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 */
018package org.apache.oozie.util;
019
020import java.util.Iterator;
021import java.util.regex.Matcher;
022import java.util.regex.Pattern;
023import org.apache.oozie.ErrorCode;
024import org.jdom.Element;
025import org.jdom.Namespace;
026
027import org.apache.hadoop.conf.Configuration;
028
029/**
030 * Utility class to parse and verify the <parameters> section in a workflow or coordinator job
031 */
032public abstract class ParameterVerifier 
033{
034    private static final Pattern nsVersionPattern = Pattern.compile("uri:oozie:(workflow|coordinator|bundle):(\\d+.\\d+)");
035    
036    private static final double workflowMinVersion = 0.4;
037    private static final double coordinatorMinVersion = 0.4;
038    private static final double bundleMinVersion = 0.2;
039    
040    /**
041     * Verify the parameters section (if supported in the schema)
042     *
043     * @param conf The job configuration
044     * @param rootElement The root element of the workflow, coordinator, or bundle definition
045     * @throws ParameterVerifierException If required parameters are not defined and have no default values, or if a name is empty
046     */
047    public static void verifyParameters(Configuration conf, Element rootElement) throws ParameterVerifierException {
048        ParamChecker.notNull(conf, "conf");
049        if (rootElement == null) {
050            return;
051        }
052        
053        if (supportsParameters(rootElement.getNamespaceURI())) {
054            Element params = rootElement.getChild("parameters", rootElement.getNamespace());
055            if (params != null) {
056                int numMissing = 0;
057                StringBuilder missingParameters = new StringBuilder();
058                Namespace paramsNs = params.getNamespace();
059                Iterator<Element> it = params.getChildren("property", paramsNs).iterator();
060                while (it.hasNext()) {
061                    Element prop = it.next();
062                    String name = prop.getChildTextTrim("name", paramsNs);
063                    if (name != null) {
064                        if (name.isEmpty()) {
065                            throw new ParameterVerifierException(ErrorCode.E0739);
066                        }
067                        if (conf.get(name) == null) {
068                            String defaultValue = prop.getChildTextTrim("value", paramsNs);
069                            if (defaultValue != null) {
070                                conf.set(name, defaultValue);
071                            } else {
072                                missingParameters.append(name);
073                                missingParameters.append(", ");
074                                numMissing++;
075                            }
076                        }
077                    }
078                }
079                if (numMissing > 0) {
080                    missingParameters.setLength(missingParameters.length() - 2);    //remove the trailing ", "
081                    throw new ParameterVerifierException(ErrorCode.E0738, numMissing, missingParameters.toString());
082                }
083            } else {
084                // Log a warning when the <parameters> section is missing
085                XLog.getLog(ParameterVerifier.class).warn("The application does not define formal parameters in its XML "
086                        + "definition");
087            }
088        }
089    }
090    
091    static boolean supportsParameters(String namespaceURI) {
092        boolean supports = false;
093        Matcher m = nsVersionPattern.matcher(namespaceURI);
094        if (m.matches() && m.groupCount() == 2) {
095            String type = m.group(1);
096            double ver = Double.parseDouble(m.group(2));
097            supports = ((type.equals("workflow") && ver >= workflowMinVersion) || 
098                    (type.equals("coordinator") && ver >= coordinatorMinVersion) || 
099                    (type.equals("bundle") && ver >= bundleMinVersion));
100        }
101        return supports;
102    }
103}