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,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License.
018     */
019    
020    package org.apache.isis.core.progmodel.facets.actions.invoke;
021    
022    import java.lang.reflect.InvocationTargetException;
023    import java.lang.reflect.Method;
024    import java.util.Collections;
025    import java.util.List;
026    
027    import org.apache.isis.core.metamodel.adapter.ObjectAdapter;
028    import org.apache.isis.core.metamodel.adapter.map.AdapterMap;
029    import org.apache.isis.core.metamodel.adapter.util.InvokeUtils;
030    import org.apache.isis.core.metamodel.facetapi.FacetHolder;
031    import org.apache.isis.core.metamodel.facets.ImperativeFacet;
032    import org.apache.isis.core.metamodel.facets.actions.invoke.ActionInvocationFacetAbstract;
033    import org.apache.isis.core.metamodel.facets.typeof.ElementSpecificationProviderFromTypeOfFacet;
034    import org.apache.isis.core.metamodel.facets.typeof.TypeOfFacet;
035    import org.apache.isis.core.metamodel.spec.ObjectSpecification;
036    import org.apache.isis.core.metamodel.specloader.ReflectiveActionException;
037    import org.apache.log4j.Logger;
038    
039    public class ActionInvocationFacetViaMethod extends ActionInvocationFacetAbstract implements ImperativeFacet {
040    
041        private final static Logger LOG = Logger.getLogger(ActionInvocationFacetViaMethod.class);
042    
043        private final Method method;
044        private final int paramCount;
045        private final ObjectSpecification onType;
046        private final ObjectSpecification returnType;
047    
048        private final AdapterMap adapterMap;
049    
050        public ActionInvocationFacetViaMethod(final Method method, final ObjectSpecification onType,
051            final ObjectSpecification returnType, final FacetHolder holder, final AdapterMap adapterManager) {
052            super(holder);
053            this.method = method;
054            this.paramCount = method.getParameterTypes().length;
055            this.onType = onType;
056            this.returnType = returnType;
057            this.adapterMap = adapterManager;
058        }
059    
060        /**
061         * Returns a singleton list of the {@link Method} provided in the constructor.
062         */
063        @Override
064        public List<Method> getMethods() {
065            return Collections.singletonList(method);
066        }
067    
068        @Override
069        public ObjectSpecification getReturnType() {
070            return returnType;
071        }
072    
073        @Override
074        public ObjectSpecification getOnType() {
075            return onType;
076        }
077    
078        @Override
079        public ObjectAdapter invoke(final ObjectAdapter inObject, final ObjectAdapter[] parameters) {
080            if (parameters.length != paramCount) {
081                LOG.error(method + " requires " + paramCount + " parameters, not " + parameters.length);
082            }
083    
084            try {
085                final Object[] executionParameters = new Object[parameters.length];
086                for (int i = 0; i < parameters.length; i++) {
087                    executionParameters[i] = unwrap(parameters[i]);
088                }
089    
090                final Object object = unwrap(inObject);
091                final Object result = method.invoke(object, executionParameters);
092                if (LOG.isDebugEnabled()) {
093                    LOG.debug(" action result " + result);
094                }
095                if (result == null) {
096                    return null;
097                }
098    
099                final ObjectAdapter resultAdapter = getAdapterMap().adapterFor(result);
100                final TypeOfFacet typeOfFacet = getFacetHolder().getFacet(TypeOfFacet.class);
101                resultAdapter.setElementSpecificationProvider(ElementSpecificationProviderFromTypeOfFacet
102                    .createFrom(typeOfFacet));
103                return resultAdapter;
104    
105            } catch (final IllegalArgumentException e) {
106                throw e;
107            } catch (final InvocationTargetException e) {
108                if (e.getTargetException() instanceof IllegalStateException) {
109                    throw new ReflectiveActionException("IllegalStateException thrown while executing " + method + " "
110                        + e.getTargetException().getMessage(), e.getTargetException());
111                } else {
112                    InvokeUtils.invocationException("Exception executing " + method, e);
113                    return null;
114                }
115            } catch (final IllegalAccessException e) {
116                throw new ReflectiveActionException("Illegal access of " + method, e);
117            }
118        }
119    
120        private static Object unwrap(final ObjectAdapter adapter) {
121            return adapter == null ? null : adapter.getObject();
122        }
123    
124        @Override
125        public boolean impliesResolve() {
126            return true;
127        }
128    
129        @Override
130        public boolean impliesObjectChanged() {
131            return false;
132        }
133    
134        @Override
135        protected String toStringValues() {
136            return "method=" + method;
137        }
138    
139        // /////////////////////////////////////////////////////////
140        // Dependencies (from constructor)
141        // /////////////////////////////////////////////////////////
142    
143        private AdapterMap getAdapterMap() {
144            return adapterMap;
145        }
146    
147    }