实验二《面向对象程序设计》_实验报告

一、实验前期预习准备

Junit的安装和配置

• 选择File->Setting打开设置对话框,在设置对话框中选择Plugins, 单击Install JetBrains plugin...按钮打开插件安装界面：
• 在插件安装对话框的搜索中输入junit,单击JunitGenerator V2.0,单击右边绿色的Install1按钮安装：
• 结果如下
  

二、实验内容与主要步骤

提交点1：测试MyUtil类

• 实验要求
  • 参考 http://www.cnblogs.com/rocedu/p/6371315.html#SECUNITTEST
  • 参考http://www.cnblogs.com/rocedu/p/6736847.html
  • 提交最后三个测试用例都通过的截图，截图上要有画图加水印，输入自己的学号。
• 实验过程
  • 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”elsereturn "错误";}
  }

  • 测试代码

  import org.junit.Test;
  import junit.framework.TestCase;
  public class MyUtilTest extends TestCase {@Testpublic 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));}@Testpublic void testExceptions() {assertEquals("错误", MyUtil.percentage2fivegrade(-55));assertEquals("错误", MyUtil.percentage2fivegrade(105));}@Testpublic 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));}
  }

• 运行测试结果

提交点2：以TDD的方式研究学习StringBuffer

• 实验要求
  • 参考 积极主动敲代码，使用JUnit学习Java （http://www.cnblogs.com/rocedu/p/4837092.html)
  • 参考http://www.cnblogs.com/rocedu/p/6736847.html
  • 以 TDD的方式研究学习StringBuffer，提交你的单元测试用例和测试通过的截图，截图要加上学号水印。
• 实验过程
  • 产品代码

  public class StringBufferDemo {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("tring"));System.out.println("buffer = " + buffer.toString());System.out.println(buffer.length());}
  }

  • 测试代码

  import junit.framework.TestCase;
  import org.junit.Test;
  public class StringBufferDemoTest extends TestCase {StringBuffer a = new StringBuffer("StringBuffer");StringBuffer b = new StringBuffer("StringBufferStringBuffer");StringBuffer c = new StringBuffer("StringBufferStringBufferStringBuffer");@Testpublic void testcharAt() throws Exception {assertEquals('t', a.charAt(1));assertEquals('g', a.charAt(5));assertEquals('r', a.charAt(11));}@Testpublic void testcapacity() throws Exception {assertEquals(28, a.capacity());assertEquals(40, b.capacity());assertEquals(52, c.capacity());}@Testpublic void testlength() throws Exception {assertEquals(12, a.length());assertEquals(24, b.length());assertEquals(36, c.length());}@Testpublic void testindexOf() throws Exception {assertEquals(0, a.indexOf("Str"));assertEquals(5, b.indexOf("gBu"));assertEquals(8, c.indexOf("ffer"));}
  }

• 实验结果截图
  

提交点3：对设计模式示例进行扩充

• 实验要求
  • 参考http://www.cnblogs.com/rocedu/p/6736847.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
    • 用自己的学号%6进行取余运算，根据结果进行代码扩充：
    • 0： 让系统支持Byte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
    • 1： 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
    • 2： 让系统支持Boolean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
    • 3： 让系统支持Long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
    • 4： 让系统支持Float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
    • 5： 让系统支持Double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
• 实验代码

abstract class Data {abstract public void DisplayValue();
}
class Integer extends  Data {int value;Integer() {value=20175226%6;}public void DisplayValue(){System.out.println (value);}
}
class Byte extends  Data {byte value;Byte() {value=20175226%6;}public void DisplayValue(){System.out.println (value);}
}
class Short extends  Data {short value;Short() {value=20175226%6;}public void DisplayValue(){System.out.println (value);}
}
class Boolean extends  Data {boolean value;Boolean() {value=20175226%6==4;}public void DisplayValue(){System.out.println (value);}
}
class Long extends  Data {long value;Long() {value=20175226;}public void DisplayValue(){System.out.println (value);}
}
class Double extends  Data {double value;Double() {value=20175226%6;}public void DisplayValue(){System.out.println (value);}
}
class Float extends  Data {float value;Float() {value=20175226%6;}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 ByteFactory extends Factory {public Data CreateDataObject(){return new Byte();}
}
class ShortFactory extends Factory {public Data CreateDataObject(){return new Short();}
}
class BoolenFactory extends Factory {public Data CreateDataObject(){return new Boolean();}
}
class LongFactory extends Factory {public Data CreateDataObject(){return new Long();}
}
class DoubletFactory extends Factory {public Data CreateDataObject(){return new Double();}
}
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();}
}
//Test class
public class MyDoc {static Document d;public static void main(String[] args) {d = new Document(new IntFactory());d.DisplayData();d = new Document(new ByteFactory());d.DisplayData();d = new Document(new ShortFactory());d.DisplayData();d = new Document(new BoolenFactory());d.DisplayData();d = new Document(new LongFactory());d.DisplayData();d = new Document(new DoubletFactory());d.DisplayData();d = new Document(new FloatFactory());d.DisplayData();}
}

