how to compare uppercase and lowercase in java code example

Example 1: write a program to check whether the character is in lowercase or uppercase in java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Alphabet_Check {
    public static void main(String args[]) throws IOException{
        char m;
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        System.out.print("Enter any alphabet:");
        m = (char) bf.read();
        if(m >= 97 && m <= 123){
            System.out.println("Lower Case");
        }
        else if(m >= 65 && m <= 96){
            System.out.println("Upper Case");
        }
        else if(m >= 48 && m <= 57){
            System.out.println("Digit");
        }
    }
}

Example 2: java lower case to upper case

toUpperCase()