2017-2018-2 20165312實驗二《Java面向對象程序設計》實驗報告

2017-2018-2 20165312實驗二《Java面向對象程序設計》實驗報告

實驗中遇到的問題

1.增長MyUtil的測試類以後，TestCase是紅色的，可是沒有找到junit.jar包的地方

解決方法：

• 找到電腦中IDEA安裝路徑

• 打開File->Project Structure
• 點擊Dependencies,單擊右上角的+,而後選擇第一個JARs or directories
• 複製剛纔的路徑名，找到junit-4.12 jar、 junit.jar

• 選擇junit-4.12 jar、 junit.jar兩項，並點擊下方Ok

2.在作第二個實驗的時候，運行測試代碼時出現了問題

並非產品代碼的問題，而是測試代碼的問題。

@Test
public void testcharAt(){
    assertEquals("S",buffer.charAt(0));
    }
@Test
public void testcapacity(){
    assertEquals("28",buffer.capacity());
    
}
@Test
public void testindexof(){
    assertEquals("1",buffer.indexOf("tring"));
}

"S" "28" 「1」是錯誤的

正確代碼：

@Test
public void testcharAt(){
    assertEquals('S',buffer.charAt(0));
}
@Test
public void testcapacity(){
    assertEquals(28,buffer.capacity());
}
@Test
public void testindexof(){
    assertEquals(1,buffer.indexOf("tring"));
}

知識點總結

• 僞代碼
• 產品代碼
  • Java編程時，程序員對類實現的測試叫單元測試。
  • 測試用例是爲某個特殊目標而編制的一組測試輸入、執行條件以及預期結果，以便測試某個程序路徑或覈實是否知足某個特定需求。
• 先寫測試代碼，而後再寫產品代碼的開發方法叫「測試驅動開發」（TDD）
• 面向對象三要素是「封裝、繼承、多態」，任何面向對象編程語言都會在語法上支持這三要素。S.O.L.I.D類設計原則：
  • SRP(Single Responsibility Principle,單一職責原則)
  • OCP(Open-Closed Principle,開放-封閉原則)
  • LSP(Liskov Substitusion Principle,Liskov替換原則)
  • ISP(Interface Segregation Principle,接口分離原則)
  • DIP(Dependency Inversion Principle,依賴倒置原則)

五項實驗任務

1、學生成績等級制

題目要求：測試用例（正常狀況，錯誤狀況，邊界狀況）都經過

產品代碼：

/**
 * Created by CaoGe on 2018/4/14.
 */
public class MyUtil{
    public static String percentage2fivegrade(int grade){
        //若是成績小於0，轉成「錯誤」
        if ((grade < 0))
            return "錯誤";
            //若是成績小於60，轉成「不及格」
        else if (grade < 60)
            return "不及格";
            //若是成績在60與70之間，轉成「及格」
        else if (grade < 70)
            return "及格";
            //若是成績在70與80之間，轉成「中等」
        else if (grade < 80)
            return "中等";
            //若是成績在80與90之間，轉成「良好」
        else if (grade < 90)
            return "良好";
            //若是成績在90與100之間，轉成「優秀」
        else if (grade <= 100)
            return "優秀";
            //若是成績大於100，轉成「錯誤」
        else
            return "錯誤";
    }
}

測試代碼：

import junit.framework.TestCase;
import org.junit.Test;
/**
 * Created by CaoGe on 2018/4/14.
 */
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("優秀", MyUtil.percentage2fivegrade(95));

    }
    @Test
    public void testException(){
        assertEquals("不及格",MyUtil.percentage2fivegrade(55));
        assertEquals("不及格",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("優秀",MyUtil.percentage2fivegrade(90));
        assertEquals("優秀",MyUtil.percentage2fivegrade(100));
    }
}

運行截圖：

#### 2、TDD的方式研究學習StringBuffer

產品代碼：

public class StringBufferExercise {
    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());
    }
}

測試代碼：

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

public class StringBufferExerciseTest extends TestCase {
    StringBuffer buffer = new StringBuffer("StringBuffer");
    @Test
    public void testcharAt(){
        assertEquals('S',buffer.charAt(0));
    }
    @Test
    public void testcapacity(){
        assertEquals(28,buffer.capacity());
    }
    @Test
    public void testindexof(){
        assertEquals(1,buffer.indexOf("tring"));
    }
    @Test
    public void testtoString(){
        assertEquals("StringBuffer",buffer.toString());
    }
}

