance document has only a DTD grammar
(DOCTYPE before the root element), then only DTD
validation errors are reported;</li>
<li>if the instance document has only XML Schema grammars,
then only XML Schema validation errors are reported</li>
<li>if the instance document has both DTD and XML Schema
grammars, validation errors for both DTD and XML
Schema are reported;</li>
<li>if no grammar can be found for the instance document,
the last validator in the pipeline will report validation errors.
</li>
</ul>
<p>
An application may choose to create a configuration that does not have a DTD
validator but has an XML Schema validator. This will turn Xerces into a
non-compliant processor according to XML 1.0 and XML Schema specifications,
thus the validation/augmentation outcome is undefined.
</p>
</a>
</faq>
<faq title='Validation against a specific schema language'>
<q>How can I tell the parser to validate against XML Schema and not to report DTD validation errors?</q>
<a>
<p>
Using JAXP you can instruct the parser to validate against XML Schema only. The JAXP 1.4
Validation API allows you to build an in-memory representation of an XML Schema which
you can then set on a parser factory. Parsers created from the factory will validate
documents using the schema object you specified.
</p>
<p>By doing the following you can configure a SAX parser or DocumentBuilder to validate against XML Schema only:</p>
<source>import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
...
StreamSource[] sources = /* created by your application */;
SchemaFactory factory =
SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
Schema schema = factory.newSchema(sources);
/** Setup SAX parser for schema validation. */
SAXParserFactory spf = SAXParserFactory.newInstance();
spf.setNamespaceAware(true);
spf.setSchema(schema);
SAXParser parser = spf.newSAXParser();
/** Setup DocumentBuilder for schema validation. */
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware(true);
dbf.setSchema(schema);
DocumentBuilder db = dbf.newDocumentBuilder();
...
</source>
<p>
Changing the value of the schema language parameter passed to <code>SchemaFactory.newInstance()</code>
to <code>http://www.w3.org/XML/XMLSchema/v1.1</code> will create a processor which supports XML Schema 1.1.
</p>
<source>import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
...
StreamSource[] sources = /* created by your application */;
SchemaFactory factory =
SchemaFactory.newInstance("http://www.w3.org/XML/XMLSchema/v1.1");
Schema schema = factory.newSchema(sources);
...
</source>
<p>
Another option is to use the JAXP schema language property defined by JAXP 1.2. If the schema
language property has been set to <code>http://www.w3.org/2001/XMLSchema</code>
and the parser has been configured to validate then your documents will be validated against
XML Schema only, even if they have a DTD.
</p>
<p>By doing the following you can configure a SAX parser to validate against XML Schema only:</p>
<source>import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
...
SAXParserFactory spf = SAXParserFactory.newInstance();
spf.setValidating(true);
spf.setNamespaceAware(true);
SAXParser parser = spf.newSAXParser();
parser.setProperty(
"http://java.sun.com/xml/jaxp/properties/schemaLanguage",
"http://www.w3.org/2001/XMLSchema");
...
</source>
<p>For a DocumentBuilder this can be accomplished by doing the following:</p>
<source>import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
...
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware(true);
dbf.setValidating(true);
dbf.setAttribute(
"http://java.sun.com/xml/jaxp/properties/schemaLanguage",
"http://www.w3.org/2001/XMLSchema");
DocumentBuilder docBuilder = dbf.newDocumentBuilder();
...
</source>
</a>
</faq>
</faqs>
|
