我刚刚开始使用Java而且我遇到了一个特殊的问题，我似乎无法找到它的根源。我有两个程序，一个是从文本文件中获取数据，然后将其调用到一个类中进行一些计算，最后将输出放到另一个文本文档中。
除此部分外，一切正常：
public class Paycheck
{
//Constants for the private class
private final String EMPLOYEE_NAME; //Employee name
private final String SOC_SEC_NUM; //Employee Social Security Number
private final double WAGE_RATE; //Employee wage
private final double TAX_RATE; //Employee tax withheld
private final double HOURS_WORKED; //Employee's hours of work
//Variables for the private class
private double grossPay; //Employee Gross Pay
private double taxWithheld; //Employee Tax Withheld
private double netPay; //Employee Net Pay
//This is the constructor. It is called whenever an instance of the class is created
public Paycheck (String name, String ssn, double wage, double tax, double hours)
{
EMPLOYEE_NAME = name; //Instance employee name
SOC_SEC_NUM = ssn; //Instance employee SSN
WAGE_RATE = wage; //Instance employee wage rate
TAX_RATE = tax; //Instance employee tax rate
HOURS_WORKED = hours; //Instance employee hours worked
}
//This calculates the variables in the paycheck class
public void calcWages()
{
grossPay = WAGE_RATE * HOURS_WORKED; //Calculates Gross Pay
taxWithheld = grossPay * TAX_RATE; //Calculates Taxes Withheld
netPay = grossPay - taxWithheld; //Calculates net pay
}
//Returns the Paycheck objects Employee Name
public String getEmployeeName()
{
return EMPLOYEE_NAME;
}
//Returns the employee SSN of the Paycheck object
public String getSocSecNum()
{
return SOC_SEC_NUM;
}
//Reeturns a Paycheck object's employee Wage Rate
public double getWageRate()
{
return WAGE_RATE;
}
//Returns a Paycheck object's employee tax rate
public double getTaxRate()
{
return TAX_RATE;
}
//Returns an Paycheck object's employee hours worked
public double getHoursWorked()
{
return HOURS_WORKED;
}
//Returns a Paycheck object's gross pay
public double getGrossPay()
{
return grossPay;
}
//Returns a Paycheck object's Taxes Withheld
public double getTaxWithheld()
{
return taxWithheld;
}
//Returns a paycheck object't net pay
public double getNetPay()
{
return netPay;
}
calcWages（）进行必要的计算，下面是一系列调用它们的get语句。但是，我的输出不会返回calcWages（）参数的任何值。
我在这里添加了吸气剂，而我的其他程序正在抓住它们。但是，我的其他程序的最终输出结果为0。
我在哪里错了？
这是调用它们的主要方法的一部分
public static void main(String [] args) throws IOException //Throws clause
{
//Declare constants
final String INPUT_FILE = "Employee.txt"; //Input text file containing Employee information
final String OUTPUT_FILE= "PayrollHistory.txt"; //Output text file that will receive the data
//Declare Variables
String payPeriodDate; //Ending date of the pay period
String employeeName; //Employee Name in text file
String employeeSocSecNum; //Employee SSN in text file
double employeeHours; //Employee hours worked
double employeeTax; //Employee Tax rate
double employeeWage; //Employee Wage rate
double totalGrossPay; //Total employee Gross for pay period
double totalTaxWithheld; //Total Tax Withheld for pay period
double totalNetPay; //Total Net Payroll for pay period
String input; //String input for double conversion in JoptionPane
DecimalFormat money = new DecimalFormat ("#0.00"); // Decimal Format to put money in the right format(USD)
//This ensures that the input file actually exists in the program folder
//And exits the program if it does not, along with the prompt.
File file = new File(INPUT_FILE);
if (!file.exists())
{
JOptionPane.showMessageDialog(null, "The " + INPUT_FILE + " file cannot be found." +
"Program terminated.");
System.exit(0);
}
// Create Scanner object to enable reading data from input file
Scanner inputFile = new Scanner(file);
// Create FileWriter and PrintWriter objects to enable
// writing (appending not overwriting) data to text file
FileWriter fwriter = new FileWriter(OUTPUT_FILE, true);
PrintWriter outputFile = new PrintWriter(fwriter);
//Initialize accumulator values
totalGrossPay = 0.0;
totalTaxWithheld = 0.0;
totalNetPay = 0.0;
//Get the pay period for the employee
payPeriodDate = JOptionPane.showInputDialog("Enter pay period ending date (mm/dd/yyyy):");
outputFile.println("PAY PERIOD ENDING DATE: " + payPeriodDate); //Inputs pay period date into the text file
outputFile.println(); // Blank line
outputFile.println(); // Blank line
while (inputFile.hasNext()) // This will look through the input file and get the necessary variable input
{
// Read employee Name from Input File
employeeName = inputFile.nextLine();
// Read employee SSN from input file
employeeSocSecNum = inputFile.nextLine();
// Read employee Wage Rate from input file
//Parses it into a double type
input = inputFile.nextLine();
employeeWage = Double.parseDouble(input);
//Read employee tax rate from input file
//Parses it into a double type
input = inputFile.nextLine();
employeeTax = Double.parseDouble(input);
//Get number of hours worked
input = JOptionPane.showInputDialog("Employee Name: " + employeeName +
"\nEnter number of hours worked:");
employeeHours = Double.parseDouble(input);
//This call the paycheck class to create a new Paycheck Object
Paycheck employee = new Paycheck (employeeName, employeeSocSecNum, employeeWage, employeeTax, employeeHours);
// Call Paycheck class methods into the output file
outputFile.println("Employee Name: " + employeeName); //Employee Name
outputFile.println("SSN: " + employeeSocSecNum); //Employee SSN
outputFile.println("Hours Worked: " + employeeHours); //Employee Hours Worked
outputFile.println("Wage Rate: " + money.format(employeeWage)); //Employee Wage Rate
outputFile.println("Gross Pay: " + money.format(employee.getGrossPay())); //Employee Gross Pay
outputFile.println("Tax Rate: " + money.format(employeeTax)); //Employee Tax Rate
outputFile.println("Tax Withheld: " + money.format(employee.getTaxWithheld())); //Employee Tax Withheld
outputFile.println("Net Pay: " + employee.getNetPay()); //Employee Net Pay
outputFile.println(); // Blank line
答案 0 :(得分：3)
在调用getter之前，你似乎并没有实际调用 calcWages()，所以grossPay, taxWithheld, and netPay仍然是0，因为这是Java未初始化数字的默认值
在引用这些值之前，您需要先调用employee.calcWages()才能更改。
答案 1 :(得分：0)
这是因为calcWages()被声明为 void （public void calcWages()），这意味着它不应该返回任何值，而只是完成一系列步骤（计算工资单细节）这个例子）。调用它之后，继续引用它处理的实例变量。
答案 2 :(得分：0)
您已将变量声明为final，这意味着它们只能分配一次。