Hello Friend,

1)Fibonacci series:

import java.util.*;

public class Fibonacci {
public static void main(String[] args) throws Exception {
Scanner input=new Scanner(System.in);
System.out.print("Enter value of n: ");
    int num = input.nextInt();
    int f1=0,f2=0,f3=1;
    for(int i=1;i<=num;i++){
        System.out.println(f3);
        f1=f2;
        f2=f3;
        f3=f1+f2;
    }
}
}

2)Check Prime Number

import java.util.*;

class  CheckPrimeNumber
{
    static boolean isPrime(int number){
          boolean isPrime=false;
          int i=(int) Math.ceil(Math.sqrt(number));
          while (i>1){
             if ((number!=i) && (number%i==0)){
                isPrime=false;
                break;
             }
             else if (!isPrime)
             isPrime=true;
             --i;
          }
          return isPrime;
       }
    public static void main(String[] args) 
    {
        Scanner input=new Scanner(System.in);
        System.out.println("Enter Number:");
        int num=input.nextInt();
        if(isPrime(num)){
            System.out.println("Number is Prime!");
        }
        else{
            System.out.println("Number is not prime!");
        }
    }
}

Thanks