Prime Number Program In java

The following program checks (find) whether a number is prime or not. It also prints all prime numbers between 1 to the number input by user. 

The Program shows output as :

Enter number to check prime : 13
Entered Number is a Prime Number

Prime Number between 1 to 13
2  3  5  7  11  13 
Total Prime Number : 6
// Java Prime Number Program

 import java.util.Scanner;
 class Number
 {

    // Checks if the number is prime or not
    public void primeNumber(int num)
    {
       boolean flag=true;
       
       if(num > 1)
       {
          for(int i=2; i< num/2; i++)
          {
           if(num%i==0)
           {
            flag=false;
             break;
           }
          }
          
          if(flag)
           System.out.println("Entered Number is a Prime Number ");
          else
           System.out.println("Entered Number is Not a Prime Number ");
       }
       else
        System.out.println("Not a Prime Number ");
    }
    
    // Lists or print all prime numbers between 1 to num ( num=100 or any value )

    public void listPrimeNumber(int num)
    {
     boolean flag=true;
     int j, countPrime=0;
     
     System.out.println("Prime number between 1 to " + num);
     for(int i=2; i<=num; i++) 
     {
      for(j=2; j<=i/2; j++)
      {
       if(i%j==0)
       {
        flag=false;
        break;
       }
      }
      
      if(flag)
      {
           countPrime+=1;
       System.out.println(i + "  ");
      }
      else
                {
                  flag = true; 
                }
     }
     
     if(countPrime==0)
        {
          System.out.println("No Prime Number exist ");
        }

     else
        {
          System.out.println("\nTotal Prime Numbers : " + countPrime);
     }
   }

    public static void main(String args[])
    {
          Number prime=new Number();

          int num;
          Scanner input=new Scanner(System.in);
         
          System.out.println("Enter the number to check prime : ");
          num = input.nextInt();
          
          prime.primeNumber(num);
          prime.listPrimeNumber(num);
    }
 }