001    // Copyright 2010, 2011 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.internal.transform;
016    
017    import org.apache.tapestry5.annotations.HeartbeatDeferred;
018    import org.apache.tapestry5.model.MutableComponentModel;
019    import org.apache.tapestry5.plastic.MethodAdvice;
020    import org.apache.tapestry5.plastic.MethodInvocation;
021    import org.apache.tapestry5.plastic.PlasticClass;
022    import org.apache.tapestry5.plastic.PlasticMethod;
023    import org.apache.tapestry5.services.Heartbeat;
024    import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
025    import org.apache.tapestry5.services.transform.TransformationSupport;
026    
027    public class HeartbeatDeferredWorker implements ComponentClassTransformWorker2
028    {
029        private final Heartbeat heartbeat;
030    
031        private final MethodAdvice deferredAdvice = new MethodAdvice()
032        {
033            public void advise(final MethodInvocation invocation)
034            {
035                heartbeat.defer(new Runnable()
036                {
037                    public void run()
038                    {
039                        invocation.proceed();
040                    }
041                });
042            }
043        };
044    
045        public HeartbeatDeferredWorker(Heartbeat heartbeat)
046        {
047            this.heartbeat = heartbeat;
048        }
049    
050        public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
051        {
052            for (PlasticMethod method : plasticClass.getMethodsWithAnnotation(HeartbeatDeferred.class))
053            {
054                deferMethodInvocations(method);
055            }
056        }
057    
058        void deferMethodInvocations(PlasticMethod method)
059        {
060            validateVoid(method);
061    
062            validateNoCheckedExceptions(method);
063    
064            method.addAdvice(deferredAdvice);
065    
066        }
067    
068        private void validateNoCheckedExceptions(PlasticMethod method)
069        {
070            if (method.getDescription().checkedExceptionTypes.length > 0)
071                throw new RuntimeException(
072                        String.format(
073                                "Method %s is not compatible with the @HeartbeatDeferred annotation, as it throws checked exceptions.",
074                                method.getMethodIdentifier()));
075        }
076    
077        private void validateVoid(PlasticMethod method)
078        {
079            if (!method.isVoid())
080                throw new RuntimeException(String.format(
081                        "Method %s is not compatible with the @HeartbeatDeferred annotation, as it is not a void method.",
082                        method.getMethodIdentifier()));
083        }
084    }