CODE EXAMPLE FOR JAVA

java string to long

public class Example {
   public static void main(String[] args)
   {
       String str = "11111";
       String str2 = "88888";
       //Conversion using valueOf(String) method
       long num = Long.valueOf(str);
       long num2 = Long.valueOf(str2);
       System.out.println(num+num2);		
   }
}
Output:
99999