corejava第7版

corejava第7版/v1/v1ch12/ObjectRefTest/ObjectRefTest.java

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+/**
+   @version 1.10 17 Aug 1998
+   @author Cay Horstmann
+*/
+
+
+import java.io.*;
+import java.util.*;
+
+class ObjectRefTest
+{  
+   public static void main(String[] args)
+   {  
+      Employee harry = new Employee("Harry Hacker", 50000, 1989, 10, 1);
+      Manager boss = new Manager("Carl Cracker", 80000, 1987, 12, 15);
+      boss.setSecretary(harry);
+
+      Employee[] staff = new Employee[3];
+
+      staff[0] = boss;
+      staff[1] = harry;
+      staff[2] = new Employee("Tony Tester", 40000, 1990, 3, 15);
+      
+      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;
+}
+