Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.commons.beanutils; import org.apache.commons.collections.Predicate; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.lang.reflect.InvocationTargetException; /** * <p>Predicate implementation that applies the given <code>Predicate</code> * to the result of calling the given property getter. * </p> */ public class BeanPredicate implements Predicate { private final Log log = LogFactory.getLog(this.getClass()); /** Name of the property whose value will be predicated */ private String propertyName; /** <code>Predicate</code> to be applied to the property value */ private Predicate predicate; /** * Constructs a <code>BeanPredicate</code> that applies the given * <code>Predicate</code> to the named property value. * @param propertyName the name of the property whose value is to be predicated, * not null * @param predicate the <code>Predicate</code> to be applied, * not null */ public BeanPredicate(String propertyName, Predicate predicate) { this.propertyName = propertyName; this.predicate = predicate; } /** * Evaluates the given object by applying the {@link #getPredicate()} * to a property value named by {@link #getPropertyName()}. * * @param object The object being evaluated * @return the result of the predicate evaluation * @throws IllegalArgumentException when the property cannot be evaluated */ public boolean evaluate(Object object) { boolean evaluation = false; try { Object propValue = PropertyUtils.getProperty(object, propertyName); evaluation = predicate.evaluate(propValue); } catch (IllegalArgumentException e) { final String errorMsg = "Problem during evaluation."; log.error("ERROR: " + errorMsg, e); throw e; } catch (IllegalAccessException e) { final String errorMsg = "Unable to access the property provided."; log.error(errorMsg, e); throw new IllegalArgumentException(errorMsg); } catch (InvocationTargetException e) { final String errorMsg = "Exception occurred in property's getter"; log.error(errorMsg, e); throw new IllegalArgumentException(errorMsg); } catch (NoSuchMethodException e) { final String errorMsg = "Property not found."; log.error(errorMsg, e); throw new IllegalArgumentException(errorMsg); } return evaluation; } /** * Gets the name of the property whose value is to be predicated. * in the evaluation. * @return the property name, not null */ public String getPropertyName() { return propertyName; } /** * Sets the name of the property whose value is to be predicated. * @param propertyName the name of the property whose value is to be predicated, * not null */ public void setPropertyName(String propertyName) { this.propertyName = propertyName; } /** * Gets the <code>Predicate</code> to be applied to the value of the named property * during {@link #evaluate}. * @return <code>Predicate</code>, not null */ public Predicate getPredicate() { return predicate; } /** * Sets the <code>Predicate</code> to be applied to the value of the named property * during {@link #evaluate(Object)}. * @param predicate <code>Predicate</code>, not null */ public void setPredicate(Predicate predicate) { this.predicate = predicate; } }