Application Improvements - Beginning Java with WebSphere - page 235

So, we will move the gross salary calculation from EnterEmpInfo into Employee where it belongs. In addition, we
will create new methods to return the information as formatted strings.

1. In Employee, add the following import statement:

import java.text.NumberFormat;

2. In Employee at the end of the class variable definitions, add the following statement to

create a currency formatter object called cf:

NumberFormat cf = NumberFormat.getCurrencyInstance();

3. In Employee, after the fedTaxCalc method, create a new method called

fedTaxCalcFormatted as follows:

public String fedTaxCalcFormatted( double payRate, int exemptions) {
String taxAmt = new String();
taxAmt = cf.format( this .fedTaxCalc(payRate, exemptions));
return taxAmt;
}

Notice that this method doesn't duplicate the fedTaxCalc function. Rather, it uses the fedTaxCalc method to
perform the tax calculation and then simply formats the result. We need to change EnterEmpInfo to call this new
method and use the returned string.

4. In EnterEmpInfo, at the beginning of the actionPerformed method, enter the following

statement to create a string called stringTaxAmt that will hold the formatted tax amount:

String stringTaxAmt = new String();

5. In EnterEmpInfo's actionPerformed method, change the following statement:

double doubleTaxAmt =
emp.fedTaxCalc(doubleEmpPR, intExmp);

to:

stringTaxAmt =
emp.fedTaxCalcFormatted(doubleEmpPR, intExmp);

6. In EnterEmpInfo's actionPerformed method, change the following statement:

resultLbl.setText("The Federal Tax amount is: $" +
doubleTaxAmt + "0");

to:

resultLbl.setText("The Federal Tax amount is: " +
stringTaxAmt);