001// Copyright 2008, 2010 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
017/**
018 * A cache for converting between class names and component (or other) classes. For component classes, ensures that the
019 * class is the transformed class.
020 */
021public interface ComponentClassCache
022{
023    /**
024     * Gets the Class instance for the given fully-qualified class name.
025     * 
026     * @param className
027     *            fully qualified class name, or a primitive type name, or an array name (in source format)
028     * @return the class instance
029     */
030    Class forName(String className);
031
032    /**
033     * Computes the default value for a field of the given type, returns the appropriate
034     * default value. This is typically null, but may be false (for a primitive boolean) or some
035     * version of 0 (for a primitive numeric field). Wrapper types will still be null.
036     * 
037     * @param className
038     *            type of field
039     * @since 5.2.0
040     */
041    Object defaultValueForType(String className);
042}