運行截圖：

3、體會OCP原則和DIP原則的應用

題目要求：讓系統支持Byte類，並在MyDoc類中添加測試代碼代表添加正確。

產品代碼以下：

import java.util.Objects;
abstract class Data {
    abstract public void DisplayValue();
}
class Byte extends Data {
    byte value1;
    byte value2;
    Byte() {
        value1=53;
        value2=12;
    }
    public void DisplayValue(){
        System.out.println (value1);
        System.out.println (value2);
    }
}
// Pattern Classes
abstract class Factory {
    abstract public Data CreateDataObject();
}
class ByteFactory extends Factory {
    public Data CreateDataObject(){
        return new Byte();
    }
}
//Client classes
class Document {
    Data data;
    Document(Factory factory){
        data = factory.CreateDataObject();
    }
    public void DisplayData(){
        data.DisplayValue();

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

運行截圖以下：

4、以TDD的方式開發一個複數類Complex

要求以下：

// 定義屬性並生成getter,setter
double RealPart;
double ImagePart;
// 定義構造函數
public Complex()
public Complex(double R,double I)

//Override Object
public boolean equals(Object obj)
public String toString()

// 定義公有方法:加減乘除
Complex ComplexAdd(Complex a)
Complex ComplexSub(Complex a)
Complex ComplexMulti(Complex a)
Complex ComplexDiv(Complex a)

產品代碼：

public class Complex{
    private double r;
    private double i;

    public Complex(double r, double i) {
        this.r = r;
        this.i = i;
    }

    public static double getRealPart(double r) {
        return r;
    }

    public static double getImagePart(double i) {
        return i;
    }

    public Complex ComplexAdd(Complex c) {
        return new Complex(r + c.r, i + c.i);
    }
    public Complex ComplexSub(Complex c) {
        return new Complex(r - c.r, i - c.i);
    }
    public Complex ComplexMulti(Complex c) {
        return new Complex(r * c.r - i * c.i, r * c.i + i * c.r);
    }
    public Complex ComplexDiv(Complex c) {
        return new Complex((r * c.i + i * c.r)/(c.i * c.i + c.r * c.r), (i * c.i + r * c.r)/(c.i * c.i + c.r * c.r));
    }

    public String toString() {
        String s = " ";
        if (i > 0)
            s =  r + "+" + i + "i";
        if (i == 0)
            s =  r + "";
        if (i < 0)
            s = r + " " + i + "i";
        return s;
    }
}

測試代碼：

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

public class ComplexTest extends TestCase {
    Complex c1 = new Complex(0, 3);
    Complex c2 = new Complex(-1, -1);
    Complex c3 = new Complex(2,1);
    @Test
    public void testgetRealPart() throws Exception {
        assertEquals(-1.0, Complex.getRealPart(-1.0));
        assertEquals(5.0, Complex.getRealPart(5.0));
        assertEquals(0.0, Complex.getRealPart(0.0));
    }
    @Test
    public void testgetImagePart() throws Exception {
        assertEquals(-1.0, Complex.getImagePart(-1.0));
        assertEquals(5.0, Complex.getImagePart(5.0));
        assertEquals(0.0, Complex.getImagePart(0.0));
    }
    @Test
    public void testComplexAdd() throws Exception {
        assertEquals("-1.0+2.0i", c1.ComplexAdd(c2).toString());
        assertEquals("2.0+4.0i", c1.ComplexAdd(c3).toString());
        assertEquals("1.0", c2.ComplexAdd(c3).toString());
    }
    @Test
    public void testComplexSub() throws Exception {
        assertEquals("1.0+4.0i", c1.ComplexSub(c2).toString());
        assertEquals("-2.0+2.0i", c1.ComplexSub(c3).toString());
        assertEquals("-3.0 -2.0i", c2.ComplexSub(c3).toString());
    }
    @Test
    public void testComplexMulti() throws Exception {
        assertEquals("3.0 -3.0i", c1.ComplexMulti(c2).toString());
        assertEquals("-3.0+6.0i", c1.ComplexMulti(c3).toString());
        assertEquals("-1.0 -3.0i", c2.ComplexMulti(c3).toString());
    }
    @Test
    public void testComplexComplexDiv() throws Exception {
        assertEquals("-1.5 -1.5i", c1.ComplexDiv(c2).toString());
        assertEquals("1.2+0.6i", c1.ComplexDiv(c3).toString());
        assertEquals("-0.6 -0.6i", c2.ComplexDiv(c3).toString());
    }
}

運行截圖：

5、使用StarUML對實驗二中的代碼進行建模

我對第三個實驗畫了UML圖

步驟	耗時	百分比
需求分析	2h	16%
設計	1h	8%
代碼實現	2h	16%
測試	2h	16%
分析總結	3h	25%