20175214 实验二面向对象程序设计

一、前期准备

1. 熟悉三种代码的编写
- 伪代码
- 产品代码
- 测试代码
1. 学会 IDEA中配置单元测试工具JUnit
- 打开IDEA，选择File->Setting打开设置对话框
- 在设置对话框中选择Plugins, 单击Marketplace
- 选择JUnitGenerator V2.0,点击Install安装
- 安装好后可以在Installed里查看
- 安装完成后，要开始配置。在IDEA中新建一个项目，然后新建一个空类MyUtil:
- 鼠标右击类名，选择go to->test->Create New Test
- 弹出一个对话框，选择JUnit3
- 输入时junit可能会标红，可以双击标红处，点击红色灯泡导入需要的类。

二、实验内容

任务一：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。
任务二：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。
任务三：
- 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。
任务四：以TDD的方式开发一个复数类Complex。
任务五：
- 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。
- 类图中至少两个类。
- 类，继承，接口实现，组合在UML中表达。

三、实验步骤

任务一

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 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(105));
        }
        @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));
        }
    }

测试结果截图：

任务二

产品代码

 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

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

import static org.junit.Assert.*;

public class StringBufferDemoTest extends TestCase {

    StringBuffer a = new StringBuffer("StringBuffer");
    StringBuffer b = new StringBuffer("StringBufferStringBuffer");
    StringBuffer c = new StringBuffer("StringBufferStringBufferStringBuffer");

    @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());//验证字符串a的长度
        assertEquals(24, b.length());
        assertEquals(36, c.length());
    }

    @Test
    public void testindexOf() {
        assertEquals(6, a.indexOf("Buff"));
        assertEquals(5, b.indexOf("gBu"));
        assertEquals(10, c.indexOf("erS"));
    }
}

测试结果截图：

任务三

产品代码

 // Server Classes 
abstract class Data {
  abstract public void DisplayValue();
}
class Integer extends  Data {
  int value;
  Integer() {
      value=100;
  }
  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();
  }
}
//Client classes 
class Document {
  Data pd;
  Document(Factory pf){
      pd = pf.CreateDataObject();
  }
  public void DisplayData(){
      pd.DisplayValue();
  }
}
class Boolean extends  Data {
  boolean flag;
  Boolean() {
      flag=true;
  }
  public void DisplayValue(){
      System.out.println (flag);
  }
}
class BooleanFactory extends Factory {
  public Data CreateDataObject() {
      return new Boolean();
  }
}
//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 BooleanFactory());
      d.DisplayData();
  }
}

测试结果截图

任务四
- 产品代码

public class Complex {
    double RealPart;
    double ImagePart;

    public Complex() {
    }

    public Complex(double R, double I) {
        RealPart = R;
        ImagePart = I;
    }

    public boolean equals(Complex a) {
        if (a.RealPart == this.RealPart && a.ImagePart == this.ImagePart) {
            return true;
        } else {
            return false;
        }
    }

    public String toString() {
        if (this.RealPart != 0 && this.ImagePart > 0) {
            return this.RealPart + " + " + this.ImagePart + "i";
        } else if (this.RealPart != 0 && this.ImagePart == 0) {
            return String.valueOf(this.RealPart);
        } else if (this.RealPart != 0 && this.ImagePart < 0) {
            return this.RealPart + " - " + -this.ImagePart + "i";
        } else if (this.RealPart == 0 && this.ImagePart != 0) {
            return this.ImagePart + "i";
        } else {
            return "0";
        }
    }

    Complex ComplexAdd(Complex a) {
        return new Complex(this.RealPart + a.RealPart, this.ImagePart + a.ImagePart);
    }

    Complex ComplexSub(Complex a) {
        return new Complex(this.RealPart - a.RealPart, this.ImagePart - a.ImagePart);
    }

    Complex ComplexMulti(Complex a) {
        return new Complex(this.RealPart * a.RealPart - this.ImagePart * a.ImagePart,
                this.ImagePart * a.RealPart + this.RealPart * a.ImagePart);
    }

    Complex ComplexDiv(Complex a) {
        return new Complex((this.ImagePart * a.ImagePart + this.RealPart * a.RealPart) / (a.ImagePart * a.ImagePart + a.RealPart * a.RealPart), (this.RealPart * a.ImagePart - this.ImagePart * a.RealPart) / (a.ImagePart * a.ImagePart + a.RealPart * a.RealPart));
    }

}

测试代码

import junit.framework.TestCase;

public class ComplexTest extends TestCase {
    Complex a = new Complex(3.0, 4.0);
    Complex b = new Complex(-2.0, -3.0);

    public void testEquals() {
        assertEquals(true, a.equals(a));
        assertEquals(false, b.equals(a));
    }

    public void testToString() {
        assertEquals("3.0 + 4.0i", a.toString());
        assertEquals("-2.0 - 3.0i", b.toString());
    }

    public void testComplexAdd() {
        assertEquals("1.0 + 1.0i",a.ComplexAdd(b).toString());
        assertEquals("-4.0 - 6.0i",b.ComplexAdd(b).toString());
    }

    public void testComplexSub() {
        assertEquals("5.0 + 7.0i",a.ComplexSub(b).toString());
        assertEquals("0",b.ComplexSub(b).toString());
    }

    public void testComplexMulti() {
        assertEquals("-7.0 + 24.0i",a.ComplexMulti(a).toString());
        assertEquals("6.0 - 17.0i",a.ComplexMulti(b).toString());
    }

    public void testComplexDiv() {
        assertEquals("1.0",a.ComplexDiv(a).toString());
    }
}