/*
* Copyright 2002-2009 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
*
* 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.springframework.expression;
/**
* Instances of a type comparator should be able to compare pairs of objects for equality, the specification of the
* return value is the same as for {@link Comparable}.
*
* @author Andy Clement
* @since 3.0
*/
public interface TypeComparator {
/**
* Compare two objects.
* @param firstObject the first object
* @param secondObject the second object
* @return 0 if they are equal, <0 if the first is smaller than the second, or >0 if the first is larger than the
* second
* @throws EvaluationException if a problem occurs during comparison (or they are not comparable)
*/
int compare(Object firstObject, Object secondObject) throws EvaluationException;
/**
* Return true if the comparator can compare these two objects
* @param firstObject the first object
* @param secondObject the second object
* @return true if the comparator can compare these objects
*/
boolean canCompare(Object firstObject, Object secondObject);
}
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