常惠琢201771010102《面向对象程序设计（java）》第七周学习总结

package equals;

/**
 * 这个程序演示了等值方法  
 * @version 1.12 2012-01-26
 * @author Cay Horstmann
 */
  //实现了Employee类和Manager类的equals、hashCode和toString方法
public class EqualsTest

   public static void main(String[] args)
   
      Employee alice1 = new Employee("Alice Adams", 75000, 1987, 12, 15);
      Employee alice2 = alice1;
      Employee alice3 = new Employee("Alice Adams", 75000, 1987, 12, 15);
      Employee bob = new Employee("Bob Brandson", 50000, 1989, 10, 1);

      System.out.println("alice1 == alice2: " + (alice1 == alice2));

      System.out.println("alice1 == alice3: " + (alice1 == alice3));

      System.out.println("alice1.equals(alice3): " + alice1.equals(alice3));

      System.out.println("alice1.equals(bob): " + alice1.equals(bob));

      System.out.println("bob.toString(): " + bob);

      Manager carl = new Manager("Carl Cracker", 80000, 1987, 12, 15);
      Manager boss = new Manager("Carl Cracker", 80000, 1987, 12, 15);
      boss.setBonus(5000);
      System.out.println("boss.toString(): " + boss);
      System.out.println("carl.equals(boss): " + carl.equals(boss));
      System.out.println("alice1.hashCode(): " + alice1.hashCode());
      System.out.println("alice3.hashCode(): " + alice3.hashCode());
      System.out.println("bob.hashCode(): " + bob.hashCode());
      System.out.println("carl.hashCode(): " + carl.hashCode());
   

package equals;

import java.time.*;
import java.util.Objects;

public class Employee

   private String name;
   private double salary;
   private LocalDate hireDay;

   public Employee(String name, double salary, int year, int month, int day)
   
      this.name = name;
      this.salary = salary;
      hireDay = LocalDate.of(year, month, day);
   

   public String getName()
   
      return name;
   

   public double getSalary()
   
      return salary;
   

   public LocalDate getHireDay()
   
      return hireDay;
   

   public void raiseSalary(double byPercent)
   
      double raise = salary * byPercent / 100;
      salary += raise;
   

   public boolean equals(Object otherObject)
   
	  // 快速测试，以查看对象是否相同
      if (this == otherObject) return true;

      // 如果explicit的参数为null，则必须返回false
      if (otherObject == null) return false;

      //如果类不匹配，它们就不能相等。 
      if (getClass() != otherObject.getClass()) return false;

      // 现在我们知道另一个对象是非null的Employee类
      Employee other = (Employee) otherObject;

      // 测试字段是否具有相同的值
      return Objects.equals(name, other.name) && salary == other.salary && Objects.equals(hireDay, other.hireDay);
   

   public int hashCode()
   
      return Objects.hash(name, salary, hireDay); 
   

   public String toString()
   
      return getClass().getName() + "[name=" + name + ",salary=" + salary + ",hireDay=" + hireDay
            + "]";
   

package equals;

public class Manager extends Employee

   private double bonus;

   public Manager(String name, double salary, int year, int month, int day)
   
      super(name, salary, year, month, day);
      bonus = 0;
   

   public double getSalary()
   
      double baseSalary = super.getSalary();
      return baseSalary + bonus;
   

   public void setBonus(double bonus)
   
      this.bonus = bonus;
   

   public boolean equals(Object otherObject)
   
      if (!super.equals(otherObject)) return false;
      Manager other = (Manager) otherObject;
      // Suff.Enter检查这个和其他属于同一个类。  
      return bonus == other.bonus;
   

   public int hashCode()
   
      return java.util.Objects.hash(super.hashCode(), bonus);
   

   public String toString()
   
      return super.toString() + "[bonus=" + bonus + "]";
   

package arrayList;

import java.util.*;

/**
 * 这个程序演示了ARAYLIST类.
 * @version 1.11 2012-01-26
 * @author Cay Horstmann
 */
public class ArrayListTest

   public static void main(String[] args)
   
      // 用三名员工对象填写员工数组列表 
      ArrayList<Employee> staff = new ArrayList<>();

      staff.add(new Employee("Carl Cracker", 75000, 1987, 12, 15));
      staff.add(new Employee("Harry Hacker", 50000, 1989, 10, 1));
      staff.add(new Employee("Tony Tester", 40000, 1990, 3, 15));

      // 把每个人的薪水提高5% 
      for (Employee e : staff)
         e.raiseSalary(5);

      //打印所有员工对象的信息 
      for (Employee e : staff)
         System.out.println("name=" + e.getName() + ",salary=" + e.getSalary() + ",hireDay="
               + e.getHireDay());
   

package arrayList;

import java.time.*;

public class Employee

   private String name;
   private double salary;
   private LocalDate hireDay;

   public Employee(String name, double salary, int year, int month, int day)
   
      this.name = name;
      this.salary = salary;
      hireDay = LocalDate.of(year, month, day);
   

   public String getName()
   
      return name;
   

   public double getSalary()
   
      return salary;
   

   public LocalDate getHireDay()
   
      return hireDay;
   

   public void raiseSalary(double byPercent)
   
      double raise = salary * byPercent / 100;
      salary += raise;
   

package enums;

import java.util.*;

/**
 * 这个程序演示枚举类型 .
 * @version 1.0 2004-05-24
 * @author Cay Horstmann
 */
public class EnumTest
  
	// 所有枚举类型都是Enum的子类
   public static void main(String[] args)
     
      Scanner in = new Scanner(System.in);
      System.out.print("Enter a size: (SMALL, MEDIUM, LARGE, EXTRA_LARGE) ");
      String input = in.next().toUpperCase();
      Size size = Enum.valueOf(Size.class, input);
      //将size设置成Size.input       
      System.out.println("size=" + size);
      System.out.println("abbreviation=" + size.getAbbreviation());
      if (size == Size.EXTRA_LARGE)   //判断语句    
         System.out.println("Good job--you paid attention to the _.");      
       
    

enum Size

   SMALL("S"), MEDIUM("M"), LARGE("L"), EXTRA_LARGE("XL");

   private Size(String abbreviation)  this.abbreviation = abbreviation; 
   public String getAbbreviation()  return abbreviation; 

   private String abbreviation;