    001/* ===================================================
    002 * JFreeSVG : an SVG library for the Java(tm) platform
    003 * ===================================================
    004 *
    005 * (C)opyright 2013, 2014, by Object Refinery Limited.  All rights reserved.
    006 *
    007 * Project Info:  http://www.jfree.org/jfreesvg/index.html
    008 *
    009 * This program is free software: you can redistribute it and/or modify
    010 * it under the terms of the GNU General Public License as published by
    011 * the Free Software Foundation, either version 3 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This program is distributed in the hope that it will be useful,
    015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
    016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    017 * GNU General Public License for more details.
    018 *
    019 * You should have received a copy of the GNU General Public License
    020 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    021 *
    022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    023 * Other names may be trademarks of their respective owners.]
    024 *
    025 * If you do not wish to be bound by the terms of the GPL, an alternative
    026 * commercial license can be purchased.  For details, please see visit the
    027 * JFreeSVG home page:
    028 *
    029 * http://www.jfree.org/jfreesvg
    030 *
    031 */
    032
    033package org.jfree.graphics2d;
    034
    035/**
    036 * A utility class that performs checks for method argument validity.
    037 */
    038public class Args {
    039
    040    private Args() {
    041        // no need to instantiate this
    042    }
    043
    044    /**
    045     * Checks that an argument is non-<code>null</code> and throws an
    046     * <code>IllegalArgumentException</code> otherwise.
    047     *
    048     * @param obj  the object to check for <code>null</code>.
    049     * @param ref  the text name for the parameter (to include in the exception
    050     *     message).
    051     */
    052    public static void nullNotPermitted(Object obj, String ref) {
    053        if (obj == null) {
    054            throw new IllegalArgumentException("Null '" + ref + "' argument.");
    055        }
    056    }
    057
    058    /**
    059     * Checks an array to ensure it has the correct length and throws an
    060     * <code>IllegalArgumentException</code> if it does not.
    061     *
    062     * @param length  the required length.
    063     * @param array  the array to check.
    064     * @param ref  the text name of the array parameter (to include in the
    065     *     exception message).
    066     */
    067    public static void arrayMustHaveLength(int length, boolean[] array,
    068            String ref) {
    069        nullNotPermitted(array, "array");
    070        if (array.length != length) {
    071            throw new IllegalArgumentException("Array '" + ref
    072                    + "' requires length " + length);
    073        }
    074    }
    075
    076    /**
    077     * Checks an array to ensure it has the correct length and throws an
    078     * <code>IllegalArgumentException</code> if it does not.
    079     *
    080     * @param length  the required length.
    081     * @param array  the array to check.
    082     * @param ref  the text name of the array parameter (to include in the
    083     *     exception message).
    084     */
    085    public static void arrayMustHaveLength(int length, double[] array,
    086            String ref) {
    087        nullNotPermitted(array, "array");
    088        if (array.length != length) {
    089            throw new IllegalArgumentException("Array '" + ref
    090                    + "' requires length " + length);
    091        }
    092    }
    093}