public static void main(String[] args){
Employee[] empList = new Employee[2];
for(int i=0; i < empList.length; i++){
String empType = JOptionPane.showInputDialog("Enter S for a salaried employee or H for an hourly employee.");
if (empType.charAt(0) == 's' || empType.charAt(0) == 'S'){
empList[i] = new Salaried();
collectEmpInfo(empList[i]);
displayEmpInfo(empList[i]);
System.out.println("Number of Employees: " + Salaried.getNumEmployees());
}
else if (empType.charAt(0) == 'h' || empType.charAt(0) == 'H'){
empList[i] = new Hourly();
collectEmpInfo(empList[i]);
displayEmpInfo(empList[i]);
System.out.println("Number of Employees: " + Hourly.getNumEmployees());
}
else{
JOptionPane.showMessageDialog(null, "Invalid Employee Type");
//reset i for this iteration if input is invalid
i--;
}
}
}
import java.text.NumberFormat;
public abstract class Employee {
protected String firstName;
protected String lastName;
protected char gender;
protected int dependents;
protected double annualSalary;
protected static int numEmployees = 0;
public Benefit benefit;
public Employee(){
firstName = "not given";
lastName = "not given";
gender = 'U';
dependents = 0;
annualSalary = 20000;
benefit = new Benefit();
}
public Employee(String first, String last, char gen, int dep, double salary, Benefit ben){
firstName = first;
lastName = last;
gender = gen;
dependents = dep;
annualSalary = salary;
numEmployees += 1;
benefit = ben;
}
public String toString(){
NumberFormat nf = NumberFormat.getCurrencyInstance();
return "First Name:" + firstName +
"\nLast Name: " + lastName +
"\nGender: " + gender +
"\nDependents: " + dependents +
"\nAnnual Salary: " + nf.format(annualSalary) +
"\nEmployee weekly pay: " + nf.format(calculatePay()) +
benefit.toString();
}
public String getFirstName(){
return firstName;
}
public void setFirstName(String first){
firstName = first;
}
public String getLastName(){
return lastName;
}
public void setLastName(String last){
lastName = last;
}
public char getGender(){
return gender;
}
public void setGender(char gen){
gender = gen;
}
public int getDependents(){
return dependents;
}
public void setDependents(int dep){
dependents = dep;
}
public double getAnnualSalary(){
return annualSalary;
}
public void setAnnualSalary(double salary){
annualSalary = salary;
}
public static int getNumEmployees(){
return numEmployees;
}
public void setDependents(String dep){
dependents = Integer.parseInt(dep);
}
public void setAnnualSalary(String sal){
annualSalary = Double.parseDouble(sal);
}
public abstract double calculatePay();
}
public class Benefit {
private String healthInsurance;
private double lifeInsurance;
private int vacation;
public Benefit(){
healthInsurance = "Full";
lifeInsurance = 1000;
vacation = 5;
}
public Benefit(String health, double life, int vacation){
healthInsurance = health;
lifeInsurance = life;
this.vacation = vacation;
}
public String toString(){
return "\nHealth Insurance: " + healthInsurance +
"\nLife Insurance: " + lifeInsurance +
"\nVacation: " + vacation;
}
public String getHealthInsurance(){
return healthInsurance;
}
public void setHealthInsurance(String hins){
healthInsurance = hins;
}
public double getLifeInsurance(){
return lifeInsurance;
}
public void setLifeInsurance(double lifeins){
lifeInsurance = lifeins;
}
public int getVacation(){
return vacation;
}
public void setVacation(int vaca){
vacation = vaca;
}
}
import java.text.NumberFormat;
public class Salaried extends Employee{
private final static int MIN_MANAGEMENT_LEVEL = 0;
private final static int MAX_MANAGEMENT_LEVEL = 3;
private final static double BONUS_PERCENT = 0.10;
private int managementLevel;
public Salaried(){
firstName = "not given";
lastName = "not given";
gender = 'U';
dependents = 0;
annualSalary = 20000;
benefit = new Benefit();
managementLevel = 0;
}
public Salaried(int managementLevel){
firstName = "not given";
lastName = "not given";
gender = 'U';
dependents = 0;
annualSalary = 20000;
benefit = new Benefit();
numEmployees +=1;
this.managementLevel = (managementLevel >= MIN_MANAGEMENT_LEVEL && managementLevel <= MAX_MANAGEMENT_LEVEL)? managementLevel : 0;
