/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.core.util;
import java.util.Arrays;
/**
* Utilities to test the equivalence (see method-specific definitions) of any
* two object/array references.
*/
public class EquivalenceUtil {
/**
* Cannot be instantiated
*/
protected EquivalenceUtil() {
}
/**
* Tests whether two object references refer to equal objects. The object
* references can both be null, in which case they are also considered equal.
* @param obj1 object reference
* @param obj2 object reference
* @return true if both references are null, OR if neither is null and both
* objects are equal; false otherwise
*/
public static boolean areEqual(Object obj1, Object obj2) {
if (obj1 == obj2) {
return true;
} else if (obj1 == null || obj2 == null) {
return false;
} else {
return obj1.equals(obj2);
}
}
/**
* Tests whether two arrays are equivalent. This method ignores the array
* types, but checks the number of references in each array, and the
* equivalence of those references (in ascending index order).
* @param array1 an object array
* @param array2 an object array
*/
public static boolean areEquivalent(Object[] array1, Object[] array2) {
return Arrays.equals(array1, array2);
}
/**
* Tests whether two objects references are equivalent but not the same object.
* If both references are the same, this method will return false;
* @param obj1 object reference
* @param obj2 object reference
* @return true if the two references are unequal, and the objects they
* refer to are equal
*/
public static boolean areStrictlyEquivalent(Object obj1, Object obj2) {
if (obj1 == obj2 || obj1 == null || obj2 == null) {
return false;
}
return areEqual(obj1, obj2);
}
/**
* Tests whether the array references are equivalent, but are not the same.
* This method checks for the strict equivalence of each pair of objects
* in the two arrays (i.e. corresponding objects cannot be the same but must
* be equivalent) in ascending index order. This method also considers a
* null array and a 0-length array equivalent, and ignores the array type.
* @param array1 an object array
* @param array2 an object array
* @return true if the arrays are equivalent, but not the same.
*/
public static boolean areStrictlyEquivalent(Object[] array1, Object[] array2) {
if (array1 == array2) {
return false;
} else if (array1 == null) {
return array2.length == 0;
} else if (array2 == null) {
return array1.length == 0;
} else if (array1.length != array2.length) {
return false;
} else {
for (int i = 0; i < array1.length; i++) {
if (!areStrictlyEquivalent(array1[i], array2[i])) {
return false;
}
}
}
return true;
}
}