    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.text;
    018
    019import java.util.function.IntUnaryOperator;
    020
    021/**
    022 * TextRandomProvider implementations are used by {@link RandomStringGenerator}
    023 * as a source of randomness.  It is highly recommended that the
    024 * <a href="https://commons.apache.org/proper/commons-rng/">Apache Commons RNG</a>
    025 * library be used to provide the random number generation.
    026 *
    027 * <p>
    028 * {@code TextRandomProvider} is a functional interface and need not be explicitly implemented.
    029 * </p>
    030 * <p>
    031 * For example:
    032 * </p>
    033 * <pre>
    034 * {@code
    035 * UniformRandomProvider rng = RandomSource.create(...);
    036 * RandomStringGenerator gen = RandomStringGenerator.builder()
    037 *     .usingRandom(rng::nextInt)
    038 *     // additional builder calls as needed
    039 *     .build();
    040 * }
    041 * </pre>
    042 * @since 1.1
    043 */
    044public interface TextRandomProvider extends IntUnaryOperator {
    045
    046    /**
    047     * Generates an int value between 0 (inclusive) and the specified value (exclusive).
    048     *
    049     * @param max Bound on the random number to be returned. Must be positive.
    050     * @return a random int value between 0 (inclusive) and max (exclusive).
    051     * @since 1.14.0
    052     */
    053    @Override
    054    default int applyAsInt(final int max) {
    055        return nextInt(max);
    056    }
    057
    058    /**
    059     * Generates an int value between 0 (inclusive) and the specified value (exclusive).
    060     *
    061     * @param max Bound on the random number to be returned. Must be positive.
    062     * @return a random int value between 0 (inclusive) and max (exclusive).
    063     * @deprecated Use {@link #applyAsInt(int)}.
    064     */
    065    @Deprecated
    066    int nextInt(int max);
    067}