在博客园撰写博客（随笔），总结7周实验内容，作业格式要求如下：
- 博文名称：学号-姓名《面向对象程序设计（java）》第七周学习总结（1分）
- 博文正文开头格式：（2分）
|
项目 |
内容 |
|
这个作业属于哪个课程 |
https://www.cnblogs.com/nwnu-daizh/ |
|
这个作业的要求在哪里 |
https://www.cnblogs.com/nwnu-daizh/p/11435127.html |
|
作业学习目标 |
|
随笔博文正文内容包括：
实验内容和步骤
实验1：（20分）
实验内容：在“System.out.println(...);”语句处按注释要求设计代码替换...，观察代码录入中IDE提示，以验证四种权限修饰符的用法
代码如下：
package ppp;
class Parent {
private String p1 = "这是Parent的私有属性";
public String p2 = "这是Parent的公有属性";
protected String p3 = "这是Parent受保护的属性";
String p4 = "这是Parent的默认属性";
private void pMethod1() {
System.out.println("我是Parent用private修饰符修饰的方法");
}
public void pMethod2() {
System.out.println("我是Parent用public修饰符修饰的方法");
}
protected void pMethod3() {
System.out.println("我是Parent用protected修饰符修饰的方法");
}
void pMethod4() {
System.out.println("我是Parent无修饰符修饰的方法");
}
}class Son extends Parent{
private String s1 = "这是Son的私有属性";
public String s2 = "这是Son的公有属性";
protected String s3 = "这是Son受保护的属性";
String s4 = "这是Son的默认属性";
public void sMethod1() {
System.out.println(p2);//分别尝试显示Parent类的p1、p2、p3、p4值
System.out.println("我是Son用public修饰符修饰的方法");
}
private void sMethod2() {
System.out.println("我是Son用private修饰符修饰的方法");
}
protected void sMethod() {
System.out.println("我是Son用protected修饰符修饰的方法");
}
void sMethod4() {
System.out.println("我是Son无修饰符修饰的方法");
}
}public class Demo {
public static void main(String[] args) {
Parent parent=new Parent();
Son son=new Son();
parent.pMethod2(); //分别尝试用parent调用Paren类的方法、用son调用Son类的方法
}
}package com.nwnu.demo1;
public class Parent {
private String p1 = "这是Parent的私有属性";
public String p2 = "这是Parent的公有属性";
protected String p3 = "这是Parent受保护的属性";
String p4 = "这是Parent的默认属性";
private void pMethod1() {
System.out.println("我是Parent用private修饰符修饰的方法");
}
public void pMethod2() {
System.out.println("我是Parent用public修饰符修饰的方法");
}
protected void pMethod3() {
System.out.println("我是Parent用protected修饰符修饰的方法");
}
void pMethod4() {
System.out.println("我是Parent无修饰符修饰的方法");
}
}package com.nwnu.demo2;
import com.nwnu.demo1.Parent;
public class Son extends Parent{
private String s1 = "这是Son的私有属性";
public String s2 = "这是Son的公有属性";
protected String s3 = "这是Son受保护的属性";
String s4 = "这是Son的默认属性";
public void sMethod1() {
System.out.println(p2);//分别尝试显示Parent类的p1、p2、p3、p4值
System.out.println("我是Son用public修饰符修饰的方法");
}
private void sMethod2() {
System.out.println("我是Son用private修饰符修饰的方法");
}
protected void sMethod() {
System.out.println("我是Son用protected修饰符修饰的方法");
}
void sMethod4() {
System.out.println("我是Son无修饰符修饰的方法");
}
}调用方法得到的结果：
调用方法四得到的结果;
得到的结果： 权限控制表
修饰词 本类 同一个包的类 继承类 其他类
private √ × × ×
无（默认） √ √ × ×
protected √ √ √ ×
public √ √ √ √
实验2：测试程序1（15分）
l 运行教材程序5-8、5-9、5-10，结合程序运行结果理解程序（教材174页-177页）；
实验代码如下：
1，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)
{
// a quick test to see if the objects are identical
if (this == otherObject) return true; //检查这些值是否相等
// must return false if the explicit parameter is null
if (otherObject == null) return false; //如果显示参数为空，则返回false
// if the classes don't match, they can't be equal
if (getClass() != otherObject.getClass()) return false; //如果类不相等，则它们不匹配
// now we know otherObject is a non-null Employee
Employee other = (Employee) otherObject; //otherObject 是一个非空雇员对象
// test whether the fields have identical values
return Objects.equals(name, other.name)
&& salary == other.salary && Objects.equals(hireDay, other.hireDay); //检测它们是否具有相同的值
}
public int hashCode()
{
return Objects.hash(name, salary, hireDay);
}
public String toString()
{
return getClass().getName() + "[name=" + name + ",salary=" + salary + ",hireDay="
+ hireDay + "]";
}
}2，package equals;
public class Manager extends Employee //子类Manager类继承父类Employee类
{ private double bonus;
public Manager(String name, double salary, int year, int month, int day) //Manager构造器
{
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; //检查是否属于同一个类
Manager other = (Manager) otherObject;
// super.equals checked that this and other belong to the same class
return bonus == other.bonus;
}
public int hashCode()
{
return java.util.Objects.hash(super.hashCode(), bonus);
}
public String toString()
{
return super.toString() + "[bonus=" + bonus + "]";
}
}package equals;
/** * This program demonstrates the equals method.
