20202307 实验三《面向对象程序设计》实验报告

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

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

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

实验过程及结果

单元测试

产品代码
package Exp3_1;

public class MyUtil{
    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";
        }
    }
}
测试代码
package Exp3_1;

import org.junit.Assert;
import org.junit.Test;

/**
 * @author 20202307
 */
public class MyUtilTest {
    @Test
    public void testNormal() {
        Assert.assertEquals("不及格", MyUtil.percentage2fivegrade(55));
        Assert.assertEquals("及格", MyUtil.percentage2fivegrade(65));
        Assert.assertEquals("中等", MyUtil.percentage2fivegrade(75));
        Assert.assertEquals("良好", MyUtil.percentage2fivegrade(85));
        Assert.assertEquals("优秀", MyUtil.percentage2fivegrade(95));
    }

    @Test
    public void testExceptions() {
        Assert.assertEquals("错误", MyUtil.percentage2fivegrade(-55));
        Assert.assertEquals("错误", MyUtil.percentage2fivegrade(105));
    }

    @Test
    public void testBoundary() {
        Assert.assertEquals("不及格", MyUtil.percentage2fivegrade(0));
        Assert.assertEquals("及格", MyUtil.percentage2fivegrade(60));
        Assert.assertEquals("中等", MyUtil.percentage2fivegrade(70));
        Assert.assertEquals("良好", MyUtil.percentage2fivegrade(80));
        Assert.assertEquals("优秀", MyUtil.percentage2fivegrade(90));
        Assert.assertEquals("优秀", MyUtil.percentage2fivegrade(100));
    }
}

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/MyUtil.java

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/MyUtilTest.java

以TDD的方式研究学习StringBuffer

产品代码
package Exp3_2;

public class StringBufferDemo {
    StringBuffer buffer = new StringBuffer();
    public StringBufferDemo(StringBuffer buffer){
        this.buffer = buffer;
    }
    public Character charAt(int i){
        return buffer.charAt(i);
    }
    public int capacity(){
        return buffer.capacity();
    }
    public int length(){
        return buffer.length();
    }
    public int indexOf(String buf) {
        return buffer.indexOf(buf);
    }
}
测试代码
package Exp3_2;

import junit.framework.TestCase;
import org.junit.Test;

public class StringBufferDemoTest extends TestCase {
    StringBuffer a = new StringBuffer("StringBuffer");//测试12个字符（<=16）
    StringBuffer b = new StringBuffer("StringBufferStringBuffer");//测试24个字符（>16&&<=34）
    StringBuffer c = new StringBuffer("StringBufferStringBufferStringBuffer");//测试36个字符（>=34）
    @Test
    public void testcharAt() throws Exception{
        assertEquals('S',a.charAt(0));
        assertEquals('g',a.charAt(5));
        assertEquals('r',a.charAt(11));
    }
    @Test
    public void testcapacity() throws Exception{
        assertEquals(28,a.capacity());
        assertEquals(40,b.capacity());
        assertEquals(52,c.capacity());
    }
    @Test
    public void testlength() throws Exception{
        assertEquals(12,a.length());
        assertEquals(24,b.length());
        assertEquals(36,c.length());
    }
    @Test
    public void testindexOf() throws Exception{
        assertEquals(0,a.indexOf("Str"));
        assertEquals(5,a.indexOf("gBu"));
        assertEquals(10,a.indexOf("er"));
    }
}

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/StringBufferDemo.java

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/StringBufferDemoTest.java

对设计模式示例进行扩充，体会OCP原则和DIP原则的应用

package Exp3_3;

abstract class Data{
    abstract public void DisplayValue();
}

class Integer extends Data {
    int value;
    Integer(){
        value = 32767;
    }
    public void DisplayValue(){
        System.out.println(value);
    }
}

class Short extends Data {
    short value;
    Short(){
        value = (short) 32768;
    }
    public void DisplayValue(){
        System.out.println(value);
    }
}

abstract class Factory{
    abstract public Data CreateDataObject();
}

class IntFactory extends Factory {
    public Data CreateDataObject(){
        return new Integer();
    }
}

class Document{
    Data pd;
    Document(Factory pf){
        pd = pf.CreateDataObject();
    }
    public void DisplayData(){
        pd.DisplayValue();
    }
}

class DoubleFactory extends Factory {
    public Data CreateDataObject(){
        return new Short();
    }
}

public class MyDoc {
    static Document i,d;
    public static void main(String[] args) {
        int a = 20202307%6;
        System.out.println("学号运算结果为："+a);
        i = new Document(new IntFactory());
        i.DisplayData();
        d = new Document(new DoubleFactory()) ;
        d.DisplayData();
    }
}

