zoukankan      html  css  js  c++  java
  • 20175209 实验二《Java面向对象程序设计》实验报告

    20175209 实验二《Java面向对象程序设计》实验报告

    一、实验前期准备

    了解三种代码

    • 伪代码
    • 产品代码
    • 测试代码

    我们先写伪代码伪代码
    从意图层面来解决问题;
    有了伪代码
    我们用特定编程语言翻译一下,就是可用的产品代码;写完产品代码,接下来写测试代码
    证明自己的代码没有问题。Java编程时,程序员对类实现的测试叫单元测试

    二、Junit的安装和配置

    • 在IDEA中点击Setting->Plugins->Marketplace 搜索Junit下载JUnitGenerator V2.0,下载后重启IDEA即可找到下载好的Junit

    • Junit包的导入:File->Project Settings->Modules->Dependencies->'+'在你的安装IDEA的路径中找到lib文件夹导入图中的两个包后,点击OK即可正常使用

    三、实验内容

    任务1:对MyUtil类进行测试,测试用例至少要包含正常情况,错误情况,边界情况的测试。

    • 伪代码
    百分制转五分制: 如果成绩小于60,转成“不及格” 如果成绩在60与70之间,转成“及格” 如果成绩在70与80之间,转成“中等” 如果成绩在80与90之间,转成“良好” 如果成绩在90与100之间,转成“优秀” 其他,转成“错误”
    
    • 产品代码
    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
    import org.junit.Test;
    import junit.framework.TestCase;
    public class MyUtilTest extends TestCase {    
        @Test    
        public void testNormal() {        
            assertEquals("不及格", MyUtil.percentage2fivegrade(55));     
            assertEquals("及格", MyUtil.percentage2fivegrade(65));      
            assertEquals("中等", MyUtil.percentage2fivegrade(75));      
            assertEquals("良好", MyUtil.percentage2fivegrade(85));        
            assertEquals("优秀", MyUtil.percentage2fivegrade(95));    
        }    
        @Test   
        public void testExceptions() {        
            assertEquals("错误", MyUtil.percentage2fivegrade(105));        
            assertEquals("错误", MyUtil.percentage2fivegrade(-55));    
        }    
        @Test    
        public void testBoundary() {        
            assertEquals("不及格", MyUtil.percentage2fivegrade(0));       
            assertEquals("及格", MyUtil.percentage2fivegrade(60));        
            assertEquals("中等", MyUtil.percentage2fivegrade(70));        
            assertEquals("良好", MyUtil.percentage2fivegrade(80));        
            assertEquals("优秀", MyUtil.percentage2fivegrade(90));        
            assertEquals("优秀", MyUtil.percentage2fivegrade(100));    
        }
    }
    
    • 过程及结果截图

    任务2:以TDD的方式研究学习StringBuffer,提交单元测试用例和测试通过的截图。

    • 产品代码
    public class StringBufferDemo {  
        StringBuffer buffer = new StringBuffer();    
        public void 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 s) {        
            return buffer.indexOf(s);    
        }
    }
    
    • 测试代码
    import org.junit.Test;
    public class StringBufferDemoTest extends TestCase {    
        StringBuffer a = new 
        StringBuffer("StringBuffer");    
        StringBuffer b = new 
        StringBuffer("StringBufferStringBuffer");    
        StringBuffer c = new StringBuffer("StringBuffer12345StringBuffer12345");    
        @Test    
        public void testcharAt() throws Exception {       
            assertEquals('S',a.charAt(0));        
            assertEquals('u',b.charAt(7));        
            assertEquals('g',c.charAt(22));    
        }    
        @Test    
        public void testcapacity() throws  Exception {       
            assertEquals(28,a.capacity());       
            assertEquals(40,b.capacity());        
            assertEquals(50,c.capacity());    
        }    
        @Test    
        public void testlength() throws  Exception {       
            assertEquals(12,a.length());        
            assertEquals(24,b.length());        
            assertEquals(34,c.length());    
        }    
        @Test   
        public void testindexOf() throws Exception {       
            assertEquals(6,a.indexOf("Buf"));        
            assertEquals(11,b.indexOf("rSt"));       
            assertEquals(15,c.indexOf("45St"));    
        }
    }
    
    • 对capacity()方法的理解:
      capacity()用于返回当前字符串的最大容量,初始值为16,即无论字符串中是否有内容,都会被分配容量,当有字符被写入是,容量自动增加,例如当输入StringBuffer 时会增加12个大小的空间,调用capacity()会返回当前字符串最大容量28

    • 结果截图

    任务3:

