    001    // Copyright 2006, 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
    015    package org.apache.tapestry5.ioc.services;
    016
    017    /**
    018     * A wrapper around the JavaBean Introspector that allows more manageable access to JavaBean properties of objects.
    019     * <p/>
    020     * Only provides access to <em>simple</em> properties. Indexed properties are ignored.
    021     * <p>
    022     * Starting in Tapestry 5.2, public fields can now be accessed as if they were properly JavaBean properties. Where there
    023     * is a name conflict, the true property will be favored over the field access.
    024     */
    025    public interface PropertyAccess
    026    {
    027        /**
    028         * Reads the value of a property.
    029         *
    030         * @throws UnsupportedOperationException
    031         *             if the property is write only
    032         * @throws IllegalArgumentException
    033         *             if property does not exist
    034         */
    035        Object get(Object instance, String propertyName);
    036
    037        /**
    038         * Updates the value of a property.
    039         *
    040         * @throws UnsupportedOperationException
    041         *             if the property is read only
    042         * @throws IllegalArgumentException
    043         *             if property does not exist
    044         */
    045        void set(Object instance, String propertyName, Object value);
    046
    047        /**
    048         * Returns the adapter for a particular object instance. A convienience over invoking {@link #getAdapter(Class)}.
    049         */
    050        ClassPropertyAdapter getAdapter(Object instance);
    051
    052        /**
    053         * Returns the adapter used to access properties within the indicated class.
    054         */
    055        ClassPropertyAdapter getAdapter(Class forClass);
    056
    057        /**
    058         * Discards all stored property access information, discarding all created class adapters.
    059         */
    060        void clearCache();
    061    }