如何从文本文件读取，处理和打印数据？

Question

Please I need help with this:

A. Further enhance your payroll program. Add a Boolean method named inputData that has reference parameters to input an employeeName, hourlyRate, hoursWorked, and taxRate from the payroll.txt file. After the statement within the method main that calls the method reportTitle, add a loop that allows the program to read, process, and print information for multiple employees untill all data has been read and processed. The program you write in this exercise does not calculate the grossAmount and netAmount; this will be done in the later exercise. In this program, just assign 0.0 to each of those variables.

To permit the method inputData to read and return an employee name, change the type of the variable employeeName from class String to class StringBuffer; you will have to change the type of the corresponding method parameter in printEmployeeInfo, as well.

The method inputData also needs to read and return values for hourlyRate, hoursWorked, and taxRate. To make this possible, change the types of the variables hourlyRate, hoursWorked, and taxRate from the primitive type double to the class DoubleClass. Defined in the class is a constructor with no parameters that is used to initialize the objects instantiated to 0.0. The method setNum() is used to set the data member of the object using the method' parameter. The method getNum() is used to retrieve the double value stored within the object.

Here's the payroll.txt file:

John Smith

9.45 40 15

Jane Doe

12.50 45 15

Harry Morgan

20.00 40 20

Carmen Martinez 

25.00 35 25

Jacintha Washington 

50.85 60 34

Here's the desired output:

                                  Instructions for Payroll Report Program

    This program calculates a paycheck for each employee.
    A text file containing the following information will be created:
    name, pay rate, hours worked, and tax percentage to be deducted.

    The program will create a report in columnar format showing the empoyee name, hourly rate, number of hours worked, tax rate, gross pay, and net pay.

    After all employees are processed, totals will be displayed, including total gross amount and total net pay.


                                          Payroll Report

    Employee                Hourly          Hours           Tax         Gross           Net
    Name                    Rate            Worked          Rate        Amount          Amount
    --------------------    --------        --------        --------    --------        --------
    John Smith                  9.45           40.00           15.00        0.00            0.00
    Jane Doe                   12.50           45.00           15.00        0.00            0.00
    Harry Morgan               20.00           40.00           20.00        0.00            0.00
    Carmen Martinez            25.00           35.00           25.00        0.00            0.00
    Jacintha Washington        50.85           60.00           34.00        0.00            0.00

Here's my code so far:

public class Payroll3
{
    final float FULL_TIME = 40;
    public static void main(String[] args)
    {
        StringBuffer employeeName;
        DoubleClass hourlyRate, hoursWorked, taxRate, grossAmount, netAmount;
        instructions();
        reportTitle();
        //printEmployeeInfo(employeeName, hourlyRate, hoursWorked, taxRate,   grossAmount, netAmount);
    }
    public static void instructions()
    {
        System.out.println("\t\t\t\t\t\t\tInstructions for Payroll Report Program\n\nThis program calculates a paycheck for each employee.\nA text file containing the following information will be created:\nname, pay rate, hours worked, and tax percentage to be deducted.\n\nThe program will create a report in columnar format showing the empoyee name, hourly rate, number of hours worked, tax rate, gross pay, and net pay.\n\nAfter all employees are processed, totals will be displayed, including total gross amount and total net pay.\n\n");
    }
    public static void reportTitle()
    {
        System.out.println("\t\t\t\t\t\t\t\tPayroll Report\n\nEmployee            \t\tHourly     \t\tHours       \t\tTax     \t\tGross       \t\tNet       ");
                                      System.out.println("Name\t\t\t\tRate\t\t\tWorked\t\t\tRate\t\t\tAmount\t\t\tAmount");
        System.out.println("--------------------\t\t--------\t\t--------\t\t--------\t\t--------\t\t--------");
    }
    public static void printEmployeeInfo(StringBuffer employeeName, DoubleClass hourlyRate, DoubleClass hoursWorked, DoubleClass taxRate, DoubleClass grossAmount, DoubleClass netAmount)
    {
        System.out.println(employeeName+"\t\t\t    "+hourlyRate+"   "+"\t\t    "+hoursWorked+"\t\t   "+taxRate+"   "+"\t\t  "+grossAmount+"\t\t  "+netAmount+"  OT");
    }
    public static boolean inputData(StringBuffer employeeName, DoubleClass hourlyRate, DoubleClass hoursWorked, DoubleClass taxRate)
    {
        return true;
    }
}

Please help me with the next step. I really don't know. Thanks in advance.

Answer 1

Use Scanner class to input from file and System.out.printf to formate your output. I have modified your code like below:

public class Payroll3
{
    final float FULL_TIME = 40;
    public static void main(String[] args) throws FileNotFoundException
    {
        String employeeName;
        Double hourlyRate, hoursWorked, taxRate, grossAmount=0.0, netAmount=0.0;
        instructions();
        reportTitle();
        Scanner sc=new Scanner(new File("payroll.txt"));
        while(sc.hasNext()){
             employeeName=sc.next()+" "+sc.next();
             hourlyRate=sc.nextDouble();
             hoursWorked=sc.nextDouble();
             taxRate=sc.nextDouble();
             printEmployeeInfo(employeeName, hourlyRate, hoursWorked, taxRate,   grossAmount, netAmount);
        }

    }
    public static void instructions()
    {
        System.out.println("\t\t\t\t\t\t\tInstructions for Payroll Report Program\n\nThis program calculates a paycheck for each employee.\nA text file containing the following information will be created:\nname, pay rate, hours worked, and tax percentage to be deducted.\n\nThe program will create a report in columnar format showing the empoyee name, hourly rate, number of hours worked, tax rate, gross pay, and net pay.\n\nAfter all employees are processed, totals will be displayed, including total gross amount and total net pay.\n\n");
    }
    public static void reportTitle()
    {
        System.out.println("\t\t\t\t\t\t\t\tPayroll Report\n\nEmployee            \t\tHourly     \t\tHours       \t\tTax     \t\tGross       \t\tNet       ");
                                      System.out.println("Name\t\t\t\tRate\t\t\tWorked\t\t\tRate\t\t\tAmount\t\t\tAmount");
        System.out.println("--------------------\t\t--------\t\t--------\t\t--------\t\t--------\t\t--------");
    }
    public static void printEmployeeInfo(String employeeName, Double hourlyRate, Double hoursWorked, Double taxRate, Double grossAmount, Double netAmount)
    {
        System.out.printf("%25s%20.2f%20.2f%20.2f%20.2f  OT\n",employeeName,hourlyRate,hoursWorked,taxRate,grossAmount,netAmount);
    }
//    public static boolean inputData(StringBuffer employeeName, Double hourlyRate, Double hoursWorked, Double taxRate)
//    {
//        return true;
//    }
}