478 lines
19 KiB
Java
478 lines
19 KiB
Java
/*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership.
|
|
* The ASF licenses this file to You under the Apache License, Version 2.0
|
|
* (the "License"); you may not use this file except in compliance with
|
|
* the License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
package org.apache.commons.lang3;
|
|
|
|
import java.util.Random;
|
|
|
|
/**
|
|
* <p>Generates random {@code String}s.</p>
|
|
*
|
|
* <p><b>Caveat: Instances of {@link Random}, upon which the implementation of this
|
|
* class relies, are not cryptographically secure.</b></p>
|
|
*
|
|
* <p>RandomStringUtils is intended for simple use cases. For more advanced
|
|
* use cases consider using Apache Commons Text's
|
|
* <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/RandomStringGenerator.html">
|
|
* RandomStringGenerator</a> instead.</p>
|
|
*
|
|
* <p>The Apache Commons project provides
|
|
* <a href="https://commons.apache.org/rng">Commons RNG</a> dedicated to pseudo-random number generation, that may be
|
|
* a better choice for applications with more stringent requirements
|
|
* (performance and/or correctness).</p>
|
|
*
|
|
* <p>Note that <em>private high surrogate</em> characters are ignored.
|
|
* These are Unicode characters that fall between the values 56192 (db80)
|
|
* and 56319 (dbff) as we don't know how to handle them.
|
|
* High and low surrogates are correctly dealt with - that is if a
|
|
* high surrogate is randomly chosen, 55296 (d800) to 56191 (db7f)
|
|
* then it is followed by a low surrogate. If a low surrogate is chosen,
|
|
* 56320 (dc00) to 57343 (dfff) then it is placed after a randomly
|
|
* chosen high surrogate.</p>
|
|
*
|
|
* <p>#ThreadSafe#</p>
|
|
* @since 1.0
|
|
*/
|
|
public class RandomStringUtils {
|
|
|
|
/**
|
|
* <p>Random object used by random method. This has to be not local
|
|
* to the random method so as to not return the same value in the
|
|
* same millisecond.</p>
|
|
*/
|
|
private static final Random RANDOM = new Random();
|
|
|
|
/**
|
|
* <p>{@code RandomStringUtils} instances should NOT be constructed in
|
|
* standard programming. Instead, the class should be used as
|
|
* {@code RandomStringUtils.random(5);}.</p>
|
|
*
|
|
* <p>This constructor is public to permit tools that require a JavaBean instance
|
|
* to operate.</p>
|
|
*/
|
|
public RandomStringUtils() {
|
|
}
|
|
|
|
// Random
|
|
//-----------------------------------------------------------------------
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of all characters.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
*/
|
|
public static String random(final int count) {
|
|
return random(count, false, false);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of characters whose
|
|
* ASCII value is between {@code 32} and {@code 126} (inclusive).</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
*/
|
|
public static String randomAscii(final int count) {
|
|
return random(count, 32, 127, false, false);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is between the inclusive minimum and
|
|
* the exclusive maximum.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of characters whose
|
|
* ASCII value is between {@code 32} and {@code 126} (inclusive).</p>
|
|
*
|
|
* @param minLengthInclusive the inclusive minimum length of the string to generate
|
|
* @param maxLengthExclusive the exclusive maximum length of the string to generate
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomAscii(final int minLengthInclusive, final int maxLengthExclusive) {
|
|
return randomAscii(RandomUtils.nextInt(minLengthInclusive, maxLengthExclusive));
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of Latin alphabetic
|
|
* characters (a-z, A-Z).</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
*/
|
|
public static String randomAlphabetic(final int count) {
|
|
return random(count, true, false);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is between the inclusive minimum and
|
|
* the exclusive maximum.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of Latin alphabetic characters (a-z, A-Z).</p>
|
|
*
|
|
* @param minLengthInclusive the inclusive minimum length of the string to generate
|
|
* @param maxLengthExclusive the exclusive maximum length of the string to generate
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomAlphabetic(final int minLengthInclusive, final int maxLengthExclusive) {
|
|
return randomAlphabetic(RandomUtils.nextInt(minLengthInclusive, maxLengthExclusive));
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of Latin alphabetic
|
|
* characters (a-z, A-Z) and the digits 0-9.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
*/
|
|
public static String randomAlphanumeric(final int count) {
|
|
return random(count, true, true);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is between the inclusive minimum and
|
|
* the exclusive maximum.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of Latin alphabetic
|
|
* characters (a-z, A-Z) and the digits 0-9.</p>
|
|
*
|
|
* @param minLengthInclusive the inclusive minimum length of the string to generate
|
|
* @param maxLengthExclusive the exclusive maximum length of the string to generate
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomAlphanumeric(final int minLengthInclusive, final int maxLengthExclusive) {
|
|
return randomAlphanumeric(RandomUtils.nextInt(minLengthInclusive, maxLengthExclusive));
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of characters which match the POSIX [:graph:]
|
|
