Spring Framework example source code file (BooleanComparator.java)

This example Spring Framework source code file (BooleanComparator.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

boolean, boolean, booleancomparator, booleancomparator, comparator, io, object, object, serializable, string, true_high, true_low, true_low, util

The Spring Framework BooleanComparator.java source code

/*
 * Copyright 2002-2005 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.util.comparator;

import java.io.Serializable;
import java.util.Comparator;

/**
 * A Comparator for Boolean objects that can sort either true or false first.
 *
 * @author Keith Donald
 * @since 1.2.2
 */
public final class BooleanComparator implements Comparator, Serializable {

	/**
	 * A shared default instance of this comparator, treating true lower
	 * than false.
	 */
	public static final BooleanComparator TRUE_LOW = new BooleanComparator(true);

	/**
	 * A shared default instance of this comparator, treating true higher
	 * than false.
	 */
	public static final BooleanComparator TRUE_HIGH = new BooleanComparator(false);


	private final boolean trueLow;


	/**
	 * Create a BooleanComparator that sorts boolean values based on
	 * the provided flag.
	 * <p>Alternatively, you can use the default shared instances:
	 * <code>BooleanComparator.TRUE_LOW and
	 * <code>BooleanComparator.TRUE_HIGH.
	 * @param trueLow whether to treat true as lower or higher than false
	 * @see #TRUE_LOW
	 * @see #TRUE_HIGH
	 */
	public BooleanComparator(boolean trueLow) {
		this.trueLow = trueLow;
	}


	public int compare(Object o1, Object o2) {
		boolean v1 = ((Boolean) o1).booleanValue();
		boolean v2 = ((Boolean) o2).booleanValue();
		return (v1 ^ v2) ? ((v1 ^ this.trueLow) ? 1 : -1) : 0;
	}

	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (!(obj instanceof BooleanComparator)) {
			return false;
		}
		return (this.trueLow == ((BooleanComparator) obj).trueLow);
	}

	public int hashCode() {
		return (this.trueLow ? -1 : 1) * getClass().hashCode();
	}

	public String toString() {
		return "BooleanComparator: " + (this.trueLow ? "true low" : "true high");
	}

}