org.springframework.beans.support.PropertyComparator Maven / Gradle / Ivy
/*
* Copyright 2002-2012 the original author or authors.
*
* 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
*
* https://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.springframework.beans.support;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.BeansException;
import org.springframework.util.StringUtils;
/**
* PropertyComparator performs a comparison of two beans,
* evaluating the specified bean property via a BeanWrapper.
*
* @author Juergen Hoeller
* @author Jean-Pierre Pawlak
* @since 19.05.2003
* @see org.springframework.beans.BeanWrapper
*/
public class PropertyComparator implements Comparator {
protected final Log logger = LogFactory.getLog(getClass());
private final SortDefinition sortDefinition;
private final BeanWrapperImpl beanWrapper = new BeanWrapperImpl(false);
/**
* Create a new PropertyComparator for the given SortDefinition.
* @see MutableSortDefinition
*/
public PropertyComparator(SortDefinition sortDefinition) {
this.sortDefinition = sortDefinition;
}
/**
* Create a PropertyComparator for the given settings.
* @param property the property to compare
* @param ignoreCase whether upper and lower case in String values should be ignored
* @param ascending whether to sort ascending (true) or descending (false)
*/
public PropertyComparator(String property, boolean ignoreCase, boolean ascending) {
this.sortDefinition = new MutableSortDefinition(property, ignoreCase, ascending);
}
/**
* Return the SortDefinition that this comparator uses.
*/
public final SortDefinition getSortDefinition() {
return this.sortDefinition;
}
@Override
@SuppressWarnings("unchecked")
public int compare(T o1, T o2) {
Object v1 = getPropertyValue(o1);
Object v2 = getPropertyValue(o2);
if (this.sortDefinition.isIgnoreCase() && (v1 instanceof String) && (v2 instanceof String)) {
v1 = ((String) v1).toLowerCase();
v2 = ((String) v2).toLowerCase();
}
int result;
// Put an object with null property at the end of the sort result.
try {
if (v1 != null) {
result = (v2 != null ? ((Comparable