Java Program to generate random string

We can make use of the String that holds all the characters that can be a part of the random string to be generated and make use of the java.util.Random class to generate the random string based on the length required.

import java.util.Random;

/**
 * Code2care Java Examples
 *
 * Generate Random String
 *
 */
public class JavaRandomStringExample {

    public static void main(String[] args) {
       JavaRandomStringExample jrs = new JavaRandomStringExample();
        System.out.println(jrs.generateRamdonString(15));
        System.out.println(jrs.generateRamdonString(25));
        System.out.println(jrs.generateRamdonString(35));
        System.out.println(jrs.generateRamdonString(45));
    }

    public String generateRamdonString(int size) {
        String digits = "ABCDEFGHIJKLMNOPQRSTUVWZYZabcdefghijklmnopqrstuvwxyz0123456789";
        int sizeOfRandomString = size;
        StringBuilder randomString = new StringBuilder();

        for(int i=1;i<=sizeOfRandomString;i++) {
            Random random = new Random();
            int position = random.nextInt(digits.length());
            randomString = randomString.append(digits.charAt(position));
        }

        return  randomString.toString();
    }
}

7pgxqwiR1TEhZJB
kJexTSwpP6pt6kbTY22LhFxFC
m2kySQF7QLx1JGLR9Kz3CCPHkBFircEE9Jt
esMtxgqWd31UbokPwWqAwqu8sak5aJYTpYyoKdPZYH5q6