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.transform.Source;
21 import javax.xml.validation.Schema;
22 import javax.xml.validation.SchemaFactory;
23
24 import org.springframework.core.io.Resource;
25 import org.springframework.util.Assert;
26 import org.springframework.xml.transform.ResourceSource;
27 import org.xml.sax.SAXException;
28 import org.xml.sax.XMLReader;
29 import org.xml.sax.helpers.XMLReaderFactory;
30
31 /**
32 * Convenient utility methods for loading of {@link Schema} objects, performing standard handling of input streams.
33 *
34 * @author Arjen Poutsma
35 * @since 1.0.0
36 */
37 public abstract class SchemaLoaderUtils {
38
39 /**
40 * Load schema from the given resource.
41 *
42 * @param resource the resource to load from
43 * @param schemaLanguage the language of the schema. Can be <code>XMLConstants.W3C_XML_SCHEMA_NS_URI</code> or
44 * <code>XMLConstants.RELAXNG_NS_URI</code>.
45 * @throws IOException if loading failed
46 * @throws SAXException if loading failed
47 * @see javax.xml.XMLConstants#W3C_XML_SCHEMA_NS_URI
48 * @see javax.xml.XMLConstants#RELAXNG_NS_URI
49 */
50 public static Schema loadSchema(Resource resource, String schemaLanguage) throws IOException, SAXException {
51 return loadSchema(new Resource[]{resource}, schemaLanguage);
52 }
53
54 /**
55 * Load schema from the given resource.
56 *
57 * @param resources the resources to load from
58 * @param schemaLanguage the language of the schema. Can be <code>XMLConstants.W3C_XML_SCHEMA_NS_URI</code> or
59 * <code>XMLConstants.RELAXNG_NS_URI</code>.
60 * @throws IOException if loading failed
61 * @throws SAXException if loading failed
62 * @see javax.xml.XMLConstants#W3C_XML_SCHEMA_NS_URI
63 * @see javax.xml.XMLConstants#RELAXNG_NS_URI
64 */
65 public static Schema loadSchema(Resource[] resources, String schemaLanguage) throws IOException, SAXException {
66 Assert.notEmpty(resources, "No resources given");
67 Assert.hasLength(schemaLanguage, "No schema language provided");
68 Source[] schemaSources = new Source[resources.length];
69 XMLReader xmlReader = XMLReaderFactory.createXMLReader();
70 xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
71 for (int i = 0; i < resources.length; i++) {
72 Assert.notNull(resources[i], "Resource is null");
73 Assert.isTrue(resources[i].exists(), "Resource " + resources[i] + " does not exist");
74 schemaSources[i] = new ResourceSource(xmlReader, resources[i]);
75 }
76 SchemaFactory schemaFactory = SchemaFactory.newInstance(schemaLanguage);
77 return schemaFactory.newSchema(schemaSources);
78 }
79
80 /** Retrieves the URL from the given resource as System ID. Returns <code>null</code> if it cannot be openened. */
81 public static String getSystemId(Resource resource) {
82 try {
83 return resource.getURL().toString();
84 }
85 catch (IOException e) {
86 return null;
87 }
88 }
89 }