NumericTypeComparator.java

/*******************************************************************************
 * Copyright (c) 2011, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation
 *
 ******************************************************************************/
package org.eclipse.persistence.internal.jpa.jpql;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Comparator;

/**
 * This {@link Comparator} compares two {@link Class} values and returned the appropriate numeric
 * type that takes precedence.
 *
 * @since 2.4
 * @since 2.5
 * @author Pascal Filion
 */
final class NumericTypeComparator implements Comparator<Class<?>> {

    /**
     * The singleton instance of this {@link NumericTypeComparator}.
     */
    private static final Comparator<Class<?>> INSTANCE = new NumericTypeComparator();

    /**
     * Creates a new <code>NumericTypeComparator</code>.
     */
    private NumericTypeComparator() {
        super();
    }

    /**
     * Returns the singleton instance of this {@link NumericTypeComparator}.
     *
     * @return The singleton instance of this {@link NumericTypeComparator}
     */
    public static Comparator<Class<?>> instance() {
        return INSTANCE;
    }

    /**
     * {@inheritDoc}
     */
    public int compare(Class<?> type1, Class<?> type2) {

        // Same type
        if (type1 == type2) {
            return 0;
        }

        // Object type
        if (type1 == Object.class) return -1;
        if (type2 == Object.class) return  1;

        // Double
        if (type1 == Double.TYPE || type1 == Double.class) return -1;
        if (type2 == Double.TYPE || type2 == Double.class) return  1;

        // Float
        if (type1 == Float.TYPE || type1 == Float.class) return -1;
        if (type2 == Float.TYPE || type2 == Float.class) return  1;

        // BigDecimal
        if (type1 == BigDecimal.class) return -1;
        if (type2 == BigDecimal.class) return  1;

        // BigInteger
        if (type1 == BigInteger.class) return -1;
        if (type2 == BigInteger.class) return  1;

        // Long
        if (type1 == Long.TYPE || type1 == Long.class) return -1;
        if (type2 == Long.TYPE || type2 == Long.class) return  1;

        // Integer
        if (type1 == Integer.TYPE || type1 == Integer.class) return -1;
        if (type2 == Integer.TYPE || type2 == Integer.class) return 1;

        return 1;
    }
}