20202307 2021-2022-1 《数据结构与面向对象程序设计》实验三报告

课程：《程序设计与数据结构》
班级： 2023
姓名： 范宇涵
学号：20202307
实验教师：王志强
实验日期：2021年10月7日
必修/选修： 必修

1.实验内容

• 初步掌握单元测试和TDD

• 理解并掌握面向对象三要素：封装、继承、多态

• 初步掌握UML建模

• 完成蓝墨云上 （1）-（5）实验。

（1）参考http://www.cnblogs.com/rocedu/p/6371315.html#SECUNITTEST 完成单元测试的学习

（2）参考http://www.cnblogs.com/rocedu/p/4837092.html，以TDD的方式研究学习StringBuffer

（3）参考https://www.cnblogs.com/rocedu/p/4472842.html，对设计模式示例进行扩充，体会OCP原则和DIP原则的应用，初步理解设计模式

（4）以TDD的方式开发一个复数类Complex

（5）使用StarUML对实验二中的代码进行建模

实验一

public class shiyan1 {
    public static String percentage2fivegrade(int grade){
        //如果成绩小于0，转成“错误”
        if ((grade < 0))
            return "错误";
            //如果成绩小于60，转成“不及格”
        else if (grade < 60)
            return "不及格";
            //如果成绩在60与70之间，转成“及格”
        else if (grade < 70)
            return "及格";
            //如果成绩在70与80之间，转成“中等”
        else if (grade < 80)
            return "中等";
            //如果成绩在80与90之间，转成“良好”
        else if (grade < 90)
            return "良好";
            //如果成绩在90与100之间，转成“优秀”
        else if (grade <= 100)
            return "优秀";
            //如果成绩大于100，转成“错误”
        else
            return "错误";
    }
    }

实验二

public class shiyan2 {

   public static void main(String [] args){
                  StringBuffer buffer = new StringBuffer();
                  buffer.append('S');
                  buffer.append("tringBuffer");
                  System.out.println(buffer.charAt(1));
                  System.out.println(buffer.capacity());
                  System.out.println(buffer.indexOf("tring"));
                  System.out.println("buffer = " + buffer.toString());
               }
}

public class test1 {
    public class MyUtilTest {
        public static void main(String[] args) {
            //测试出错情况
            if(shiyan1.percentage2fivegrade(-10) != "错误")
                System.out.println("test failed 1!");
            else if(shiyan1.percentage2fivegrade(115) != "错误")
                System.out.println("test failed 2!");
            else
                System.out.println("test passed!");
        }
    }
}

public class test3 {
    public static void main(String [] args){
        StringBuffer buffer = new StringBuffer(20);
        buffer.append('S');
        buffer.append("tringBuffer");
        //    System.out.println(buffer.charAt(1));
        System.out.println(buffer.capacity());
        //    System.out.println(buffer.indexOf("tring12345"));
        System.out.println("buffer = " + buffer.toString());
        System.out.println(buffer.length());
    }
}

public class test4 {
   public static void main(String [] args){
                  StringBuffer buffer = new StringBuffer();
                  buffer.append('S');
                  buffer.append("tringBuffer");
            //    System.out.println(buffer.charAt(1));
                  System.out.println(buffer.capacity());
            //    System.out.println(buffer.indexOf("tring"));
                  System.out.println("buffer = " + buffer.toString());
                  System.out.println(buffer.length());
               }
}

 实验三

public abstract class shiyan4 {
        abstract public void DisplayValue();
    }
    class Integer extends  shiyan4 {
        int value;
        Integer() {
            value=100;
        }
        public void DisplayValue(){
            System.out.println (value);
        }
    }
    class Short extends shiyan4 {
        short value;
        Short() {
            value = (short) 20202318;
        }
        public void DisplayValue(){
            System.out.println (value);
        }
    }
    // Pattern Classes
    abstract class Factory {
        abstract public shiyan4 CreateDataObject();
    }
    class IntFactory extends Factory {
        public shiyan4 CreateDataObject(){
            return new Integer();
        }
    }
    class ShortFactory extends Factory {
        public shiyan4 CreateDataObject(){
            return new Short();
        }
    }
    //Client classes
    class Document {
        shiyan4 pd;
        Document(Factory pf){
            pd = pf.CreateDataObject();
        }
        public void DisplayData(){
            pd.DisplayValue();
        }
    }
    //Test class
    class MyDoc {
        static Document d;
        public static void main(String[] args) {
            d = new Document(new ShortFactory());
            d.DisplayData();
        }
    }

