2018-2019-2 20175228实验二《面向对象程序设计》实验报告

一、实验内容及步骤

（一）单元测试

（1）三种代码

①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”

②产品代码

public class MyUtil{
   public static String percentage2fivegrade(int grade){
       //如果成绩小于60，转成“不及格”
       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";
       //其他，转成“错误”
       else 
           return "错误";
   }
}

③测试代码

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

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 testException(){
        assertEquals("错误",MyUtil.percentage2fivegrade(-55));
        assertEquals("错误",MyUtil.percentage2fivegrade(115));
    }
    @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));
    }

}

（2）安装JUnit：File-Settings-Plugins-Marketplace

搜索JUnit，点击Install，之后重启IDEA安装成功。

（3）进行代码测试，测试正常、异常、边界结果如下：

（二）以TDD的方式研究学习StringBuffer

1、老师给出的StringBuffer的例子：

public class StringBufferDemo{        
   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());    
  }    
}    

2、改写代码使其可以进行JUnit测试

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);
    }
}

3、测试代码

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

public class StringBufferDemoTest extends TestCase {
    StringBuffer a1 = new StringBuffer("StringBuffer");
    StringBuffer a2 = new StringBuffer("StringBufferStringBuffer");
    StringBuffer a3 = new StringBuffer("StringBuffer used by 20175215");
    @Test
    public void testCharAt() throws Exception{//验证返回是否是整个字符串中的第x个字符
        assertEquals('S',a1.charAt(0));
        assertEquals('t',a2.charAt(13));
        assertEquals('b',a3.charAt(18));
    }
    @Test
    public void testcapacity() throws Exception{//验证容量
        assertEquals(28,a1.capacity());
        assertEquals(40,a2.capacity());
        assertEquals(45,a3.capacity());
    }
    @Test
    public void testlength() throws Exception{//验证字符串的长度
        assertEquals(12,a1.length());
        assertEquals(24,a2.length());
        assertEquals(29,a3.length());
    }
    @Test
    public void testindexOf(){//验证所在位置
        assertEquals(6,a1.indexOf("Buff"));
        assertEquals(1,a2.indexOf("tring"));
        assertEquals(25,a3.indexOf("5215"));
    }
}

4.测试结果：

（三）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

1、产品代码

abstract class Data {
    abstract public void DisplayValue();
}
class Integer extends  Data {
    int value;
    Integer() {
        value=100;
    }
    @Override
    public void DisplayValue(){
        System.out.println (value);
    }
}
class Float extends Data {
    float value;
    Float() {
        value = 20175228;
    }
    @Override
    public void DisplayValue(){
        System.out.println (value);
    }
}
// Pattern Classes
abstract class Factory {
    abstract public Data CreateDataObject();
}
class IntFactory extends Factory {
    public Data CreateDataObject(){
        return new Integer();
    }
}
class FloatFactory extends Factory {
    public Data CreateDataObject(){
        return new Float();
    }
}
//Client classes
class Document {
    Data pd;
    Document(Factory pf){
        pd = pf.CreateDataObject();
    }
    public void DisplayData(){
        pd.DisplayValue();
    }
}

public class MyDoc {
    static Document d;
    public static void main(String[] args) {
        d = new Document(new FloatFactory());
        d.DisplayData();
    }
}

2、运行结果截图：

（四）以TDD的方式开发一个复数类Complex

1、产品代码

public class ComplexNumber {
    double RealPart;
    double ImagePart;
    public ComplexNumber(){
        this.ImagePart=0;
        this.RealPart=0;
    }
    public ComplexNumber(double RealPart, double ImagePart) {
        this.RealPart = RealPart;
        this.ImagePart = ImagePart;
    }
    public  double getRealPart(){
        return this.RealPart;
    }
    public double getImagePart(){
        return this.ImagePart;
    }

