001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.bam;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.Processor;
021    import org.apache.camel.Expression;
022    import org.apache.camel.bam.ActivityRules;
023    import org.apache.camel.util.IntrospectionSupport;
024    import org.springframework.orm.jpa.JpaTemplate;
025    import org.springframework.transaction.support.TransactionTemplate;
026    
027    import java.util.List;
028    
029    /**
030     * @version $Revision: $
031     */
032    public class JpaBamProcessorSupport<T> extends BamProcessorSupport<T> {
033        private ActivityRules activityRules;
034        private JpaTemplate template;
035        private String findByKeyQuery;
036        private String keyPropertyName = "correlationKey";
037    
038        public JpaBamProcessorSupport(TransactionTemplate transactionTemplate, JpaTemplate template, Expression<Exchange> correlationKeyExpression, ActivityRules activityRules, Class<T> entitytype) {
039            super(transactionTemplate, correlationKeyExpression, entitytype);
040            this.activityRules = activityRules;
041            this.template = template;
042        }
043    
044        public JpaBamProcessorSupport(TransactionTemplate transactionTemplate, JpaTemplate template, Expression<Exchange> correlationKeyExpression, ActivityRules activityRules) {
045            super(transactionTemplate,  correlationKeyExpression);
046            this.activityRules = activityRules;
047            this.template = template;
048        }
049    
050        public String getFindByKeyQuery() {
051            if (findByKeyQuery == null) {
052                findByKeyQuery = createFindByKeyQuery();
053            }
054            return findByKeyQuery;
055        }
056    
057    
058        public void setFindByKeyQuery(String findByKeyQuery) {
059            this.findByKeyQuery = findByKeyQuery;
060        }
061    
062        public ActivityRules getActivity() {
063            return activityRules;
064        }
065    
066        public void setActivity(ActivityRules activityRules) {
067            this.activityRules = activityRules;
068        }
069    
070        public String getKeyPropertyName() {
071            return keyPropertyName;
072        }
073    
074        public void setKeyPropertyName(String keyPropertyName) {
075            this.keyPropertyName = keyPropertyName;
076        }
077    
078        public JpaTemplate getTemplate() {
079            return template;
080        }
081    
082        public void setTemplate(JpaTemplate template) {
083            this.template = template;
084        }
085    
086        // Implementatiom methods
087        //-----------------------------------------------------------------------
088        protected T loadEntity(Exchange exchange, Object key) {
089            List<T> list = template.find(getFindByKeyQuery(), key);
090            T entity = null;
091            if (!list.isEmpty()) {
092                entity = list.get(0);
093            }
094            if (entity == null) {
095                entity = createEntity(exchange, key);
096                setKeyProperty(entity, key);
097                template.persist(entity);
098            }
099            return entity;
100        }
101    
102        /**
103         * Sets the key property on the new entity
104         */
105        protected void setKeyProperty(T entity, Object key) {
106            IntrospectionSupport.setProperty(entity, getKeyPropertyName(), key);
107        }
108    
109        /**
110         * Create a new instance of the entity for the given key
111         */
112        protected T createEntity(Exchange exchange, Object key) {
113            return (T) exchange.getContext().getInjector().newInstance(getEntityType());
114        }
115    
116        protected void processEntity(Exchange exchange, T entity) throws Exception {
117            if (entity instanceof Processor) {
118                Processor processor = (Processor) entity;
119                processor.process(exchange);
120            }
121            else {
122                // TODO add other extension points - eg. passing in Activity
123                throw new IllegalArgumentException("No processor defined for this route");
124            }
125        }
126    
127        protected String createFindByKeyQuery() {
128            return "select x from " + getEntityType().getName() + " x where x." + getKeyPropertyName() + " = ?1";
129        }
130    }