public static void main(String[] args)throws NumberFormatException{
        int i=0,a=0,b=1,convert;
        while(i<args.length){
            convert=Integer.parseInt(args[i]);
            a+= convert;
            b*= convert;
            i++;
        }
        System.out.print("Сумма: "+a+"\nПроизведение: "+b);
    }
}

import java.math.BigInteger;
 
public class BigInt {
        
        /**
         * @param args
         */
        public static void main(String[] args) {
                // TODO Auto-generated method stub
                  BigInteger sum = BigInteger.ZERO;
                  BigInteger mul = BigInteger.ONE;
                  for (int i=0;i<args.length;i++) {
                    BigInteger currentNumber = new BigInteger(args[i]);
                    sum = sum.add(currentNumber);
                    mul = mul.multiply(currentNumber);
                  }
                  System.out.println(sum);
                  System.out.println(mul);
        }
}