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/MyDoc.java

以TDD的方式开发一个复数类Complex

产品代码
package Exp3_4;

public class Complex{
    private double r;
    private double i;
    public Complex(double r, double i) {
        this.r = r;
        this.i = i;
    }

    public static double getRealPart(double r) {
        return r;
    }

    public static double getImagePart(double i) {
        return i;
    }

    public Complex ComplexAdd(Complex c) {
        return new Complex(r + c.r, i + c.i);
    }
    public Complex ComplexSub(Complex c) {
        return new Complex(r - c.r, i - c.i);
    }
    public Complex ComplexMulti(Complex c) {
        return new Complex(r * c.r - i * c.i, r * c.i + i * c.r);
    }
    public Complex ComplexDiv(Complex c) {
        return new Complex((r * c.i + i * c.r)/(c.i * c.i + c.r * c.r), (i * c.i + r * c.r)/(c.i * c.i + c.r * c.r));
    }

    public String toString() {
        String s = " ";
        if (i > 0)
            s =  r + "+" + i + "i";
        if (i == 0)
            s =  r + "";
        if (i < 0)
            s = r + " " + i + "i";
        return s;
    }
}
测试代码
package Exp3_4;

import junit.framework.TestCase;
import org.junit.Test;

import static junit.framework.TestCase.assertEquals;

public class ComplexTest extends TestCase {
    Complex c1 = new Complex(0, 3);
    Complex c2 = new Complex(-1, -1);
    Complex c3 = new Complex(2,1);
    @Test
    public void testComplexAdd() throws Exception {
        assertEquals("-1.0+2.0i", c1.ComplexAdd(c2).toString());
        assertEquals("2.0+4.0i", c1.ComplexAdd(c3).toString());
        assertEquals("1.0", c2.ComplexAdd(c3).toString());
    }
    @Test
    public void testComplexSub() throws Exception {
        assertEquals("1.0+4.0i", c1.ComplexSub(c2).toString());
        assertEquals("-2.0+2.0i", c1.ComplexSub(c3).toString());
        assertEquals("-3.0 -2.0i", c2.ComplexSub(c3).toString());
    }
    @Test
    public void testComplexMulti() throws Exception {
        assertEquals("3.0 -3.0i", c1.ComplexMulti(c2).toString());
        assertEquals("-3.0+6.0i", c1.ComplexMulti(c3).toString());
        assertEquals("-1.0 -3.0i", c2.ComplexMulti(c3).toString());
    }
    @Test
    public void testComplexDiv() throws Exception {
        assertEquals("-1.5 -1.5i", c1.ComplexDiv(c2).toString());
        assertEquals("1.2+0.6i", c1.ComplexDiv(c3).toString());
        assertEquals("-0.6 -0.6i", c2.ComplexDiv(c3).toString());
    }
    @Test
    public void testgetRealPart() throws Exception {
        assertEquals(-1.0, Complex.getRealPart(-1.0));
        assertEquals(5.0, Complex.getRealPart(5.0));
        assertEquals(0.0, Complex.getRealPart(0.0));
    }
    @Test
    public void testgetImagePart() throws Exception {
        assertEquals(-1.0, Complex.getImagePart(-1.0));
        assertEquals(5.0, Complex.getImagePart(5.0));
        assertEquals(0.0, Complex.getImagePart(0.0));
    }
}

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/Complex.java

https://gitee.com/besti2023javads/fan-yuhan-20202307/blob/master/src/Exp3/ComplexTest.java

对上一实验代码进行建模

实验过程中遇到的问题和解决过程

问题1：控制台输出中文乱码

问题1解决方案：在IDEA安装目录下找到idea.exe文件，编辑文件，在文件内容的末尾添加-Dfile.encoding=UTF-8。

找到项目目录下的.idea的文件夹，打开文件encodings.xml，将其中除UTF-8外的代码删除。

运行成功！！

其他（感悟、思考等）

随着课程学习不断深入，需要掌握的知识的深度和难度都在增加。本次实验过程中可谓“一步一个坎”，代码看似完全正确，看起来与标准示例也相差无两，但运行起来总是不断地报错，一个又一个提示运行错误的弹出框让人倍受折磨。明明是完全根据教程的规范步骤操作，可IDEA给出的反应总是不按套路出牌。比如中文乱码的问题，我按照各个网站的帖子试了很多种方法，才终于解决掉这个棘手的问题。每一步的操作、每一句代码的编写都需要充分理解操作背后的原理，真正将知识研习透彻，闯过提示错误的一个个难关，才能走向最后的胜利。
　　

参考资料

posted @ 2021-10-12 21:35 20202307范宇涵阅读(148) 评论(0) 编辑收藏举报

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20202307 实验三 《面向对象程序设计》实验报告