001// Copyright 2008, 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
015package org.apache.tapestry5.internal.services;
016
017import org.apache.tapestry5.internal.plastic.PlasticInternalUtils;
018import org.apache.tapestry5.ioc.annotations.PostInjection;
019import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
020import org.apache.tapestry5.ioc.services.PlasticProxyFactory;
021import org.apache.tapestry5.ioc.services.TypeCoercer;
022import org.apache.tapestry5.services.ComponentClasses;
023import org.apache.tapestry5.services.ComponentLayer;
024import org.apache.tapestry5.services.InvalidationEventHub;
025import org.apache.tapestry5.services.InvalidationListener;
026
027import javax.annotation.PostConstruct;
028import java.util.Map;
029
030public class ComponentClassCacheImpl implements ComponentClassCache
031{
032    private final Map<String, Class> cache = CollectionFactory.newConcurrentMap();
033
034    private final PlasticProxyFactory plasticFactory;
035
036    private final TypeCoercer typeCoercer;
037
038    public ComponentClassCacheImpl(@ComponentLayer
039    PlasticProxyFactory plasticFactory, TypeCoercer typeCoercer)
040    {
041        this.plasticFactory = plasticFactory;
042        this.typeCoercer = typeCoercer;
043    }
044
045    @PostInjection
046    public void setupInvalidation(@ComponentClasses InvalidationEventHub hub) {
047        hub.clearOnInvalidation(cache);
048    }
049
050    @SuppressWarnings("unchecked")
051    public Object defaultValueForType(String className)
052    {
053        Class clazz = forName(className);
054
055        if (!clazz.isPrimitive())
056            return null;
057
058        // Remembering that 0 coerces to boolean false, this covers all the primitive
059        // types (boolean, int, short, etc.)
060        return typeCoercer.coerce(0, clazz);
061    }
062
063    public Class forName(String className)
064    {
065        Class result = cache.get(className);
066
067        if (result == null)
068        {
069            result = lookupClassForType(className);
070
071            cache.put(className, result);
072        }
073
074        return result;
075    }
076
077    private Class lookupClassForType(String className)
078    {
079        ClassLoader componentLoader = plasticFactory.getClassLoader();
080        try
081        {
082            return PlasticInternalUtils.toClass(componentLoader, className);
083        }
084        catch (ClassNotFoundException ex)
085        {
086            throw new RuntimeException(ex);
087        }
088    }
089}