1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.text;
18
19 import java.util.function.IntUnaryOperator;
20
21 /**
22 * TextRandomProvider implementations are used by {@link RandomStringGenerator}
23 * as a source of randomness. It is highly recommended that the
24 * <a href="https://commons.apache.org/proper/commons-rng/">Apache Commons RNG</a>
25 * library be used to provide the random number generation.
26 *
27 * <p>
28 * {@code TextRandomProvider} is a functional interface and need not be explicitly implemented.
29 * </p>
30 * <p>
31 * For example:
32 * </p>
33 * <pre>
34 * {@code
35 * UniformRandomProvider rng = RandomSource.create(...);
36 * RandomStringGenerator gen = RandomStringGenerator.builder()
37 * .usingRandom(rng::nextInt)
38 * // additional builder calls as needed
39 * .build();
40 * }
41 * </pre>
42 * @since 1.1
43 */
44 public interface TextRandomProvider extends IntUnaryOperator {
45
46 /**
47 * Generates an int value between 0 (inclusive) and the specified value (exclusive).
48 *
49 * @param max Bound on the random number to be returned. Must be positive.
50 * @return a random int value between 0 (inclusive) and max (exclusive).
51 * @since 1.14.0
52 */
53 @Override
54 default int applyAsInt(final int max) {
55 return nextInt(max);
56 }
57
58 /**
59 * Generates an int value between 0 (inclusive) and the specified value (exclusive).
60 *
61 * @param max Bound on the random number to be returned. Must be positive.
62 * @return a random int value between 0 (inclusive) and max (exclusive).
63 * @deprecated Use {@link #applyAsInt(int)}.
64 */
65 @Deprecated
66 int nextInt(int max);
67 }