    • 对设计模式示例进行扩充,体会OCP原则和DIP原则的应用。

    • 让系统支持Short类,并在MyDoc类中添加测试代码表明添加正确,提交测试代码和运行结的截图,加上学号水印。

      • S.O.L.I.D原则

        • SRP(Single Responsibility Principle,单一职责原则)
        • OCP(Open-Closed Principle,开放-封闭原则) 对扩充开放,对修改封闭:抽象和继承;面向接口编程
        • LSP(Liskov Substitusion Principle,Liskov替换原则)
        • ISP(Interface Segregation Principle,接口分离原则)
        • DIP(Dependency Inversion Principle,依赖倒置原则)

    我的学号为9,按照要求题目应为3,即让系统支持Long类,代码如下:

    public class MyDoc {    
    static Document D;    
    static Document E;    
    public static void main(String[] args) {        
        D = new Document(new IntFactory());        
        D.DisplayData();        
        E = new Document(new LongFactory());        
        E.DisplayData();    
        }
    }
    abstract class Data {    
        abstract public void DisplayValue();
    }
    class Integer extends Data {   
        int value;    
        Integer() {        
            value=100;    
        }    
        public void DisplayValue(){        
            System.out.println (value);    
        }
    }
    class Long extends Data {    
        long value;    
        Long() {        
            value = 1000000000;    
        }    
        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 LongFactory extends Factory {    
        public Data CreateDataObject(){        
            return new Long();   
        }
    }
    class Document {    
        Data pd;    
        Document(Factory pf){        
            pd = pf.CreateDataObject();    
        }    
        public void DisplayData(){        
            pd.DisplayValue();    
        }
    }
    
    • 结果截图

    任务四:以TDD的方式开发一个复数类Complex

    • 伪代码
    
    // 定义属性并生成getter,setter 
    double RealPart; 
    double ImagePart;
    
    // 定义构造函数 
    public Complex() 
    public Complex(double R,double I) 
    
    //Override Object 
    public boolean equals(Object obj) 
    public String toString() 
    
    // 定义公有方法:加减乘除 
    Complex ComplexAdd(Complex a) 
    Complex ComplexSub(Complex a) 
    Complex ComplexMulti(Complex a) 
    Complex ComplexDiv(Complex a)
    
    • 产品代码
    public class Complex {    
        double RealPart;    
        double ImagePart;    
        public Complex() {}    
        public Complex(double R,double I) {        
            RealPart = R;        
            ImagePart = I;    
        }    
        public double getRealPart() {        
            return RealPart;   
        }    
        public double getImagePart() {        
            return ImagePart;    
        }    
        public boolean equals(Object obj) {        
            if(this == obj)            
                return true;        
            if(obj == null)           
                return false;        
            if(getClass() != obj.getClass())            
                return false;       
            if(!(obj instanceof Complex))           
                return false;        
            else {            
                Complex complex = (Complex) obj;            
                if (complex.ImagePart == ((Complex) obj).ImagePart)                
                    return true;            
                if (complex.RealPart == ((Complex) obj).RealPart)               
                    return true;       
            }        
            return false;    
        }    
        public  String toString() {       
            String str = "";        
            if (RealPart == 0&&ImagePart == 0)            
                str = "0.0";        
            else if (RealPart == 0&&ImagePart != 0)           
                str = ImagePart + "" + "i";        
            else if (RealPart != 0&&ImagePart == 0)           
                str = RealPart + "";        
            else if (RealPart !=0&&ImagePart > 0)           
                str = RealPart + "" + "+" + ImagePart + "i";       
            else if (RealPart !=0&&ImagePart < 0)           
                str = RealPart + "" + ImagePart + "i";        
            return str;    
        }    
        public Complex ComplexAdd(Complex a) {        
            return new Complex(RealPart + a.getRealPart(),ImagePart + a.getImagePart());    
        }    
        public  Complex ComplexSub(Complex a) {       
            return new Complex(RealPart - a.getRealPart(),ImagePart - a.getImagePart());    
        }    
        public Complex ComplexMulti(Complex a) {       
            return new Complex(RealPart*a.getRealPart() - ImagePart*a.getImagePart(),RealPart*a.getImagePart() + 
    ImagePart*a.getRealPart());    
        }   
        public Complex ComplexDiv(Complex a) {       
            if(a.getRealPart() == 0&&a.getImagePart() == 0) {            
                System.out.println("除数不能为0");            
                return new Complex();        
            }        
            else           
                return new Complex((RealPart*a.getRealPart() - 
    ImagePart*a.getImagePart())/(a.getRealPart()*a.getRealPart()-a.getImagePart()*a.getImagePart()),(RealPart*a.getImagePart() + ImagePart*a.getRealPart())/(a.getRealPart()*a.getRealPart()-a.getImagePart()*a.getImagePart()));    
        }
    }
    
