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.bam.Activity;
021    import org.apache.camel.bam.model.ActivityState;
022    import org.apache.camel.bam.model.ProcessInstance;
023    
024    /**
025     * @version $Revision: $
026     */
027    public abstract class ActivityExpressionSupport extends ProcessExpressionSupport<ProcessInstance> {
028        private Activity activity;
029    
030        protected ActivityExpressionSupport(Activity activity) {
031            super(ProcessInstance.class);
032            this.activity = activity;
033        }
034    
035        protected Object evaluate(Exchange exchange, ProcessInstance processEntity) {
036            ActivityState state = processEntity.getActivityState(activity);
037            if (state != null) {
038                return evaluateState(exchange, state);
039            }
040            return null;
041        }
042    
043        protected abstract Object evaluateState(Exchange exchange, ActivityState state);
044    }