org.opencastproject.util.EqualsUtil Maven / Gradle / Ivy
/*
* Licensed to The Apereo Foundation under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
*
* The Apereo Foundation licenses this file to you under the Educational
* Community 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://opensource.org/licenses/ecl2.txt
*
* 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.opencastproject.util;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Collectors;
/** Utility function helping to implement equality. */
public final class EqualsUtil {
private EqualsUtil() {
}
/** Check if a and b are equal. Each of them may be null. */
@Deprecated
public static boolean eqObj(Object a, Object b) {
return Objects.equals(a, b);
}
/** Check if a and b are equal. Each of them may be null. */
@Deprecated
public static boolean eq(Object a, Object b) {
return Objects.equals(a, b);
}
/** Check if a and b are not equal. Each of them may be null. */
public static boolean ne(Object a, Object b) {
return !eq(a, b);
}
/** Check if a and b have the same class ({@link Object#getClass()}). Each may be null. */
public static boolean eqClasses(Object a, Object b) {
return bothNotNull(a, b) && a.getClass().equals(b.getClass());
}
/**
* Compare the (distinct) elements of two lists for equality treating the lists as sets.
*
* Sets by definition do not allow multiplicity of elements; a set is a (possibly empty) collection of distinct elements.
* As Lists may contain non-unique entries, this method removes duplicates before continuing with the comparison check.
*
* Examples of
* 1. equality: {1, 2} = {2, 1} = {1, 1, 2} = {1, 2, 2, 1, 2}, null = null
* 2. unequal: {1, 2, 2} != {1, 2, 3}, null != {}
*/
public static boolean eqListUnsorted(List as, List bs) {
if (as == null || bs == null) {
return eqObj(as, bs);
}
as = as.stream().distinct().collect(Collectors.toList());
bs = bs.stream().distinct().collect(Collectors.toList());
if (as.size() != bs.size()) {
return false;
}
for (Object a : as) {
if (!bs.contains(a)) {
return false;
}
}
return true;
}
/**
* Compare the elements of two lists one by one.
*
* @deprecated use {@link #eqObj(Object, Object)} or {@link java.util.List#equals(Object)}
*/
public static boolean eqListSorted(List as, List bs) {
if (as != null && bs != null && as.size() == bs.size()) {
final Iterator asi = as.iterator();
final Iterator bsi = bs.iterator();
while (asi.hasNext() && bsi.hasNext()) {
if (!asi.next().equals(bsi.next()))
return false;
}
return true;
} else {
return eqObj(as, bs);
}
}
/**
* Compare two maps.
*
* @deprecated use {@link #eqObj(Object, Object)} or {@link java.util.Map#equals(Object)}
*/
public static boolean eqMap(Map as, Map bs) {
for (Map.Entry ae : as.entrySet()) {
final Object bv = bs.get(ae.getKey());
if (bv == null || !eqObj(ae.getValue(), bv))
return false;
}
return true;
}
public static boolean bothNotNull(Object a, Object b) {
return a != null && b != null;
}
/**
* Create a hash code for a list of objects. Each of them may be null.
* Algorithm adapted from "Programming in Scala, Second Edition", p670.
*/
@Deprecated
public static int hash(Object... as) {
return Objects.hash(as);
}
}