}
public Salaried(String first, String last, char gen, int dep, double salary, Benefit bene, int managementLevel){
firstName = first;
lastName = last;
gender = gen;
dependents = dep;
annualSalary = salary;
numEmployees += 1;
benefit = bene;
this.managementLevel = (managementLevel >= MIN_MANAGEMENT_LEVEL && managementLevel <= MAX_MANAGEMENT_LEVEL)? managementLevel : 0;
}
public double calculatePay(){
double bonusPercentage = managementLevel * BONUS_PERCENT;
double weeklyBonus = bonusPercentage * annualSalary;
double weeklyPay = annualSalary/52 + weeklyBonus/52;
return weeklyPay;
}
public String toString(){
NumberFormat nf = NumberFormat.getCurrencyInstance();
return "First Name:" + firstName +
"\nLast Name: " + lastName +
"\nGender: " + gender +
"\nDependents: " + dependents +
"\nAnnual Salary: " + nf.format(annualSalary) +
"\nEmployee weekly pay: " + nf.format(calculatePay()) +
benefit.toString() +
"\nManagement Level: " + managementLevel;
}
public void setManagementLevel(int manLevel){
managementLevel = (manLevel >= MIN_MANAGEMENT_LEVEL && manLevel <= MAX_MANAGEMENT_LEVEL)? manLevel : 0;
}
public int getManagementLevel(){
return managementLevel;
}
}
import java.text.NumberFormat;
public class Hourly extends Employee{
private static final double MIN_WAGE = 10;
private static final double MAX_WAGE = 75;
private static final double MIN_HOURS = 0;
private static final double MAX_HOURS = 50;
private double wage;
private double hours;
private String category;
public Hourly(){
wage = 0;
hours = 0;
category = "";
firstName = "not given";
lastName = "not given";
gender = 'U';
dependents = 0;
annualSalary = 20000;
numEmployees +=1;
benefit = new Benefit();
}
public Hourly(double wage, double hours, String category){
this.wage = (wage >= MIN_WAGE && wage <= MAX_WAGE)? wage : 10;
this.hours = (hours >= MIN_HOURS && hours <= MAX_HOURS)? hours : 0;
this.category = (category.equalsIgnoreCase("temporary") || category.equalsIgnoreCase("full time") || category.equalsIgnoreCase("part time"))?
category: "Invalid category";
firstName = "not given";
lastName = "not given";
gender = 'U';
dependents = 0;
annualSalary = 20000;
benefit = new Benefit();
}
public Hourly(String first, String last, char gen, int dep, Benefit bene, double wage, double hours, String category){
this.wage = (wage >= MIN_WAGE && wage <= MAX_WAGE)? wage : 10;
this.hours = (hours >= MIN_HOURS && hours <= MAX_HOURS)? hours : 0;
this.category = (category.equalsIgnoreCase("temporary") || category.equalsIgnoreCase("full time") || category.equalsIgnoreCase("part time"))?
category: "Invalid category";
double salary = wage * hours * 52;
firstName = first;
lastName = last;
gender = gen;
dependents = dep;
annualSalary = salary;
numEmployees += 1;
benefit = bene;
}
public String toString(){
NumberFormat nf = NumberFormat.getCurrencyInstance();
return "First Name:" + firstName +
"\nLast Name: " + lastName +
"\nGender: " + gender +
"\nDependents: " + dependents +
"\nAnnual Salary: " + nf.format(annualSalary) +
"\nEmployee weekly pay: " + nf.format(calculatePay()) +
benefit.toString() +
"\nCategory: " + category;
}
public double getWage() {
return wage;
}
public void setWage(double wage) {
this.wage = (wage >= MIN_WAGE && wage <= MAX_WAGE)? wage : 10;
annualSalary = wage * hours *52;
}
public double getHours() {
return hours;
}
public void setHours(double hours) {
this.hours = (hours >= MIN_HOURS && hours <= MAX_HOURS)? hours : 0;
annualSalary = wage * hours * 52;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = (category.equalsIgnoreCase("temporary") || category.equalsIgnoreCase("full time") || category.equalsIgnoreCase("part time"))?
category: "Invalid category";
}
public double calculatePay(){
return wage * hours;
}
}
Employee是一个包含静态int numEmployees的抽象类。 Salaried和Hourly是员工的子类。 Salaried和Hourly中的构造函数增加numEmployees + = 1，那么为什么当我调用Salaried / Hourly.getNumEmployees（）时它返回0？
答案 0 :(得分：2)
没有参数的构造函数（在main中调用的构造函数）不会递增计数器。 编辑：好吧，至少不是Salaried中的那个...
此外，计数器可能无法按预期工作，因为所有子类只有一个静态计数器。
Java中的静态字段不是学习继承的好方法。它们的行为大多类似于全局变量。如果您想学习继承和多态，您应该专注于非静态方法。如果需要，您可以按照评论中的建议创建“公司”类。