org.conqat.lib.commons.collections.ImmutablePair Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of teamscale-lib-commons Show documentation
Provides common utility functions
There is a newer version: 2024.7.2
Show newest version
/*
 * Copyright (c) CQSE GmbH
 *
 * 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.conqat.lib.commons.collections;

import java.io.Serializable;

import org.conqat.lib.commons.test.IndexValueClass;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

/**
 * Simple readonly pair class.
 */
@IndexValueClass
public class ImmutablePair implements Cloneable, Comparable>, Serializable {

	/** Version used for serialization. */
	private static final long serialVersionUID = 1;

	protected static final String FIRST_PROPERTY = "first";

	protected static final String SECOND_PROPERTY = "second";

	/** The first element. */
	@JsonProperty(FIRST_PROPERTY)
	protected S first;

	/** The second element. */
	@JsonProperty(SECOND_PROPERTY)
	protected T second;

	/** Constructor. */
	@JsonCreator
	public ImmutablePair(@JsonProperty(FIRST_PROPERTY) S first, @JsonProperty(SECOND_PROPERTY) T second) {
		this.first = first;
		this.second = second;
	}

	/** Copy constructor. */
	public ImmutablePair(ImmutablePair p) {
		this.first = p.first;
		this.second = p.second;
	}

	/** Returns the first element of the pair. */
	public S getFirst() {
		return first;
	}

	/** Returns the second element of the pair. */
	public T getSecond() {
		return second;
	}

	/** {@inheritDoc} */
	@Override
	public boolean equals(Object obj) {
		if (!(obj instanceof ImmutablePair)) {
			return false;
		}
		ImmutablePair p = (ImmutablePair) obj;
		return areEqual(first, p.first) && areEqual(second, p.second);
	}

	/** Returns true if either both are null or they are equal. */
	private static boolean areEqual(Object o1, Object o2) {
		if (o1 == null) {
			return o2 == null;
		}
		return o1.equals(o2);
	}

	/**
	 * {@inheritDoc}
	 * 
	 * The hash code is based on the hash code of the first and second members.
	 */
	@Override
	public int hashCode() {
		int firstCode = 1;
		if (first != null) {
			firstCode = first.hashCode();
		}

		int secondCode = 1;
		if (second != null) {
			secondCode = second.hashCode();
		}

		return firstCode + 1013 * secondCode;
	}

	/** {@inheritDoc} */
	@Override
	public String toString() {
		return "(" + first + "," + second + ")";
	}

	/** {@inheritDoc} */
	@Override
	protected ImmutablePair clone() {
		return new ImmutablePair<>(this);
	}

	/**
	 * {@inheritDoc}
	 * 

	 * Compare based on first element. Use second element only if first elements are equal. Null entries
	 * are sorted to the top.
	 */
	@Override
	public int compareTo(ImmutablePair pair) {
		int cmp = objCompare(first, pair.first);
		if (cmp != 0) {
			return cmp;
		}
		return objCompare(second, pair.second);
	}

	/**
	 * Performs comparison on two arbitrary objects of the same type.
	 */
	@SuppressWarnings("unchecked")
	private static  int objCompare(O o1, O o2) {
		if (o1 == null) {
			if (o2 == null) {
				return 0;
			}
			return -1;
		} else if (o2 == null) {
			return 1;
		}

		if ((o1 instanceof Comparable) && (o2 instanceof Comparable)) {
			try {
				return ((Comparable