Pair.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.commons.lang;

/** @author andrew00x */
public final class Pair<A, B> {

    public static <K, V> Pair<K, V> of(K k, V v) {
        return new Pair<>(k, v);
    }

    public final A first;
    public final B second;

    private final int hashCode;

    public Pair(A first, B second) {
        this.first = first;
        this.second = second;
        int hashCode = 7;
        hashCode = hashCode * 31 + (first == null ? 0 : first.hashCode());
        hashCode = hashCode * 31 + (second == null ? 0 : second.hashCode());
        this.hashCode = hashCode;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof Pair<?, ?>)) {
            return false;
        }
        final Pair other = (Pair)o;
        return (first == null ? other.first == null : first.equals(other.first)) &&
               (second == null ? other.second == null : second.equals(other.second));
    }

    @Override
    public int hashCode() {
        return hashCode;
    }

    @Override
    public String toString() {
        return "{first=" + first + ", second=" + second + '}';
    }
}