001/*
002 * Copyright 2006-2008 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.springframework.batch.core.configuration.xml;
017
018import java.util.Collection;
019import java.util.List;
020
021import org.springframework.beans.MutablePropertyValues;
022import org.springframework.beans.factory.config.BeanDefinition;
023import org.springframework.beans.factory.config.RuntimeBeanReference;
024import org.springframework.beans.factory.support.AbstractBeanDefinition;
025import org.springframework.beans.factory.support.BeanDefinitionBuilder;
026import org.springframework.beans.factory.support.GenericBeanDefinition;
027import org.springframework.beans.factory.support.ManagedList;
028import org.springframework.beans.factory.xml.ParserContext;
029import org.springframework.core.task.TaskExecutor;
030import org.springframework.util.StringUtils;
031import org.springframework.util.xml.DomUtils;
032import org.w3c.dom.Element;
033
034/**
035 * Internal parser for the <split/> elements inside a job. A split element
036 * optionally references a bean definition for a {@link TaskExecutor} and goes
037 * on to list a set of transitions to other states with <next on="pattern"
038 * to="stepName"/>. Used by the {@link JobParser}.
039 * 
040 * @see JobParser
041 * 
042 * @author Dave Syer
043 * 
044 */
045public class SplitParser {
046
047        private static final String PARENT_ATTR = "parent";
048
049        private final String jobFactoryRef;
050
051        /**
052         * Construct a {@link InlineFlowParser} using the provided job repository
053         * ref.
054         * 
055         * @param jobFactoryRef the reference to the {@link JobParserJobFactoryBean}
056         * from the enclosing tag
057         */
058        public SplitParser(String jobFactoryRef) {
059                this.jobFactoryRef = jobFactoryRef;
060        }
061
062        /**
063         * Parse the split and turn it into a list of transitions.
064         * 
065         * @param element the <split/gt; element to parse
066         * @param parserContext the parser context for the bean factory
067         * @return a collection of bean definitions for
068         * {@link org.springframework.batch.core.job.flow.support.StateTransition}
069         * instances objects
070         */
071        public Collection<BeanDefinition> parse(Element element, ParserContext parserContext) {
072
073                String idAttribute = element.getAttribute("id");
074
075                BeanDefinitionBuilder stateBuilder = BeanDefinitionBuilder
076                                .genericBeanDefinition("org.springframework.batch.core.job.flow.support.state.SplitState");
077
078                String taskExecutorBeanId = element.getAttribute("task-executor");
079                if (StringUtils.hasText(taskExecutorBeanId)) {
080                        RuntimeBeanReference taskExecutorRef = new RuntimeBeanReference(taskExecutorBeanId);
081                        stateBuilder.addPropertyValue("taskExecutor", taskExecutorRef);
082                }
083
084                List<Element> flowElements = DomUtils.getChildElementsByTagName(element, "flow");
085
086                if (flowElements.size() < 2) {
087                        parserContext.getReaderContext().error("A <split/> must contain at least two 'flow' elements.", element);
088                }
089
090                Collection<BeanDefinition> flows = new ManagedList<BeanDefinition>();
091                int i = 0;
092                String prefix = idAttribute;
093                for (Element nextElement : flowElements) {
094                        String ref = nextElement.getAttribute(PARENT_ATTR);
095                        if (StringUtils.hasText(ref)) {
096                                if (nextElement.getElementsByTagName("*").getLength() > 0) {
097                                        parserContext.getReaderContext().error(
098                                                        "A <flow/> in a <split/> must have ref= or nested <flow/>, but not both.", nextElement);
099                                }
100                                AbstractBeanDefinition flowDefinition = new GenericBeanDefinition();
101                                flowDefinition.setParentName(ref);
102                                MutablePropertyValues propertyValues = flowDefinition.getPropertyValues();
103                                propertyValues.addPropertyValue("name", prefix + "." + i);
104                                flows.add(flowDefinition);
105                        }
106                        else {
107                                InlineFlowParser flowParser = new InlineFlowParser(prefix + "." + i, jobFactoryRef);
108                                flows.add(flowParser.parse(nextElement, parserContext));
109                        }
110                        i++;
111                }
112
113                stateBuilder.addConstructorArgValue(flows);
114                stateBuilder.addConstructorArgValue(prefix);
115
116                return InlineFlowParser.getNextElements(parserContext, stateBuilder.getBeanDefinition(), element);
117
118        }
119
120}