一、前期准备： unit的安装与使用： 打开idea，Preferences中点击Plugins，在market中搜索junit，如图点选JUnitGenerator V2.0进行安装，安装后会显示installed。
新建立的文件可以点击小灯泡，建立test文件，或者选中类名，Go to>test，新建test文件并勾选要测试的方法即可 点击File——>Progect------->Dependencies导入包。
二、实验步骤： 任务一：在一个MyUtil类中解决一个百分制成绩转成“优、良、中、及格、不及格”五级制成绩的功能。 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60，转成“不及格” if (grade<60&&grade>=0) return "不及格"; //如果成绩在60与70之间，转成“及格” else if (grade < 70&&grade>=60) return "及格"; //如果成绩在70与80之间，转成“中等” else if (grade < 80&&grade>=70) return "中等"; //如果成绩在80与90之间，转成“良好” else if (grade < 90&&grade>=80) return "良好"; //如果成绩在90与100之间，转成“优秀” else if (grade <= 100&&grade>=90) return "优秀"; //其他，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 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)); } } ```
结果截图
任务二：以TDD的方式研究学习StringBuffer
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.*; // 20175308 public class StringBufferDemoTest extends TestCase { StringBuffer a = new StringBuffer("StringBuffer"); StringBuffer b = new StringBuffer("StringBufferStringBuffer"); StringBuffer c = new StringBuffer("StringBuffer tested by 175308"); @Test public void testCharAt() throws Exception{ assertEquals('S',a.charAt(0));//验证返回是否是整个字符串中的第一个字符 assertEquals('g',b.charAt(5));//验证返回是否是整个字符串的第六个字符 assertEquals('t',c.charAt(16)); } @Test public void testcapacity() throws Exception{// assertEquals(28,a.capacity()); assertEquals(40,b.capacity()); assertEquals(45,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(29,c.length()); } @Test public void testindexOf(){ assertEquals(6,a.indexOf("Buff")); assertEquals(3,b.indexOf("ing")); assertEquals(23,c.indexOf("1753")); } } ``` 结果截图：
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，初步理解设计模式
依据OCP原则和DIP原则，
在扩充示例使其支持Boolean类时不应该直接添加或修改已有类中的方法（OCP原则要求软件实体对修改封闭），
而是采用一种抽象工厂的方法来进行对于程序的扩充。
具体代码如下： ```
abstract class Data { abstract public void DisplayValue(); } class Integer extends Data { int value; Integer() { value=100; } public void DisplayValue(){ System.out.println (value); } } class Boolean extends Data{ boolean value; Boolean(){ value=true; } 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 BooleanFactory extends Factory{ public Data CreateDataObject(){ return new Boolean(); } } class Document { Data pd; Document(Factory pf){ pd = pf.CreateDataObject(); } public void DisplayData(){ pd.DisplayValue(); } } //Test class 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 BooleanFactory()); e.DisplayData();
} } ```
运行成功截图：
任务四：以TDD的方式开发一个复数类Complex 之前没有做过结对项目因此没有对定义分数类的经验，使得我查了好多东西才解决，这对于复数类的定义也是一个好的锻炼。 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) ```
测试代码： ```
import org.junit.Test; import junit.framework.TestCase; public class ComplexTest extends TestCase { Complex a =new Complex(3.0,4.0); Complex b =new Complex( 2.0,-4.0); Complex c =new Complex(0.0,0.0); Complex d =new Complex(-3.0,0.0); Complex e =new Complex(-6.0,-0.8); @Test public void testgetRealPart()throws Exception{ assertEquals(3.0,a.getRealPart()); assertEquals(2.0,b.getRealPart()); assertEquals(0.0,c.getRealPart()); assertEquals(-3.0,d.getRealPart()); assertEquals(-6.0,e.getRealPart()); } @Test public void testgetImagePart()throws Exception{ assertEquals(4.0,a.getImagePart()); assertEquals(-4.0,b.getImagePart()); assertEquals(0.0,c.getImagePart()); assertEquals(0.0,d.getImagePart()); assertEquals(0.8,e.getImagePart());
} @Test public void testtoString()throws Exception{ assertEquals("3.0+4.0i",a.toString()); assertEquals("2.0-4.0i",b.toString()); assertEquals("0",c.toString()); assertEquals("-3.0",d.toString()); assertEquals("-6.0-8.0i",e.toString()); } @Test public void testComplexAdd()throws Exception{ assertEquals("5.0",a.ComplexAdd(b).toString()); assertEquals("2.0-4.0i",b.ComplexAdd(c).toString()); assertEquals("-1.0-4.0i",b.ComplexAdd(d).toString()); } @Test public void testComplexSub()throws Exception{ assertEquals("1.0+8.0i",a.ComplexSub(b).toString()); assertEquals("-2.0+4.0i",c.ComplexSub(b).toString()); assertEquals("3.0",c.ComplexSub(d).toString()); } @Test public void testComplexMulti()throws Exception{ assertEquals("22.0-4.0i",a.ComplexMulti(b).toString()); assertEquals("0",b.ComplexMulti(c).toString()); assertEquals("18.0+2.4i",d.ComplexMulti(e).toString()); } @Test public void testComplexDiv()throws Exception{ assertEquals("-0.2-1.25i",a.ComplexDiv(b).toString()); assertEquals("0",c.ComplexDiv(b).toString()); } @Test public void testequals()throws Exception{ assertEquals(true,a.equals(a)); assertEquals(false,a.equals(b));
}
} ```
产品代码： ```
import com.sun.jdi.DoubleValue; import java.util.zip.CheckedOutputStream; import java.text.DecimalFormat;
public class Complex { double RealPart=0; double ImagePart=0; public Complex(){} public Complex(double RealPart,double ImagePart){ this.RealPart=RealPart; this.ImagePart=ImagePart;
} public double getRealPart(){ return RealPart; } public double getImagePart(){ return ImagePart; } public String toString(){ String s = ""; double r=RealPart; double i=ImagePart; if(r==0&&i==0){ s="0"; } else if(r==0&&i!=0){ s=i+"i"; } else if(r!=0&&i<0){ s=r+""+i+"i"; } else if(r!=0&&i==0){ s=r+""; } else { s=r+"+"+i+"i"; } return s; } public boolean equals(Object obj){ if(this==obj){ return true; } else return false; } DecimalFormat df = new DecimalFormat( "0.0"); 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){ double r=RealPart*a.getRealPart()-ImagePart*a.getImagePart(); double i =ImagePart*a.getRealPart()+RealPart*a.getImagePart(); return new Complex(Double.valueOf(df.format(r)),Double.valueOf(df.format(i))); } public Complex ComplexDiv(Complex a){ double r=(RealPart * a.ImagePart + ImagePart * a.RealPart) / (a.ImagePart * a.ImagePart + a.RealPart * a.RealPart); double i=(ImagePart * a.ImagePart + RealPart * a.RealPart) / (a.RealPart * a.RealPart + a.RealPart * a.RealPart); return new Complex(Double.valueOf(df.format(r)),Double.valueOf(df.format(i))); }
} ```
测试成功截图：
任务五：对实验二中的代码进行建模 任务要求类图中至少要有两个类，符合要求的是MyDoc.java的代码，UML图如下：
实验中遇到的问题及解决：
1.下载Junit后仍然出现标红无法使用。
在File菜单栏找到Project Structure
将包勾选好
