Generate a random character in Java

This post will discuss how to generate a random character in Java.

1. Using `Random.nextInt()` method

If you need to generate a random character between some specific range, you can do so using the nextInt() method from the Random class. The following code generates a random character in the range A-Z. You can easily modify the code to generate a character in the range a-z.

import java.util.Random;

public class Main {

private static char randomChar() {

Random r = new Random();

return (char)(r.nextInt(26) + 'A');

}

public static void main(String[] args) {

char c = randomChar();

System.out.println(c);

}

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If you need to generate values in the ranges a-z and A-Z, you can do something like:

import java.util.Random;

public class Main {

private static char randomChar() {

int rand = new Random().nextInt(52);

char start = (rand < 26) ? 'A' : 'a';

return (char) (start + rand % 26);

}

public static void main(String[] args) {

char c = randomChar();

System.out.println(c);

}

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If you want to generate an alphanumeric random character or use any other specific character set, you can do as follows.

import java.util.Random;

public class Main {

public static void main(String[] args) {

String alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

Random r = new Random();

char c = alphabet.charAt(r.nextInt(alphabet.length()));

System.out.println(c);

}

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2. Using Apache Commons Lang

You could also use the RandomStringUtils class from the Apache Commons Lang library. It offers several methods like randomAlphabetic(), randomAlphanumeric(), randomNumeric(), randomAscii(), etc., to create a random string of specific length.

import org.apache.commons.lang3.RandomStringUtils;

public class Main {

public static void main(String[] args) {

String c = RandomStringUtils.randomAlphabetic(1);

System.out.println(c);

}

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To get the lowercase equivalent, call the toLowerCase() method:

import org.apache.commons.lang3.RandomStringUtils;

public class Main {

public static void main(String[] args) {

String c = RandomStringUtils.randomAlphabetic(1).toLowerCase();

System.out.println(c);

}

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That’s all about generating a random character in Java.

Generate a random character in Java

1. Using Random.nextInt() method

2. Using Apache Commons Lang

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1. Using `Random.nextInt()` method