org.springframework.xml.validation.SchemaLoaderUtils Maven / Gradle / Ivy
/*
* Copyright 2005-2022 the original author or authors.
*
* Licensed 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.
*/
package org.springframework.xml.validation;
import java.io.IOException;
import javax.xml.transform.Source;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import org.springframework.core.io.Resource;
import org.springframework.util.Assert;
import org.springframework.xml.transform.ResourceSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
/**
* Convenient utility methods for loading of {@link Schema} objects, performing standard handling of input streams.
*
* @author Arjen Poutsma
* @since 1.0.0
*/
public abstract class SchemaLoaderUtils {
/**
* Load schema from the given resource.
*
* @param resource the resource to load from
* @param schemaLanguage the language of the schema. Can be {@code XMLConstants.W3C_XML_SCHEMA_NS_URI} or
* {@code XMLConstants.RELAXNG_NS_URI}.
* @throws IOException if loading failed
* @throws SAXException if loading failed
* @see javax.xml.XMLConstants#W3C_XML_SCHEMA_NS_URI
* @see javax.xml.XMLConstants#RELAXNG_NS_URI
*/
public static Schema loadSchema(Resource resource, String schemaLanguage) throws IOException, SAXException {
return loadSchema(new Resource[] { resource }, schemaLanguage);
}
/**
* Load schema from the given resource.
*
* @param resources the resources to load from
* @param schemaLanguage the language of the schema. Can be {@code XMLConstants.W3C_XML_SCHEMA_NS_URI} or
* {@code XMLConstants.RELAXNG_NS_URI}.
* @throws IOException if loading failed
* @throws SAXException if loading failed
* @see javax.xml.XMLConstants#W3C_XML_SCHEMA_NS_URI
* @see javax.xml.XMLConstants#RELAXNG_NS_URI
*/
public static Schema loadSchema(Resource[] resources, String schemaLanguage) throws IOException, SAXException {
Assert.notEmpty(resources, "No resources given");
Assert.hasLength(schemaLanguage, "No schema language provided");
Source[] schemaSources = new Source[resources.length];
XMLReader xmlReader = XMLReaderFactoryUtils.createXMLReader();
xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
for (int i = 0; i < resources.length; i++) {
Assert.notNull(resources[i], "Resource is null");
Assert.isTrue(resources[i].exists(), "Resource " + resources[i] + " does not exist");
schemaSources[i] = new ResourceSource(xmlReader, resources[i]);
}
SchemaFactory schemaFactory = SchemaFactoryUtils.newInstance(schemaLanguage);
return schemaFactory.newSchema(schemaSources);
}
/** Retrieves the URL from the given resource as System ID. Returns {@code null} if it cannot be opened. */
public static String getSystemId(Resource resource) {
try {
return resource.getURL().toString();
} catch (IOException e) {
return null;
}
}
}