Java tutorial
/* * Copyright 2005 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License") * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package net.sf.beanlib; import java.util.HashSet; import java.util.Set; import org.apache.commons.lang.builder.EqualsBuilder; /** * Used to uniquely identify a Collection or Map property of a JavaBean object. * * @author Joe D. Velopar */ public class CollectionPropertyName<T> { public static final CollectionPropertyName<?>[] EMPTY_ARRAY = {}; private final Class<T> declaringClass; private final String collectionProperty; private final int hashCode; private final BeanGetter beanGetter = new BeanGetter(); /** Convenient factory method. */ public static <T> CollectionPropertyName<T>[] createCollectionPropertyNames(Class<T> declaringClass, String[] collectionProperties) { Set<CollectionPropertyName<T>> set = new HashSet<CollectionPropertyName<T>>(); for (String s : collectionProperties) set.add(new CollectionPropertyName<T>(declaringClass, s)); @SuppressWarnings("unchecked") CollectionPropertyName<T>[] ret = (CollectionPropertyName<T>[]) set.toArray(EMPTY_ARRAY); return ret; } /** * @param declaringClass declaring class of the Collection or Map property. * @param collectionProperty Collection or Map property name. */ public CollectionPropertyName(Class<T> declaringClass, String collectionProperty) { this.declaringClass = declaringClass; this.collectionProperty = collectionProperty; this.hashCode = beanGetter.getBeanHashCode(this); } public Class<T> getDeclaringClass() { return declaringClass; } public String getCollectionProperty() { return collectionProperty; } @Override public boolean equals(Object obj) { if (!(obj instanceof CollectionPropertyName)) return false; CollectionPropertyName<?> that = (CollectionPropertyName<?>) obj; return new EqualsBuilder().append(this.declaringClass, that.declaringClass) .append(this.collectionProperty, that.collectionProperty).isEquals(); } @Override public int hashCode() { return this.hashCode; } }