001// Copyright 2004, 2005 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
015package org.apache.hivemind.service.impl;
016
017import java.util.HashMap;
018import java.util.Map;
019
020import org.apache.hivemind.Location;
021import org.apache.hivemind.ServiceImplementationFactoryParameters;
022import org.apache.hivemind.internal.Module;
023import org.apache.hivemind.schema.Translator;
024import org.apache.hivemind.util.ConstructorUtils;
025
026/**
027 * Implementation of {@link org.apache.hivemind.service.impl.BuilderFacet} that stores a value. This
028 * corresponds to the <set> type elements and all constructor parameter elements. The value is
029 * not resolved until needed using a specified {@link Translator}.
030 * 
031 * @author Howard Lewis Ship
032 */
033public class BuilderPropertyFacet extends BuilderFacet
034{
035    private String _translatorName;
036
037    private String _literalValue;
038
039    /**
040     * Cache for translated values to prevent calling
041     * {@link Translator#translate(Module, Class, String, Location)} twice.
042     */
043    private Map _valuesCache = new HashMap();
044
045    public Object getFacetValue(ServiceImplementationFactoryParameters factoryParameters,
046            Class targetType)
047    {
048        Object result = _valuesCache.get(targetType);
049
050        if (result == null)
051        {
052            Translator translator = factoryParameters.getInvokingModule().getTranslator(
053                    _translatorName);
054
055            result = translator.translate(
056                    factoryParameters.getInvokingModule(),
057                    targetType,
058                    _literalValue,
059                    getLocation());
060
061            _valuesCache.put(targetType, result);
062        }
063
064        return result;
065    }
066
067    public boolean isAssignableToType(ServiceImplementationFactoryParameters factoryParameters,
068            Class targetType)
069    {
070        // TODO should Translator declare an analoguous isAssignableToType method?
071        Object facetValue = getFacetValue(factoryParameters, targetType);
072
073        if (facetValue == null)
074            return !targetType.isPrimitive();
075
076        return ConstructorUtils.isCompatible(targetType, facetValue.getClass());
077    }
078
079    /** @since 1.1 */
080    public void setTranslator(String translatorName)
081    {
082        _translatorName = translatorName;
083    }
084
085    public void setValue(String value)
086    {
087        _literalValue = value;
088    }
089
090}