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.util;
019    
020    import org.apache.hadoop.conf.Configuration;
021    import org.apache.oozie.service.ELService;
022    import org.apache.oozie.service.Services;
023    
024    import java.util.HashMap;
025    import java.util.Map;
026    
027    /**
028     * EL utilities
029     */
030    public class ELUtils {
031    
032        /**
033         * Resolves the application name using the configuration properties to resolve any EL variable.
034         *
035         * @param name name to EL resolve.
036         * @param conf configuration to use for resolving any EL variable in the name.
037         *
038         * @return the resolved application name.
039         *
040         * @throws Exception thrown if the name could not be EL resolved.
041         */
042        public static String resolveAppName(String name, Configuration conf) throws Exception {
043            ELService elService = Services.get().get(ELService.class);
044            ELEvaluator elEvaluator = elService.createEvaluator("job-submit");
045            Map<String, Object> map = new HashMap<String, Object>();
046            for (Map.Entry<String, String> entry : conf) {
047                map.put(entry.getKey(), entry.getValue());
048            }
049            elEvaluator.getContext().setVariables(map);
050            return elEvaluator.evaluate(name, String.class);
051        }
052    
053    }