 实验四

 public class test5 { // 用于测试复数类
        public static void main(String[] args) {
            System.out.println("请用户输入第一个复数的实部和虚部:");
            shiyan3 data1 = new shiyan3();
            System.out.println("请用户输入第二个复数的实部和虚部:");
            shiyan3 data2 = new shiyan3();
// 以下分别为加减乘除
            shiyan3 result_add = data1.add(data2);
            shiyan3 result_sub = data1.sub(data2);
            shiyan3 result_mul = data1.mul(data2);
            shiyan3 result_div = data1.div(data2);
            result_add.print();
            result_sub.print();
            result_mul.print();
            result_div.print();
        }
    }

import java.util.Scanner;
public class shiyan3 { // 复数类
    double real; // 实部
    double image; // 虚部
    shiyan3(){ // 不带参数的构造方法
        Scanner input = new Scanner(System.in);
        double real = input.nextDouble();
        double image = input.nextDouble();
        Complex(real,image);
    }
    private void Complex(double real, double image) { // 供不带参数的构造方法调用
// TODO Auto-generated method stub
        this.real = real;
        this.image = image;
    }
    shiyan3(double real,double image){ // 带参数的构造方法
        this.real = real;
        this.image = image;
    }
    public double getReal() {
        return real;
    }
    public void setReal(double real) {
        this.real = real;
    }
    public double getImage() {
        return image;
    }
    public void setImage(double image) {
        this.image = image;
    }
    shiyan3 add(shiyan3 a){ // 复数相加
        double real2 = a.getReal();
        double image2 = a.getImage();
        double newReal = real + real2;
        double newImage = image + image2;
        shiyan3 result = new shiyan3(newReal,newImage);
        return result;
    }
    shiyan3 sub(shiyan3 a){ // 复数相减
        double real2 = a.getReal();
        double image2 = a.getImage();
        double newReal = real - real2;
        double newImage = image - image2;
        shiyan3 result = new shiyan3(newReal,newImage);
        return result;
    }
    shiyan3 mul(shiyan3 a){ // 复数相乘
        double real2 = a.getReal();
        double image2 = a.getImage();
        double newReal = real*real2 - image*image2;
        double newImage = image*real2 + real*image2;
        shiyan3 result = new shiyan3(newReal,newImage);
        return result;
    }
    shiyan3 div(shiyan3 a){ // 复数相除
        double real2 = a.getReal();
        double image2 = a.getImage();
        double newReal = (real*real2 + image*image2)/(real2*real2 + image2*image2);
        double newImage = (image*real2 - real*image2)/(real2*real2 + image2*image2);
        shiyan3 result = new shiyan3(newReal,newImage);
        return result;
    }
    public void print(){ // 输出
        if(image > 0){
            System.out.println(real + " + " + image + "i");
        }else if(image < 0){
            System.out.println(real + "" + image + "i");
        }else{
            System.out.println(real);
        }
    }
}

实验五

其他（感悟、思考等）

感觉本次任务难度较大，感觉自己无法跟着老师给的网址一步步走下去，越到后边越感到力不从心，以至于有一些消极对待的情绪。不过，更让我感到恐惧的是自己无法只靠自己跟上大家的步伐，于是我虚心请教老师、舍友、学长等可以给我帮助的人。到现在，我基本能照葫芦画瓢地写完一些基础的java代码。更重要的是端正学习的态度，严于律己，把每个任务完成好。