Java Generate Password and OTP

Generate password and otp in java. To generate a strong password containing upper case, lower case, numbers and special symbols we are going to use the random() method of java.util.random class. For generating a 6 digit OTP also we are going to do the same. Examples of generating password and otp in java is given below.

Java Generate Password and OTP

OTP Generation in Java

How do you generate a 6 digit OTP (One Time Password) in java?

Generating a OTP is very much like generating a password but only difference is that it is numeric only. And moreover generating a six (6) digit OTP is just having length of OTP as 6 digits wide.

Most of the websites need otp generation nowadays for various reasons. One of the main reason is that if you forget your password you can just put your mobile number and get otp and set new password.

So if you are such website owner and need the java code to do the work automatically here is the java code to generate otp and password in just seconds.

Java Program to Generate a 6 Digit OTP

import java.util.*; 
  
public class Generate_OTP_Java { 
 
 // static method to generate OTP
    static char[] OTP_Generate(int len) 
    { 
        System.out.println("Generating OTP using random() : "); 
        System.out.print("You OTP is : "); 
  
        // Using numeric values 
        String numbers = "0123456789"; 
  
        // Using random method 
        Random rdm_method = new Random();
        
        // to store the OTP
        char[] OTP = new char[len]; 
  
        for(int i = 0; i < len; i++) 
        { 
            // Use of charAt() method to get character value 
            // Use of nextInt() as it is scanning the value as int 
            OTP [i] = numbers.charAt(rdm_method.nextInt(numbers.length())); 
        }
        return OTP;
    }
    
    public static void main(String[] args) 
    { 
     // set the desired length to generate a OTP of
        int OTPLength = 6;
        System.out.println(OTP_Generate(OTPLength)); 
    } 
}

/* Output of above code:-

Generating OTP using random() : 
You OTP is : 458312

*/

Generate Password in Java

import java.util.*; 
  
public class Generate_Password_Java
{ 
    public static void main(String[] args) {
        // let the length of password be 10 characters
        int length = 10; 
        System.out.println(Generate_Password(length)); 
    }

    // static method to generate password
    // it is static so that we can 
    // execute it without creating any objects
    static char[] Generate_Password(int len) 
    { 
        System.out.println("Generating New Password using random() : "); 
        System.out.print("Your New Password is : "); 
  
        // Our password must contain all 
        // type of characters lower, upper and special case and numbers
        String lowerChars = "abcdefghijklmnopqrstuvwxyz";
        String capitalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";  
        String symbols = "!@#$%^&*_=+-/.?<>)";
        String numbers = "0123456789";
  
        String values = lowerChars + capitalChars + 
                        numbers + symbols; 
  
        // Using random() method
        Random rdm_method = new Random(); 
  
        // to store our final password
        char[] password = new char[len]; 
  
        for(int i = 0; i < len; i++) 
        { 
            // Use of charAt() method to get character value 
            // Use of nextInt() as we are scanning the value as int 
            password[i] = values.charAt(rdm_method.nextInt(values.length())); 
  
        }

        return password; 
    } 
}

/* Output of above code:-

Generating New Password using random() : 
Your New Password is : Y)EUpL%ITS

*/

You can modify the program by performing variations in like changing the length of password or removing the special symbols or changing the combination. Can you do it
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