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public abstract class Employee{
 private String firstName;
 private String lastName;
 private String socialSecurityNumber;
 public Employee(String first,String last,String ssn){
  firstName=first;
  lastName=last;
  socialSecurityNumber=ssn;
 }
 public void setFirstName(String first){firstName=first;}
 public String getFirstName(){return firstName;}
 public void setLastName(String last){lastName=last;}
 public String getLastName(){return lastName;}
 public void setSocialSecurityNumber(String number){socialSecurityNumber=number;}
 public String getSocialSecurityNumber(){return socialSecurityNumber;}
 public String toString(){
  return getFirstName()+" "+getLastName()+"\n社会保险号:"+getSocialSecurityNumber();
 }
 public abstract double earnings();
}

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public class BasePlusCommissionEmployee extends CommissionEmployee{
 private double baseSalary;
 public BasePlusCommissionEmployee(String first,String last,String socialSecurityNumber,double grossSalesAmount,double rate,double baseSalaryAmount){
  super(first,last,socialSecurityNumber,grossSalesAmount,rate);
  setBaseSalary(baseSalaryAmount);
 }
 public void setBaseSalary(double salary){
  baseSalary=salary<0.0?0.0:salary;
 }
 public double getBaseSalary(){
  return baseSalary;
 }
 public double earnings(){
  return getBaseSalary()+super.earnings();
 }
 public String toString(){
  return "\n拿薪金的代理人："+super.getFirstName()+" "+super.getLastName()+"\n社会保险号："+super.getSocialSecurityNumber();
 }
}
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public class CommissionEmployee extends Employee{
 private double grossSales;
 private double commissionRate;
 public CommissionEmployee(String first,String last,String socialSecurityNumber,double grossWeeklySales,double percent){
  super(first,last,socialSecurityNumber);
  setGrossSales(grossWeeklySales);
  setCommissionRate(percent);
 }
 public void setCommissionRate(double rate){
  commissionRate=(rate>0.0&&rate<1.0)?rate:0.0;
 }
 public double getCommissionRate(){
  return commissionRate;
 }
 public void setGrossSales(double sales){
  grossSales=sales<0.0?0.0:sales;
 }
 public double getGrossSales(){
  return grossSales;
 }
 public double earnings(){
  return getCommissionRate()*getGrossSales();
 }
 public String toString(){
  return "\n代理人:"+super.toString();
 }
}

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public class HourlyEmployee extends Employee{
 private double wage;
 private double hours;
 public HourlyEmployee(String first,String last,String socialSecurityNumber,double hourlyWage,double hourlyWorked){
  super(first,last,socialSecurityNumber);
  setWage(hourlyWage);
  setHours(hourlyWorked);
 }
 public void setWage(double wageAmount){wage=wageAmount<0.0?0.0:wageAmount;}
 public double getWage(){return wage;}
 public void setHours(double hoursWorked){hours=(hoursWorked>=0.0&&hoursWorked<=168.0)?hoursWorked:0.0;
 }
 public double getHours(){return hours;}
 public double earnings(){
  if(hours<=40)
   return wage*hours;
  else
   return 40*wage+(hours-40)*wage*1.5;
 }
 public String toString