final_payroll.java

java 計薪金的program, 有save功能.

import java.util.*;
import java.io.*;
/**
 *  This is a Employee class which is used to record the full-time and part-time employee data,
 *  calculation of the employee amount, tax and holiday, and display the detail data of specific employee 
 */
abstract class Employee implements Serializable
{
	/** id is to store the employee's id number, 2 letters followed by 4 digits*/
	String id;
	/** A non-empty employee's storing*/
	String name;
	/**To store the payrate of the emlopyee (and must be >0). It is the monthly pay for FulltimeEmployee, hourly rate for ParttimeEmployee*/
	double payRate;
	/**an array of Payment objects (max 50 payments)*/
	Payment[] payments =new Payment[50];
	
	/** A constructor which accepts data for, and initializes id, name and payRate.*/
	public Employee (String id, String name, double payRate)
	{
		this.id=id;
		this.name=name;
		this.payRate=payRate;	
	}
	/** The function for returning id in string*/
	public String getId()
	{
		return (id);
	}
	/** The function for returning name in string*/
	public String getName()
	{
		return (name);
	}
	/** The function for returning payrate in double*/
	public double getPayRate()
	{
		return (payRate);
	}
	/** The function for setting id in string*/
	public void setId(String id)
	{
		this.id = id;
	}
	/** The function for setting name in string*/
	public void setName(String name)
	{
		this.name = name;
	}
	/** The function for setting payRate in double*/
	public void setPayRate(double payRate)
	{
		this.payRate = payRate;
	}

/**A method toString which returns a String which presents an employee object in the following format.
 *Payments:
 *       Date    Hours      Amount
 *  22/8/2006       20    $4000.00
 *  29/8/2006       30    $6000.00
 *   3/9/2006       20    $4000.00
 *Year pay up to today:
 *  Amount:    $14000.00
 *  Tax:           $0.00
 */
	public String toString()//overridden is needed 
	{
		int total_payment=0;
		String return_string="";
		boolean pass=true;
		while ((total_payment<50) && (pass==true))
		{
			if (payments[total_payment]==null)
				pass=false;
			if (pass!=false)
				total_payment++;
		}
		for (int i=0; i<total_payment; i++)
		{
			return_string=return_string+payments[i].toString();
		}
		String amount_string="$"+String.format("%.2f", calcYearPayment());
		String tax_string="$"+String.format("%.2f", calcYearTax(calcYearPayment()));
		return ("Payments:\n"+Payment.headerString()+return_string
				+"Year pay up to today:\n"
				+String.format("  Amount:%13s", amount_string)
				+"\n"
				+String.format("  Tax:%16s", tax_string)
				+"\n");
	}
	/**abstract method pay that adds a payment to the employee*/
	public abstract void pay();//abstract class
	/**An method calcYearPayment that calculates the yearly payment (up to today) of the employee from the array payments.*/
	public double calcYearPayment()
	{
		double total_payment=0;
		int i=0;
		boolean pass=true;
		while ((i<50) && (pass==true))
		{
			if (payments[i]==null)
				pass=false;
			if (pass!=false)
			{
				total_payment+=payments[i].getAmount();
				i++;
			}
		}
		return (total_payment);
	}
	/**
	 * A method calcYearTax that calculates the yearly tax (up to today) of the employee
	 * from on the yearly payment (up to today). The calculation of the tax is:
	 * If yearly payment <= 100000, then tax = 0;
	 * If yearly payment > 100000, then tax = (yearly payment