org.apache.commons.collections.comparators.BooleanComparator Maven / Gradle / Ivy
Show all versions of aem-sdk-api Show documentation
/*
* 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.collections.comparators;
import java.io.Serializable;
import java.util.Comparator;
/**
* A {@link Comparator} for {@link Boolean} objects that can sort either
* true or false first.
*
* @see #getTrueFirstComparator()
* @see #getFalseFirstComparator()
* @see #getBooleanComparator(boolean)
*
* @since Commons Collections 3.0
* @version $Revision$ $Date$
*
* @author Rodney Waldhoff
*
* @deprecated Apache Commons Collections version 3.x is being deprecated from AEMaaCS. The upgraded version 4.4 of Commons Collections is already included as replacement. Customers are advised to upgrade to this version of the library. Please note: the package name was changed to org.apache.commons.collections4. Further note that there are AEM APIs currently exposing the old collections classes; these will be updated in upcoming releases.
*/
@Deprecated(since = "2021-04-30")
public final class BooleanComparator implements Comparator, Serializable {
/**
* Serialization version.
*/
private static final long serialVersionUID = 1830042991606340609L;
/**
* Constant "true first" reference.
*/
private static final BooleanComparator TRUE_FIRST = new BooleanComparator(true);
/**
* Constant "false first" reference.
*/
private static final BooleanComparator FALSE_FIRST = new BooleanComparator(false);
/**
* true iff true values sort before false values.
*/
private boolean trueFirst = false;
// -----------------------------------------------------------------------
/**
* Returns a BooleanComparator instance that sorts
* true values before false values.
*
* Clients are encouraged to use the value returned from
* this method instead of constructing a new instance
* to reduce allocation and garbage collection overhead when
* multiple BooleanComparators may be used in the same
* virtual machine.
*
* @return the true first singleton BooleanComparator
*/
public static BooleanComparator getTrueFirstComparator() {
return TRUE_FIRST;
}
/**
* Returns a BooleanComparator instance that sorts
* false values before true values.
*
* Clients are encouraged to use the value returned from
* this method instead of constructing a new instance
* to reduce allocation and garbage collection overhead when
* multiple BooleanComparators may be used in the same
* virtual machine.
*
* @return the false first singleton BooleanComparator
*/
public static BooleanComparator getFalseFirstComparator() {
return FALSE_FIRST;
}
/**
* Returns a BooleanComparator instance that sorts
* trueFirst values before
* !trueFirst values.
*
* Clients are encouraged to use the value returned from
* this method instead of constructing a new instance
* to reduce allocation and garbage collection overhead when
* multiple BooleanComparators may be used in the same
* virtual machine.
*
* @param trueFirst when true, sort
* true Booleans before false
* @return a singleton BooleanComparator instance
*/
public static BooleanComparator getBooleanComparator(boolean trueFirst) {
return trueFirst ? TRUE_FIRST : FALSE_FIRST;
}
// -----------------------------------------------------------------------
/**
* Creates a BooleanComparator that sorts
* false values before true values.
*
* Equivalent to {@link #BooleanComparator(boolean) BooleanComparator(false)}.
*
* Please use the static factory instead whenever possible.
*/
public BooleanComparator() {
this(false);
}
/**
* Creates a BooleanComparator that sorts
* trueFirst values before
* !trueFirst values.
*
* Please use the static factories instead whenever possible.
*
* @param trueFirst when true, sort
* true boolean values before false
*/
public BooleanComparator(boolean trueFirst) {
this.trueFirst = trueFirst;
}
// -----------------------------------------------------------------------
/**
* Compares two arbitrary Objects.
* When both arguments are Boolean, this method is equivalent to
* {@link #compare(Boolean,Boolean) compare((Boolean)obj1,(Boolean)obj2)}.
* When either argument is not a Boolean, this methods throws
* a {@link ClassCastException}.
*
* @param obj1 the first object to compare
* @param obj2 the second object to compare
* @return negative if obj1 is less, positive if greater, zero if equal
* @throws ClassCastException when either argument is not Boolean
*/
public int compare(Object obj1, Object obj2) {
return compare((Boolean) obj1, (Boolean) obj2);
}
/**
* Compares two non-null Boolean objects
* according to the value of {@link #sortsTrueFirst()}.
*
* @param b1 the first boolean to compare
* @param b2 the second boolean to compare
* @return negative if obj1 is less, positive if greater, zero if equal
* @throws NullPointerException when either argument null
*/
public int compare(Boolean b1, Boolean b2) {
boolean v1 = b1.booleanValue();
boolean v2 = b2.booleanValue();
return (v1 ^ v2) ? ((v1 ^ trueFirst) ? 1 : -1) : 0;
}
// -----------------------------------------------------------------------
/**
* Implement a hash code for this comparator that is consistent with
* {@link #equals(Object) equals}.
*
* @return a hash code for this comparator.
*/
public int hashCode() {
int hash = "BooleanComparator".hashCode();
return trueFirst ? -1 * hash : hash;
}
/**
* Returns true iff that Object is
* is a {@link Comparator} whose ordering is known to be
* equivalent to mine.
*
* This implementation returns true
* iff that is a {@link BooleanComparator}
* whose value of {@link #sortsTrueFirst()} is equal to mine.
*
* @param object the object to compare to
* @return true if equal
*/
public boolean equals(Object object) {
return (this == object) || ((object instanceof BooleanComparator) && (this.trueFirst == ((BooleanComparator) object).trueFirst));
}
// -----------------------------------------------------------------------
/**
* Returns true iff
* I sort true values before
* false values. In other words,
* returns true iff
* {@link #compare(Boolean,Boolean) compare(Boolean.FALSE,Boolean.TRUE)}
* returns a positive value.
*
* @return the trueFirst flag
*/
public boolean sortsTrueFirst() {
return trueFirst;
}
}