troubleshooting Question

Revise to include Exception handling

Avatar of Mike Eghtebas
Mike EghtebasFlag for United States of America asked on
Java
10 Comments1 Solution283 ViewsLast Modified:
Below, there is CalculatorTest.java attached. The error handling in it mostly via some if statements etc.

Question: What is the best way to use java Exception handling routines to improve it?


import java.text.DecimalFormat;

public class CalculatorTest{
    

   public static boolean isNumeric(String s) {

        boolean b = true;

        try {
          float f = Float.parseFloat(s);
        }
        catch(Exception ex){
            b = false;
        }
            return b;
        }

        public static String validData(String [] ss){

            String temp="";

            if(!isNumeric(ss[0])) {
                temp= "Wrong Input: " + ss[0];
            }else if(!isNumeric(ss[2])) {
                temp= "Wrong Input: " + ss[2];
            }else if(Double.parseDouble(ss[2])==0.0 && ss[1].charAt(0)=='/') {
                temp= "Division by zero";
            }
            return temp;
        }

        public static String validInput(String [] ss){

//                 for(String s: ss){
//                System.out.println(s);
//            }

            String temp="";

//            System.out.println("Im here");
            if (ss.length !=3) {
                temp = "Usage: java Calculator operand1 operator operand2\n";

            }else if(!ss[1].equals("+") && !ss[1].equals("-") && !ss[1].equals("*") && !ss[1].equals("/")){
                temp = "Usage: java Calculator operand1 operator operand2\n"+
                       "       (Make sure to have * inside \"*\" as shown here.";}
            return temp;
        }

        public static void main(String[] args) {

//            for(String s: args){
//                System.out.println("|"+s+"|");
//            }

            String errorMessage = validInput(args);

//            System.out.println("Test return: "+errorMessage+"\n");

            if(errorMessage.trim().length() != 0){

                System.out.println(errorMessage+"\n");

            }else{

                errorMessage = validData(args);

                if(errorMessage.trim().length() != 0){
                    System.out.println("Error: " + errorMessage + "\n");
                    
              //  }else if(errorMessage.toString()==""){
                //    System.out.println(errorMessage + "\n");
                }else{
                    printTheCalculationresult(args);
                }
            }
        }

        public static void printTheCalculationresult(String[] args)
        {
            System.out.print("print The Calculation result: ");

            DecimalFormat df=new DecimalFormat("0.##");
            double result=0.0;


            switch (args[1].charAt(0)){
                case '+': result=(int) Double.parseDouble(args[0]) +
                                 (int) Double.parseDouble(args[2]);
                          break;
                case '-': result=(int) Double.parseDouble(args[0]) -
                                 (int) Double.parseDouble(args[2]);
                          break;
                case '*': result=(int)Double.parseDouble(args[0])*
                                 (int) Double.parseDouble(args[2]);
                          break;
                case '/': result=Double.parseDouble(args[0]) /
                                 Double.parseDouble(args[2]);
            }

            System.out.print(args[0]+ " " +    args[1] + " " + args[2] + " = "+  result+"\n\n");
    }
}
ASKER CERTIFIED SOLUTION
Join our community to see this answer!
Unlock 1 Answer and 10 Comments.
Start Free Trial
Learn from the best

Network and collaborate with thousands of CTOs, CISOs, and IT Pros rooting for you and your success.

Andrew Hancock - VMware vExpert
See if this solution works for you by signing up for a 7 day free trial.
Unlock 1 Answer and 10 Comments.
Try for 7 days

”The time we save is the biggest benefit of E-E to our team. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange.

-Mike Kapnisakis, Warner Bros