001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.beanutils2;
018
019import java.beans.PropertyDescriptor;
020import java.util.Set;
021
022/**
023 * <p>
024 * A context interface used during introspection for querying and setting property descriptors.
025 * </p>
026 * <p>
027 * An implementation of this interface is passed to {@link BeanIntrospector} objects during processing of a bean class. It allows the {@code BeanIntrospector}
028 * to deliver descriptors for properties it has detected. It is also possible to find out which properties have already been found by another
029 * {@code BeanIntrospector}; this allows multiple {@code BeanIntrospector} instances to collaborate.
030 * </p>
031 *
032 * @since 1.9
033 */
034public interface IntrospectionContext {
035
036    /**
037     * Adds the given property descriptor to this context. This method is called by a {@code BeanIntrospector} during introspection for each detected property.
038     * If this context already contains a descriptor for the affected property, it is overridden.
039     *
040     * @param desc the property descriptor
041     */
042    void addPropertyDescriptor(PropertyDescriptor desc);
043
044    /**
045     * Adds an array of property descriptors to this context. Using this method multiple descriptors can be added at once.
046     *
047     * @param descriptors the array of descriptors to be added
048     */
049    void addPropertyDescriptors(PropertyDescriptor[] descriptors);
050
051    /**
052     * Returns the descriptor for the property with the given name or <strong>null</strong> if this property is unknown.
053     *
054     * @param name the name of the property in question
055     * @return the descriptor for this property or <strong>null</strong> if this property is unknown
056     */
057    PropertyDescriptor getPropertyDescriptor(String name);
058
059    /**
060     * Returns the class that is subject of introspection.
061     *
062     * @return the current class
063     */
064    Class<?> getTargetClass();
065
066    /**
067     * Tests whether a descriptor for the property with the given name is already contained in this context. This method can be used for instance to prevent
068     * that an already existing property descriptor is overridden.
069     *
070     * @param name the name of the property in question
071     * @return <strong>true</strong> if a descriptor for this property has already been added, <strong>false</strong> otherwise
072     */
073    boolean hasProperty(String name);
074
075    /**
076     * Returns a set with the names of all properties known to this context.
077     *
078     * @return a set with the known property names
079     */
080    Set<String> propertyNames();
081
082    /**
083     * Removes the descriptor for the property with the given name.
084     *
085     * @param name the name of the affected property
086     */
087    void removePropertyDescriptor(String name);
088}