Method for extracting the numbers from string and applying computation over the extracted numbers. 
The program returns the sum of all the numbers found. 

How to run:
To manually test user can call ADD( STRING ) by passing a string with numbers in it which will return a int value. 

Exceptions: 
Program can throw exception for negative values. Thrown exception will show all the negative values and prgram will terminate itself.

  

Testing:
To run the unit test, execute StrCal7Shifts\src\StringCalculator.java, as test cases are implemeted in that file in test method.