001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 package org.apache.oozie.service;
019
020 import org.apache.hadoop.conf.Configuration;
021 import org.apache.oozie.util.IOUtils;
022 import org.apache.oozie.ErrorCode;
023 import org.xml.sax.SAXException;
024
025 import javax.xml.XMLConstants;
026 import javax.xml.transform.stream.StreamSource;
027 import javax.xml.validation.Schema;
028 import javax.xml.validation.SchemaFactory;
029 import java.io.IOException;
030 import java.util.ArrayList;
031 import java.util.List;
032
033 /**
034 * Service that loads Oozie workflow definition schema and registered extension schemas.
035 */
036 public class WorkflowSchemaService implements Service {
037
038 public static final String CONF_PREFIX = Service.CONF_PREFIX + "WorkflowSchemaService.";
039
040 public static final String CONF_EXT_SCHEMAS = CONF_PREFIX + "ext.schemas";
041
042 private Schema dagSchema;
043
044 private static final String OOZIE_WORKFLOW_XSD = "oozie-workflow-0.1.xsd";
045
046 private Schema loadSchema(Configuration conf) throws SAXException, IOException {
047 List<StreamSource> sources = new ArrayList<StreamSource>();
048 sources.add(new StreamSource(IOUtils.getResourceAsStream(OOZIE_WORKFLOW_XSD, -1)));
049 String[] schemas = conf.getStrings(CONF_EXT_SCHEMAS);
050 if (schemas != null) {
051 for (String schema : schemas) {
052 sources.add(new StreamSource(IOUtils.getResourceAsStream(schema, -1)));
053 }
054 }
055 SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
056 return factory.newSchema(sources.toArray(new StreamSource[sources.size()]));
057 }
058
059 /**
060 * Initialize the service.
061 *
062 * @param services services instance.
063 * @throws ServiceException thrown if the service could not be initialized.
064 */
065 public void init(Services services) throws ServiceException {
066 try {
067 dagSchema = loadSchema(services.getConf());
068 }
069 catch (SAXException ex) {
070 throw new ServiceException(ErrorCode.E0130, ex.getMessage(), ex);
071 }
072 catch (IOException ex) {
073 throw new ServiceException(ErrorCode.E0131, ex.getMessage(), ex);
074 }
075 }
076
077 /**
078 * Return the public interface of the service.
079 *
080 * @return {@link WorkflowSchemaService}.
081 */
082 public Class<? extends Service> getInterface() {
083 return WorkflowSchemaService.class;
084 }
085
086 /**
087 * Destroy the service.
088 */
089 public void destroy() {
090 dagSchema = null;
091 }
092
093 /**
094 * Return the schema for XML validation of application definitions.
095 *
096 * @return the schema for XML validation of application definitions.
097 */
098 public Schema getSchema() {
099 return dagSchema;
100 }
101
102 }