• 实验结果
  

提交点4：以TDD的方式开发一个复数类Complex

• 实验要求
  • 方式开发一个复数类Complex
• 代码要求

// 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 {// 定义属性并生成getter,setterdouble RealPart;double ImagePart;// 定义构造函数public Complex(){RealPart = 0;ImagePart = 1;}public Complex(double R,double I){ImagePart = I;RealPart = R;}//Override Objectpublic boolean equals(Object obj){if(this == obj) {return true;}if(!(obj instanceof Complex)) {return false;}Complex complex = (Complex) obj;if(complex.RealPart != ((Complex) obj).RealPart) {return false;}if(complex.ImagePart != ((Complex) obj).ImagePart) {return false;}return true;}public String toString()   {String string = "";if (ImagePart > 0)string =  RealPart + "+" + ImagePart + "i";if (ImagePart == 0)string =  RealPart + "";if (ImagePart < 0)string = RealPart + " " + ImagePart + "i";return string;}// 定义公有方法:加减乘除Complex ComplexAdd(Complex a) {double b=0,c=0;b = RealPart+a.RealPart;c = ImagePart+a.ImagePart;System.out.println("("+RealPart+"+"+ImagePart+"i) + ("+a.RealPart+"+"+a.ImagePart+") = "+b+"+"+c+"i");return  new Complex(b,c);}Complex ComplexSub(Complex a) {double b=0,c=0;b = RealPart-a.RealPart;c = ImagePart-a.ImagePart;System.out.println("("+RealPart+"+"+ImagePart+"i) - ("+a.RealPart+"+"+a.ImagePart+") = "+b+"+"+c+"i");return  new Complex(b,c);}Complex ComplexMulti(Complex a) {double b=0,c=0;b = RealPart*a.RealPart;c = ImagePart*a.ImagePart;System.out.println("("+RealPart+"+"+ImagePart+"i) * ("+a.RealPart+"+"+a.ImagePart+") = "+b+"+"+c+"i");return  new Complex(b,c);}Complex ComplexDiv(Complex a) {if(a.RealPart==0||a.ImagePart==0) {System.out.println("被除数不能为0，错误");return new Complex();}double d = Math.sqrt(a.RealPart*a.RealPart)+Math.sqrt(a.ImagePart*a.ImagePart);double b=0,c=0;b = (RealPart*a.RealPart+ImagePart*a.ImagePart)/d;c = Math.round((RealPart*a.ImagePart-ImagePart*a.RealPart)/d);System.out.println("("+RealPart+"+"+ImagePart+"i) / ("+a.RealPart+"+"+a.ImagePart+") = "+b+"+"+c+"i");return  new Complex(b,c);}
}

- 测试代码

import junit.framework.TestCase;
import org.junit.Test;
public class ComplexTest extends TestCase {Complex complex = new Complex(1, 1);@Testpublic void testAdd() {assertEquals(new Complex(3.0, 3.0), complex.ComplexAdd(new Complex(2.0, 2.0)));}@Testpublic void testSub() {assertEquals(new Complex(-5.0, -2.0), complex.ComplexSub(new Complex(6.0, 3.0)));}@Testpublic void testMulti() {assertEquals(new Complex(3.0, 2.0), complex.ComplexMulti(new Complex(3.0, 2.0)));}@Testpublic void testDiv() {assertEquals(new Complex(1.0, 1.0), complex.ComplexDiv(new Complex(1.0, 1.0)));assertEquals(new Complex(0.0, 0.0), complex.ComplexDiv(new Complex(1.0, 0.0)));//边缘测试}
}

• 结果截图
  

提交点5：类图

实验中碰到的问题

• 问题1：在第二个提交点写测试类时，测试charAt方法时我写的语句是

public void testcharAt() throws Exception {assertEquals("t", a.charAt(1));assertEquals("g", a.charAt(5));assertEquals("r", a.charAt(11));}

结果发现怎么样测试都是红色条，不通过。

• 问题1解决过程：经过反复测试我将测试的代码换成了下面这样才能通过

    public void testcharAt() throws Exception {assertEquals('t', a.charAt(1));assertEquals('g', a.charAt(5));assertEquals('r', a.charAt(11));}

这个问题体现了一些我们的细节，像两个字符串比较一样，虽然" s "和' s '看起来内容一模一样但事实上两者比较起来两者之间有很大差异。两者占用的内存空间就不一样至少会有"\0".所以显而易见字符可以被视为长度为1的字符串这个想法是错误的。

(代码托管)[https://gitee.com/wpyzka/20175226/tree/master/src/shiyan2]