ObjectStream Test with hierarchy
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Date;
import java.util.GregorianCalendar;
/**
* @version 1.10 17 Aug 1998
* @author Cay Horstmann
*/
public class ObjectStreamTest
{
public static void main(String[] args)
{
Employee harry = new Employee("Harry Hacker", 50000, 1989, 10, 1);
Manager carl = new Manager("Carl Cracker", 80000, 1987, 12, 15);
carl.setSecretary(harry);
Manager tony = new Manager("Tony Tester", 40000, 1990, 3, 15);
tony.setSecretary(harry);
Employee[] staff = new Employee[3];
staff[0] = carl;
staff[1] = harry;
staff[2] = tony;
try
{
// save all employee records to the file employee.dat
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("employee.dat"));
out.writeObject(staff);
out.close();
// retrieve all records into a new array
ObjectInputStream in = new ObjectInputStream(new FileInputStream("employee.dat"));
Employee[] newStaff = (Employee[]) in.readObject();
in.close();
// raise secretary's salary
newStaff[1].raiseSalary(10);
// print the newly read employee records
for (Employee e : newStaff)
System.out.println(e);
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
class Employee implements Serializable
{
public Employee()
{
}
public Employee(String n, double s, int year, int month, int day)
{
name = n;
salary = s;
GregorianCalendar calendar = new GregorianCalendar(year, month - 1, day);
hireDay = calendar.getTime();
}
public String getName()
{
return name;
}
public double getSalary()
{
return salary;
}
public Date getHireDay()
{
return hireDay;
}
public void raiseSalary(double byPercent)
{
double raise = salary * byPercent / 100;
salary += raise;
}
public String toString()
{
return getClass().getName() + "[name=" + name + ",salary=" + salary + ",hireDay=" + hireDay
+ "]";
}
private String name;
private double salary;
private Date hireDay;
}
class Manager extends Employee
{
/**
* Constructs a Manager without a secretary
* @param n the employee's name
* @param s the salary
* @param year the hire year
* @param month the hire month
* @param day the hire day
*/
public Manager(String n, double s, int year, int month, int day)
{
super(n, s, year, month, day);
secretary = null;
}
/**
* Assigns a secretary to the manager.
* @param s the secretary
*/
public void setSecretary(Employee s)
{
secretary = s;
}
public String toString()
{
return super.toString() + "[secretary=" + secretary + "]";
}
private Employee secretary;
}
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