* regular expression character class. This class contains all visible ASCII characters
|
|
* (i.e. anything except spaces and control characters).</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomGraph(final int count) {
|
|
return random(count, 33, 126, false, false);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is between the inclusive minimum and
|
|
* the exclusive maximum.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of \p{Graph} characters.</p>
|
|
*
|
|
* @param minLengthInclusive the inclusive minimum length of the string to generate
|
|
* @param maxLengthExclusive the exclusive maximum length of the string to generate
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomGraph(final int minLengthInclusive, final int maxLengthExclusive) {
|
|
return randomGraph(RandomUtils.nextInt(minLengthInclusive, maxLengthExclusive));
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of numeric
|
|
* characters.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
*/
|
|
public static String randomNumeric(final int count) {
|
|
return random(count, false, true);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is between the inclusive minimum and
|
|
* the exclusive maximum.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of \p{Digit} characters.</p>
|
|
*
|
|
* @param minLengthInclusive the inclusive minimum length of the string to generate
|
|
* @param maxLengthExclusive the exclusive maximum length of the string to generate
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomNumeric(final int minLengthInclusive, final int maxLengthExclusive) {
|
|
return randomNumeric(RandomUtils.nextInt(minLengthInclusive, maxLengthExclusive));
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of characters which match the POSIX [:print:]
|
|
* regular expression character class. This class includes all visible ASCII characters and spaces
|
|
* (i.e. anything except control characters).</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomPrint(final int count) {
|
|
return random(count, 32, 126, false, false);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is between the inclusive minimum and
|
|
* the exclusive maximum.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of \p{Print} characters.</p>
|
|
*
|
|
* @param minLengthInclusive the inclusive minimum length of the string to generate
|
|
* @param maxLengthExclusive the exclusive maximum length of the string to generate
|
|
* @return the random string
|
|
* @since 3.5
|
|
*/
|
|
public static String randomPrint(final int minLengthInclusive, final int maxLengthExclusive) {
|
|
return randomPrint(RandomUtils.nextInt(minLengthInclusive, maxLengthExclusive));
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of alpha-numeric
|
|
* characters as indicated by the arguments.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @param letters if {@code true}, generated string may include
|
|
* alphabetic characters
|
|
* @param numbers if {@code true}, generated string may include
|
|
* numeric characters
|
|
* @return the random string
|
|
*/
|
|
public static String random(final int count, final boolean letters, final boolean numbers) {
|
|
return random(count, 0, 0, letters, numbers);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of alpha-numeric
|
|
* characters as indicated by the arguments.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @param start the position in set of chars to start at
|
|
* @param end the position in set of chars to end before
|
|
* @param letters if {@code true}, generated string may include
|
|
* alphabetic characters
|
|
* @param numbers if {@code true}, generated string may include
|
|
* numeric characters
|
|
* @return the random string
|
|
*/
|
|
public static String random(final int count, final int start, final int end, final boolean letters, final boolean numbers) {
|
|
return random(count, start, end, letters, numbers, null, RANDOM);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string based on a variety of options, using
|
|
* default source of randomness.</p>
|
|
*
|
|
* <p>This method has exactly the same semantics as
|
|
* {@link #random(int,int,int,boolean,boolean,char[],Random)}, but
|
|
* instead of using an externally supplied source of randomness, it uses
|
|
* the internal static {@link Random} instance.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @param start the position in set of chars to start at
|
|
* @param end the position in set of chars to end before
|
|
* @param letters if {@code true}, generated string may include
|
|
* alphabetic characters
|
|
* @param numbers if {@code true}, generated string may include
|
|
* numeric characters
|
|
* @param chars the set of chars to choose randoms from.
|
|
* If {@code null}, then it will use the set of all chars.
|
|
* @return the random string
|
|
* @throws ArrayIndexOutOfBoundsException if there are not
|
|
* {@code (end - start) + 1} characters in the set array.
|
|
*/
|
|
public static String random(final int count, final int start, final int end, final boolean letters, final boolean numbers, final char... chars) {
|
|
return random(count, start, end, letters, numbers, chars, RANDOM);
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string based on a variety of options, using
|
|
* supplied source of randomness.</p>
|
|
*
|
|
* <p>If start and end are both {@code 0}, start and end are set
|
|
* to {@code ' '} and {@code 'z'}, the ASCII printable
|
|
* characters, will be used, unless letters and numbers are both
|
|
* {@code false}, in which case, start and end are set to
|
|
* {@code 0} and {@link Character#MAX_CODE_POINT}.
