What is RandomStringUtils.randomAlphanumeric() in Java?

randomAlphanumeric() is a staticthe methods in Java that can be called without creating an object of the class. method of the RandomStringUtils class that is used to generate random strings consisting of alphanumeric characters.

Characters will be chosen from the set of Latin alphabetic characters (a-z, A-Z) and the digits 0-9.

There are two variations to this method.

Variation 1

This variation of the method creates a random string whose length is the number of characters specified.

Syntax

public static String randomAlphanumeric(final int count)

Parameters

final int count: the length of random string to generate.

Return Value

The method returns a random string.

Variation 2

This variation of the method creates a random string whose length is between the inclusive minimum and the exclusive maximum.

Syntax

public static String randomAlphanumeric(final int minLengthInclusive, final int maxLengthExclusive)

Parameters

• final int minLengthInclusive: The inclusive minimum length of the string to generate.

• final int maxLengthExclusive: The exclusive maximum length of the string to generate.

Return value

The method returns a random string.

How to import RandomStringUtils

The definition of RandomStringUtils can be found in the Apache Commons Lang package, which we can add to the Maven project by adding the following dependency to the pom.xml file:

<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
</dependency>

For other versions of the commons-lang package, refer to the Maven Repository.

You can import the RandomStringUtils class as follows.

import org.apache.commons.lang3.RandomStringUtils;

Code

Example 1

• count = 5

In the first example, we use the first variation of the method where we specify the exact length of the generated string.

The method generates the random string qjl3a of length five consisting of only alphabets and digits from $0$ to $9$.

Example 2

• minimum length = 5
• maximum length = 10

In the second example, we use the second variation of the method where we specify the minimum and maximum length of the generated string.

The method generates the random string O1MOG of length six consisting of only alphabets and digits from $0$ to $9$.

Output

The output of the code will be as follows:

The output of RandomStringUtils.randomAlphanumeric when the length is 5 - qjl3a
The output of RandomStringUtils.randomAlphanumeric when the (minlength, maxlength) is (5, 10) - O1MOG

The output might differ when the code above is run every time.