* @version 1.12 2012-01-26
* @author Cay Horstmann
*/
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());
}
}
删除程序中Employee类、Manager类中的equals()、hasCode()、toString()方法，背录删除方法，在代码录入中理解类中重写Object父类方法的技术要点。
Employee类重写后代码如下：
package equals;
import java.time.*;
import java.util.Objects;
public class Employee
{
private String name; //实例域定义
private double salary;
private LocalDate hireDay;
public Employee(String name, double salary, int year, int month, int day)//构造器定义
{
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;
}
@Override
public boolean equals(Object otherObject) {
// TODO Auto-generated method stub
if(this==otherObject) return true;
if(this==null) return false;
if(getClass() != otherObject.getClass()) return false;
Employee other=(Employee)otherObject;
return Objects.equals(name,other.name)&&salary == other.salary&&Objects.equals(hireDay,other.hireDay);
}
@Override
public int hashCode() {
// TODO Auto-generated method stub
return Objects.hash(name,salary,hireDay);
}
@Override
public String toString() {
// TODO Auto-generated method stub
return getClass().getName()+"[name="+name+",salary="+salary+",hireday="+hireDay+"]";
}
}
Manager类重写之后代码如下：
package equals;
/**
* This program demonstrates the equals method.
* @version 1.12 2012-01-26
* @author Cay Horstmann
*/
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());
}
}
(3)EmployeeTest类代码如下：
package equalspublic class Manager extends Employee{
}
}
运行结果如下：
实验2：测试程序2（15分）
l 在elipse IDE中调试运行程序5-11（教材182页），结合程序运行结果理解程序；
l 掌握ArrayList类的定义及用法；
l 在程序中相关代码处添加新知识的注释；
实验代码如下：
package arrayList;
import java.util.*;
/**
* This program demonstrates the ArrayList class.
* @version 1.11 2012-01-26
* @author Cay Horstmann
*/
public class ArrayListTest
{
public static void main(String[] args)
{
// fill the staff array list with three Employee objects
ArrayList<Employee> staff = new ArrayList<Employee>();
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));
// raise everyone's salary by 5%
for (Employee e : staff)
e.raiseSalary(5);
// print out information about all Employee objects
for (Employee e : staff)
System.out.println("name=" + e.getName() + ",salary=" + e.getSalary() + ",hireDay="
+ e.getHireDay());
}
}
（2）
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;
}
}
运行结果如下：
实验2：测试程序3（15分）
l 编辑、编译、调试运行程序5-12（教材189页），结合运行结果理解程序；
l 掌握枚举类的定义及用法；
l 在程序中相关代码处添加新知识的注释；
实验代码如下：
package enums;
import java.util.*;
/**
* This program demonstrates enumerated types.
* @version 1.0 2004-05-24
* @author Cay Horstmann
*/
public class EnumTest
{
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);
System.out.println("size=" + size);
System.out.println("abbreviation=" + size.getAbbreviation());
if (size == Size.EXTRA_LARGE)
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;
}
运行结果如下：
实验2：测试程序4（5分）
录入以下代码，结合程序运行结果了解方法的可变参数用法
public class TestVarArgus {
public static void dealArray(int... intArray){
for (int i : intArray)
System.out.print(i +" ");
System.out.println();
}
public static void main(String args[]){
dealArray();
dealArray(1);
dealArray(1, 2, 3);
}
}
运行结果如下：
实验3：编程练习（10分）
代码如下：
public class Demo {
public static void main(String[] args) {
Son son = new Son();
son.method();
}
}class Parent {
Parent() {
System.out.println("Parent's Constructor without parameter");
}
Parent(boolean b) {
System.out.println("Parent's Constructor with a boolean parameter");
}
public void method() {
System.out.println("Parent's method()");
}
}class Son extends Parent {
//补全本类定义 Son(){
super(false);
System.out.println("Son's Constructor without parameter");
}
public void method() {
System.out.println("Son's method()");
super.method();
}
}
运行结果：
3. 实验总结：（15分）
我觉得在学习理论知识时，可以跟着老师的思路，觉得已经掌握了知识点，但在实验过程中发现自己还是不会运用，肯平时没有多看书，对基础知识掌握不到位。对于老师设计的简单编程题，由于自己的知识还不够，因此几乎不能独立的做出完整的实验。所以在以后的学习中，我会多看翁恺老师的视频以及老师的课件来学习编程，来写出完整的程序。