对象流（序列化）

摘于《JAVA2核心技术第1卷》p618 - p620。具体见代码：

 

 

package test.serializable;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;


public class ObjectFileTest {
    
    public static void main(String[] args){
        Manager boss = new Manager("Carl Cracker",80000,1987,12,15);
        boss.setBonus(5000);
        Employee[] staff = new Employee[3];
        
        staff[0] = boss;
        staff[1] = new Employee("Harry Hacker",50000,1989,10,1);
        staff[2] = new Employee("Tony Tester",40000,1990,3,15);
        
        try{
            ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("employee.dat"));
            out.writeObject(staff);
            out.close();
            
            ObjectInputStream in = new ObjectInputStream((new FileInputStream("employee.dat")));
            Employee[] newStaff = (Employee[])in.readObject();
            in.close();
            
            for(Employee e : newStaff)
                System.out.println(e);
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    
}

 

package test.serializable;

import java.io.Serializable;
import java.util.Date;
import java.util.GregorianCalendar;


public class Employee implements Serializable{
    private String name;
    private double salary;
    private Date hireDay;
    
    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;
    }
    
    @Override
    public String toString(){
        return this.getClass().getName()
        + "[name=" + name
                + ",salary=" + salary
                + ",hireDay=" + hireDay
                + "]";
    }
    
}

 

package test.serializable;


public class Manager extends Employee{
    private double bonus;
    
    public Manager(String n,double s,int year,int month,int day) {
        super(n,s,year,month,day);
        bonus = 0;
    }
    
    @Override
    public double getSalary(){
        double baseSalary = super.getSalary();
        return baseSalary + bonus;
    }

    public void setBonus(double bonus) {
        this.bonus = bonus;
    }
    
    public String toString(){
        return super.toString()
        + "[bonus=" + bonus
                +"]";
    }
}