java作业题，这个题该怎么写啊，求解，谢谢！

public interface IEmployee {
final double PRIZE=1000;
public abstract void addSalary();

}

public abstract class People {
public String name;
public int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}

}

import java.sql.Timestamp;

public class Employee extends People implements IEmployee{
public double salary;
public Timestamp hireDay;

public double getSalary() {
return salary;
}

public void setSalary(double salary) {
this.salary = salary;
}

public Timestamp getHireDay() {
return hireDay;
}

public void setHireDay(Timestamp hireDay) {
this.hireDay = hireDay;
}

public void getInfo(){

System.out.println("员工信息");

}

public void addSalary() {
double addSalaryResult=salary+PRIZE;
System.out.println(addSalaryResult);

}
}

import java.sql.Timestamp;

public class Employee extends People implements IEmployee{
public double salary;
public Timestamp hireDay;

public double getSalary() {
return salary;
}

public void setSalary(double salary) {
this.salary = salary;
}

public Timestamp getHireDay() {
return hireDay;
}

public void setHireDay(Timestamp hireDay) {
this.hireDay = hireDay;
}

public void getInfo(){

System.out.println("员工信息");

}

public void addSalary() {
double addSalaryResult=salary+PRIZE;
System.out.println(addSalaryResult);

}
}

import java.sql.Timestamp;

public class Employee extends People implements IEmployee{
public double salary;
public Timestamp hireDay;

public double getSalary() {
return salary;
}

public void setSalary(double salary) {
this.salary = salary;
}

public Timestamp getHireDay() {
return hireDay;
}

public void setHireDay(Timestamp hireDay) {
this.hireDay = hireDay;
}

public void getInfo(){

System.out.println("员工信息");

}

public void addSalary() {
double addSalaryResult=salary+PRIZE;
System.out.println(addSalaryResult);

}
}

public class Manager extends Employee{

public double bonus;
public int holidays;

public void addSalary() {

double addSalaryResult=5000+2*PRIZE;
System.out.println("重写后的"+addSalaryResult);
}

public double getSalary() {
return salary;
}

public void getInfo(){

System.out.println("重写后的员工信息");

}

}

public class ManageEmployeeSalary {
public static void main(String args[]){
Manager manager=new Manager();
manager.setName("张三");
manager.setAge(30);
System.out.println(manager.getName());
System.out.println(manager.getAge());
manager.getInfo();
manager.addSalary();
}
}

这个都算是一个大作业了 ，不难 有点多。。。。懒