    public double setRealPart(double R){
        this.RealPart = R;
        return R;
    }
    public double setImagePart(double I){
        this.ImagePart = I;
        return I;
    }
    ComplexNumber ComplexAdd(ComplexNumber a){
        double R = a.getRealPart();
        double I = a.getImagePart();
        double cr = R + this.RealPart;
        double ci = I + this.ImagePart;
        ComplexNumber c = new ComplexNumber(cr,ci);
        return c;
    }
    ComplexNumber ComplexSub(ComplexNumber a){
        double R = a.getRealPart();
        double I = a.getImagePart();
        double cr = R - this.RealPart;
        double ci = I - this.ImagePart;
        ComplexNumber c = new ComplexNumber(cr,ci);
        return c;
    }
    ComplexNumber ComplexMultib(ComplexNumber a){
        double R = a.getRealPart();
        double I = a.getImagePart();
        double cr = R * this.RealPart;
        double ci = I * this.ImagePart;
        ComplexNumber c = new ComplexNumber(cr,ci);
        return c;
    }
    ComplexNumber ComplexDiv(ComplexNumber a){
        double R = a.getRealPart();
        double I = a.getImagePart();
        double cr = R / this.RealPart;
        double ci = I / this.ImagePart;
        ComplexNumber c = new ComplexNumber(cr,ci);
        return c;
    }
    public String toString() {
        String complex=new String();
        if (ImagePart > 0)
            complex = "(" + RealPart + "+" + ImagePart + "i" + ")";
        if (ImagePart == 0)
            complex = "(" + RealPart + ")" ;
        if (ImagePart < 0)
            complex = "(" + RealPart + "-" + ImagePart + "i" + ")";
        return complex;
    }
}

2、测试代码

import junit.framework.TestCase;
import org.junit.Test;
public class ComplexNumberTest extends TestCase {
    ComplexNumber a=new ComplexNumber(14,4);
    ComplexNumber b=new ComplexNumber(5,-2);
    ComplexNumber c=new ComplexNumber(2,1);
    ComplexNumber d=new ComplexNumber(4,0);
    ComplexNumber m=new ComplexNumber();
    @Test
    public void testGetRealPart() throws Exception {
        assertEquals(14.0,a.getRealPart());
        assertEquals(5.0,b.getRealPart());
    }

    @Test
    public void testGetImagePart() throws Exception {
        assertEquals(4.0,a.getImagePart());
        assertEquals(-2.0,b.getImagePart());
    }

    @Test
    public void testSetRealPart() throws Exception {
        m.setRealPart(1);
        assertEquals(1.0,m.getRealPart());
    }

    @Test
    public void testSetImagePart() throws Exception {
        m.setImagePart(4);
        assertEquals(4.0,m.getImagePart());
    }

    @Test
    public void testComplexNumberAdd() throws Exception {
        m=a.ComplexAdd(b);
        assertEquals("(19.0+2.0i)",m.toString());
        m=a.ComplexAdd(c);
        assertEquals("(16.0+5.0i)",m.toString());
    }

    @Test
    public void testComplexNumberSub() throws Exception {
        m=b.ComplexSub(a);
        assertEquals("(9.0+6.0i)",m.toString());
        m=c.ComplexSub(b);
        assertEquals("(3.0--3.0i)",m.toString());
    }

    @Test
    public void testComplexNumberMultib() throws Exception {
        m=a.ComplexMultib(b);
        assertEquals("(70.0--8.0i)",m.toString());
        m=a.ComplexMultib(c);
        assertEquals("(28.0+4.0i)",m.toString());

    }
    @Test
    public void testComplexNumberDiv() throws Exception {
        m=c.ComplexDiv(a);
        assertEquals("(7.0+4.0i)",m.toString());
        m=c.ComplexDiv(b);
        assertEquals("(2.5--2.0i)",m.toString());

    }

}

3、测试截图

（五）使用StarUML对实验二中的代码进行建模

二、实验中遇到的问题

问题1：Test文件显示出错。

问题1解决方案：如下图所示，File-Project Structure-Dependices，点击“+”选择如下的jar文件即可。