    001/* ===========================================================
    002 * Orson Charts : a 3D chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
    006 *
    007 * http://www.object-refinery.com/orsoncharts/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 * Orson Charts home page:
    028 *
    029 * http://www.object-refinery.com/orsoncharts/index.html
    030 *
    031 */
    032
    033package com.orsoncharts.util;
    034
    035/**
    036 * Utility methods for argument checking.  Throughout Orson Charts, arguments
    037 * passed to methods are validated and exceptions thrown for invalid cases
    038 * (the idea is to fail fast, which usually helps when tracking down errors
    039 * in programming logic).
    040 */
    041public final class ArgChecks {
    042
    043    private ArgChecks() {
    044        // no need to instantiate this ever
    045    }
    046
    047    /**
    048     * Checks if the specified argument is {@code null} and, if it is,
    049     * throws an {@code IllegalArgumentException}.
    050     *
    051     * @param arg  the argument to check ({@code null} permitted).
    052     * @param name  the parameter name ({@code null} not permitted).
    053     */
    054    public static void nullNotPermitted(Object arg, String name) {
    055        if (arg == null) {
    056            throw new IllegalArgumentException("Null '" + name + "' argument.");
    057        }
    058    }
    059
    060    /**
    061     * Checks if the specified argument is negative and, if it is, throws an
    062     * {@code IllegalArgumentException}.
    063     *
    064     * @param value  the value.
    065     * @param name  the parameter name ({@code null} not permitted).
    066     */
    067    public static void negativeNotPermitted(double value, String name) {
    068        if (value < 0.0) {
    069            throw new IllegalArgumentException("Param '" + name
    070                    + "' cannot be negative");
    071        }
    072    }
    073
    074    /**
    075     * Checks if the specified argument is positive and, if it is NOT, throws an
    076     * {@code IllegalArgumentException}.
    077     *
    078     * @param value  the value.
    079     * @param name  the parameter name ({@code null} not permitted).
    080     */
    081    public static void positiveRequired(double value, String name) {
    082        if (value <= 0.0) {
    083            throw new IllegalArgumentException("Param '" + name
    084                    + "' must be positive.");
    085        }
    086    }
    087
    088    /**
    089     * Checks if the specified argument is finite and, if it is NOT, throws an
    090     * {@code IllegalArgumentException}.
    091     *
    092     * @param value  the value.
    093     * @param name  the parameter name ({@code null} not permitted).
    094     *
    095     * @since 1.4
    096     */
    097    public static void finiteRequired(double value, String name) {
    098        if (Double.isInfinite(value)) {
    099            throw new IllegalArgumentException("Param '" + name
    100                    + "' must be finite.");
    101        }
    102    }
    103
    104    /**
    105     * Checks if the specified argument is finite and positive and,
    106     * if it is NOT, throws an {@code IllegalArgumentException}.
    107     *
    108     * @param value  the value.
    109     * @param name  the parameter name ({@code null} not permitted).
    110     *
    111     * @since 1.4
    112     */
    113    public static void finitePositiveRequired(double value, String name) {
    114        if (value <= 0.0 || Double.isInfinite(value)) {
    115            throw new IllegalArgumentException("Param '" + name
    116                    + "' must be finite and positive.");
    117        }
    118    }
    119
    120    /**
    121     * Checks that the index is less than the specified {@code arrayLimit}
    122     * and throws an {@code IllegalArgumentException} if it is not.
    123     *
    124     * @param index  the array index.
    125     * @param name  the parameter name (to display in the error message).
    126     * @param arrayLimit  the array size.
    127     */
    128    public static void checkArrayBounds(int index, String name,
    129            int arrayLimit) {
    130        if (index >= arrayLimit) {
    131            throw new IllegalArgumentException("Requires '" + name
    132                    + "' in the range 0 to " + (arrayLimit - 1));
    133        }
    134    }
    135
    136}