    • 测试代码
    import junit.framework.TestCase;
    import org.junit.Test;
    public class ComplexTest extends TestCase {    
        Complex a = new Complex(2.0,5.0);    
        Complex b = new Complex(1.0,-4.0);    
        Complex c = new Complex(-3.0,2.0);    
        Complex d = new Complex(-4.0,-3.0);    
        Complex e = new Complex(0.0,0.0);    
        @Test   
        public void testgetRealPart() throws Exception {        
            assertEquals(2.0,a.getRealPart());        
            assertEquals(1.0,b.getRealPart());        
            assertEquals(-3.0,c.getRealPart());        
            ssertEquals(-4.0,d.getRealPart());        
            assertEquals(0.0,e.getRealPart());    
        }    
        @Test    
        public void testgetImagePart() throws Exception {        
            assertEquals(5.0,a.getImagePart());       
            assertEquals(-4.0,b.getImagePart());       
            assertEquals(2.0,c.getImagePart());        
            assertEquals(-3.0,d.getImagePart());       
            assertEquals(0.0,e.getImagePart());    
        }   
        @Test    
        public void testequals() throws Exception {        
            assertEquals(true,a.toString().equals(a.toString()));           
            assertEquals(false,b.toString().equals(c.toString()));        
            assertEquals(false,d.toString().equals(e.toString()));    
        }   
        @Test   
        public void testtoString() throws Exception {        
            assertEquals("2.0+5.0i",a.toString());        
            assertEquals("1.0-4.0i",b.toString());        
            assertEquals("-3.0+2.0i",c.toString());        
            assertEquals("-4.0-3.0i",d.toString());        
            assertEquals("0.0",e.toString());    
        }    
        @Test    
        public void testComplexAdd() throws Exception {         
            assertEquals("3.0+1.0i",a.ComplexAdd(b).toString());        
            assertEquals("-7.0-1.0i",c.ComplexAdd(d).toString());        
            assertEquals("-4.0-3.0i",d.ComplexAdd(e).toString());    
        }    
        @Test    
        public void testComplexSub() throws Exception {        
            assertEquals("1.0+9.0i",a.ComplexSub(b).toString());        
            assertEquals("1.0+5.0i",c.ComplexSub(d).toString());        
            assertEquals("-3.0+2.0i",c.ComplexSub(e).toString());    
        }    
        public void testComplexMulti() throws Exception {        
            assertEquals("22.0-3.0i",a.ComplexMulti(b).toString());        
            assertEquals("18.0+1.0i",c.ComplexMulti(d).toString());        
            assertEquals("0.0",b.ComplexMulti(e).toString());   
        }   
        public void testComplexDiv() throws Exception {       
            assertEquals("-1.4666666666666666+0.2i",a.ComplexDiv(b).toString());                
            assertEquals("2.5714285714285716+0.14285714285714285i",c.ComplexDiv(d).toString());        
            assertEquals("0.0",a.ComplexDiv(e).toString());    
        }
    }
    
    • 结果截图

    任务5:

    • 使用StarUML对实验二中的代码进行建模,发类图的截图,加上学号水印
    • 类图中只少两个类
    • 类,继承,接口实现,组合在UML中表达

    选择画类图的题目为任务3

    四、实验中遇到的问题

    • 在按照博客中给的步骤进行任务2时按照给的代码输入后发现结果与所给的不同,反复测试后发现博客中代码存在问题,因为将代码12345添加至了第八行中,而这一行代码在执行时被注释掉不会被执行,但第五行的字符串和之前相比并没有发生改变,因此在运行时不会出现给出的结果,应该将代码12345添加至第五行的字符串末尾才能出现事例中的运行结果

    五、脚本运行截图

    六、代码托管

    https://gitee.com/wangzihong/20175209/tree/master

  • 相关阅读:
    Android的selector,背景选择器
    JAVA静态和非静态内部类
    Android应用资源--之属性(Attribute)资源
    contentprovider的学习实例总结
    转:Android 2.3 代码混淆proguard技术介绍
    忘掉旋转,利用2-3-4树,学习红黑树
    ios 定位获取当前位置信息
    地图相关
    mac下,svn配置
    NimBus一个好的开发框架
  • 原文地址:https://www.cnblogs.com/wangzihong0213/p/10733361.html
Copyright © 2011-2022 走看看