1 /*
2 * Copyright 2006 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.xml.validation;
18
19 import java.io.IOException;
20 import javax.xml.validation.Validator;
21
22 import org.apache.commons.logging.Log;
23 import org.apache.commons.logging.LogFactory;
24 import org.springframework.core.io.Resource;
25 import org.springframework.util.Assert;
26 import org.springframework.xml.JaxpVersion;
27
28 /**
29 * Factory for {@link XmlValidator} objects, being aware of JAXP 1.3 {@link Validator}s, and JAXP 1.0 parsing
30 * capababilities. Mainly for internal use within the framework.
31 * <p/>
32 * The goal of this class is to avoid runtime dependencies on JAXP 1.3 by using the best validation implementation that
33 * is available. Prefers JAXP 1.3 {@link XmlValidator} implementations to a custom, SAX-based implementation.
34 *
35 * @author Arjen Poutsma
36 * @see XmlValidator
37 * @since 1.0.0
38 */
39 public abstract class XmlValidatorFactory {
40
41 private static final Log logger = LogFactory.getLog(XmlValidatorFactory.class);
42
43 /** Constant that defines a W3C XML Schema. */
44 public static final String SCHEMA_W3C_XML = "http://www.w3.org/2001/XMLSchema";
45
46 /** Constant that defines a RELAX NG Schema. */
47 public static final String SCHEMA_RELAX_NG = "http://relaxng.org/ns/structure/1.0";
48
49 /**
50 * Create a {@link XmlValidator} with the given schema resource and schema language type. The schema language must
51 * be one of the <code>SCHEMA_XXX</code> constants.
52 *
53 * @param schemaResource a resource that locates the schema to validate against
54 * @param schemaLanguage the language of the schema
55 * @return a validator
56 * @throws IOException if the schema resource cannot be read
57 * @throws IllegalArgumentException if the schema language is not supported
58 * @throws IllegalStateException if JAXP 1.0 cannot be located
59 * @throws XmlValidationException if a <code>XmlValidator</code> cannot be created
60 * @see #SCHEMA_RELAX_NG
61 * @see #SCHEMA_W3C_XML
62 */
63 public static XmlValidator createValidator(Resource schemaResource, String schemaLanguage) throws IOException {
64 return createValidator(new Resource[]{schemaResource}, schemaLanguage);
65 }
66
67 /**
68 * Create a {@link XmlValidator} with the given schema resources and schema language type. The schema language must
69 * be one of the <code>SCHEMA_XXX</code> constants.
70 *
71 * @param schemaResources an array of resource that locate the schemas to validate against
72 * @param schemaLanguage the language of the schemas
73 * @return a validator
74 * @throws IOException if the schema resource cannot be read
75 * @throws IllegalArgumentException if the schema language is not supported
76 * @throws IllegalStateException if JAXP 1.0 cannot be located
77 * @throws XmlValidationException if a <code>XmlValidator</code> cannot be created
78 * @see #SCHEMA_RELAX_NG
79 * @see #SCHEMA_W3C_XML
80 */
81 public static XmlValidator createValidator(Resource[] schemaResources, String schemaLanguage) throws IOException {
82 Assert.notEmpty(schemaResources, "No resources given");
83 Assert.hasLength(schemaLanguage, "No schema language provided");
84 Assert.isTrue(SCHEMA_W3C_XML.equals(schemaLanguage) || SCHEMA_RELAX_NG.equals(schemaLanguage),
85 "Invalid schema language: " + schemaLanguage);
86 for (int i = 0; i < schemaResources.length; i++) {
87 Assert.isTrue(schemaResources[i].exists(), "schema [" + schemaResources[i] + "] does not exist");
88 }
89 if (JaxpVersion.getJaxpVersion() >= JaxpVersion.JAXP_13) {
90 logger.trace("Creating JAXP 1.3 XmlValidator");
91 return Jaxp13ValidatorFactory.createValidator(schemaResources, schemaLanguage);
92 }
93 else if (JaxpVersion.getJaxpVersion() >= JaxpVersion.JAXP_10) {
94 logger.trace("Creating JAXP 1.0 XmlValidator");
95 return Jaxp10ValidatorFactory.createValidator(schemaResources, schemaLanguage);
96 }
97 else {
98 throw new IllegalStateException("Could not locate JAXP 1.0 or higher.");
99 }
100 }
101
102 }