|
|
*
|
|
* <p>If set is not {@code null}, characters between start and
|
|
* end are chosen.</p>
|
|
*
|
|
* <p>This method accepts a user-supplied {@link Random}
|
|
* instance to use as a source of randomness. By seeding a single
|
|
* {@link Random} instance with a fixed seed and using it for each call,
|
|
* the same random sequence of strings can be generated repeatedly
|
|
* and predictably.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @param start the position in set of chars to start at (inclusive)
|
|
* @param end the position in set of chars to end before (exclusive)
|
|
* @param letters if {@code true}, generated string may include
|
|
* alphabetic characters
|
|
* @param numbers if {@code true}, generated string may include
|
|
* numeric characters
|
|
* @param chars the set of chars to choose randoms from, must not be empty.
|
|
* If {@code null}, then it will use the set of all chars.
|
|
* @param random a source of randomness.
|
|
* @return the random string
|
|
* @throws ArrayIndexOutOfBoundsException if there are not
|
|
* {@code (end - start) + 1} characters in the set array.
|
|
* @throws IllegalArgumentException if {@code count} < 0 or the provided chars array is empty.
|
|
* @since 2.0
|
|
*/
|
|
public static String random(int count, int start, int end, final boolean letters, final boolean numbers,
|
|
final char[] chars, final Random random) {
|
|
if (count == 0) {
|
|
return StringUtils.EMPTY;
|
|
} else if (count < 0) {
|
|
throw new IllegalArgumentException("Requested random string length " + count + " is less than 0.");
|
|
}
|
|
if (chars != null && chars.length == 0) {
|
|
throw new IllegalArgumentException("The chars array must not be empty");
|
|
}
|
|
|
|
if (start == 0 && end == 0) {
|
|
if (chars != null) {
|
|
end = chars.length;
|
|
} else if (!letters && !numbers) {
|
|
end = Character.MAX_CODE_POINT;
|
|
} else {
|
|
end = 'z' + 1;
|
|
start = ' ';
|
|
}
|
|
} else if (end <= start) {
|
|
throw new IllegalArgumentException("Parameter end (" + end + ") must be greater than start (" + start + ")");
|
|
}
|
|
|
|
final int zero_digit_ascii = 48;
|
|
final int first_letter_ascii = 65;
|
|
|
|
if (chars == null && (numbers && end <= zero_digit_ascii
|
|
|| letters && end <= first_letter_ascii)) {
|
|
throw new IllegalArgumentException("Parameter end (" + end + ") must be greater then (" + zero_digit_ascii + ") for generating digits " +
|
|
"or greater then (" + first_letter_ascii + ") for generating letters.");
|
|
}
|
|
|
|
final StringBuilder builder = new StringBuilder(count);
|
|
final int gap = end - start;
|
|
|
|
while (count-- != 0) {
|
|
final int codePoint;
|
|
if (chars == null) {
|
|
codePoint = random.nextInt(gap) + start;
|
|
|
|
switch (Character.getType(codePoint)) {
|
|
case Character.UNASSIGNED:
|
|
case Character.PRIVATE_USE:
|
|
case Character.SURROGATE:
|
|
count++;
|
|
continue;
|
|
}
|
|
|
|
} else {
|
|
codePoint = chars[random.nextInt(gap) + start];
|
|
}
|
|
|
|
final int numberOfChars = Character.charCount(codePoint);
|
|
if (count == 0 && numberOfChars > 1) {
|
|
count++;
|
|
continue;
|
|
}
|
|
|
|
if (letters && Character.isLetter(codePoint)
|
|
|| numbers && Character.isDigit(codePoint)
|
|
|| !letters && !numbers) {
|
|
builder.appendCodePoint(codePoint);
|
|
|
|
if (numberOfChars == 2) {
|
|
count--;
|
|
}
|
|
|
|
} else {
|
|
count++;
|
|
}
|
|
}
|
|
return builder.toString();
|
|
}
|
|
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of characters
|
|
* specified by the string, must not be empty.
|
|
* If null, the set of all characters is used.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @param chars the String containing the set of characters to use,
|
|
* may be null, but must not be empty
|
|
* @return the random string
|
|
* @throws IllegalArgumentException if {@code count} < 0 or the string is empty.
|
|
*/
|
|
public static String random(final int count, final String chars) {
|
|
if (chars == null) {
|
|
return random(count, 0, 0, false, false, null, RANDOM);
|
|
}
|
|
return random(count, chars.toCharArray());
|
|
}
|
|
|
|
/**
|
|
* <p>Creates a random string whose length is the number of characters
|
|
* specified.</p>
|
|
*
|
|
* <p>Characters will be chosen from the set of characters specified.</p>
|
|
*
|
|
* @param count the length of random string to create
|
|
* @param chars the character array containing the set of characters to use,
|
|
* may be null
|
|
* @return the random string
|
|
* @throws IllegalArgumentException if {@code count} < 0.
|
|
*/
|
|
public static String random(final int count, final char... chars) {
|
|
if (chars == null) {
|
|
return random(count, 0, 0, false, false, null, RANDOM);
|
|
}
|
|
return random(count, 0, chars.length, false, false, chars, RANDOM);
|
|
}
|
|
|
|
}
|