How to make a generator of random letters and numbers in java?

Question

Java

How to make a generator of random numbers and letters in java?
For example, so that each time, completely random numbers are displayed, and letters, for example 8, or 16, random numbers? and letters?

Answer 1

int length = 16;
Random r = new Random();
String s = r.ints(48, 122)
            .filter(i -> (i < 57 || i > 65) && (i < 90 || i > 97))
            .mapToObj(i -> (char) i)
            .limit(length)
            .collect(StringBuilder::new, StringBuilder::append, StringBuilder::append)
            .toString();

Answer 2

So I think it will be clearer.

import java.util.Random;

char[] array = new char[8];
int rand;
Random r = new Random();
for (int i = 0; i< 8; i++) {
     rand = r.nextInt(127) + 1; //тут менять нужные диапазоны ((max - min) + 1) + min (см ASCII)
     array[i] = (char)rand;
}
for(char c : array) 
     System.out.println(c);
}

ASCII

Answer 3

You can also create an array or a string with all the listed letters and numbers. And already randomly select an element of this array or string.