20165317JAVA实验二-面向对象程序设计

JAVA实验二-面向对象程序设计

提交点一

在IDEA中建立名为MyUtil5317的project，并在其src文件夹中创建名为MyUtil5317的public类，并输入如下代码。

public class MyUtil5317{
    public static String percentage2fivegrade(int grade){
        if (grade < 60 && grade >= 0 )
            return "不及格";
        else if (grade < 70 && grade >= 0 )
            return "及格";
        else if (grade < 80 && grade >= 0 )
            return "中等";
        else if (grade < 90 && grade >= 0 )
            return "良好";
        else if (grade <= 100 && grade >= 0 )
            return "优秀";
        else
            return "错误";
    }
}

在项目根目录下建立名为test的子目录，并将其设定为test的源代码存放目录，在目录中建立测试源代码，并按照Intellj IDEA 简易教程-单元测试的要求进行操作，其中代码如下：

import org.junit.Test;
import junit.framework.TestCase;
public class MyUtil5317Test extends TestCase {
    @Test
    public void testNormal() {
        assertEquals("不及格", MyUtil5317.percentage2fivegrade(55));
        assertEquals("及格", MyUtil5317.percentage2fivegrade(65));
        assertEquals("中等", MyUtil5317.percentage2fivegrade(75));
        assertEquals("良好", MyUtil5317.percentage2fivegrade(85));
        assertEquals("优秀", MyUtil5317.percentage2fivegrade(95));
    }

    @Test
    public void testException() {
        assertEquals("错误", MyUtil5317.percentage2fivegrade(-5));
        assertEquals("错误", MyUtil5317.percentage2fivegrade(105));
    }

    @Test
    public void testBoundary() {
        assertEquals("不及格", MyUtil5317.percentage2fivegrade(0));
        assertEquals("及格", MyUtil5317.percentage2fivegrade(60));
        assertEquals("中等", MyUtil5317.percentage2fivegrade(70));
        assertEquals("良好", MyUtil5317.percentage2fivegrade(80));
        assertEquals("优秀", MyUtil5317.percentage2fivegrade(90));
        assertEquals("优秀", MyUtil5317.percentage2fivegrade(100));
    }
}

结果截图如下

提交点二

参考积极主动敲代码，使用JUnit学习Java，以 TDD的方式研究学习StringBuffer。

按照上述博客和第一提交点完成代码的编辑

public class StringBufferDemo{
    public static void main(String [] args){
        StringBuffer buffer = new StringBuffer();
        buffer.append('S');
        buffer.append("tringBuffer12345");
        System.out.println(buffer.charAt(1));
        System.out.println(buffer.capacity());
        System.out.println(buffer.indexOf("tringBuffer12345"));
        System.out.println("buffer = " + buffer.toString());
        System.out.println(buffer.length());
    }
}

编辑测试用例如下

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

public class StringBufferDemotest extends TestCase {
    StringBuffer jh = new StringBuffer("nxy and jh");
    StringBuffer nxy = new StringBuffer("nxy and jh danthony nb");
    public void testcharat() {
        assertEquals('n', jh.charAt(0));
        assertEquals('n', nxy.charAt(0));
    }
    public void testcapacity() {
        assertEquals(26, jh.capacity());
        assertEquals(38, nxy.capacity());
    }
    public void testlength() {
        assertEquals(10, jh.length());
        assertEquals(22, nxy.length());
    }
    public void testindexof() {
        assertEquals(0, jh.indexOf("nxy"));
        assertEquals(20,nxy.indexOf("nb"));
    }
}

提交的结果截图

提交点三

实验题目：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=100;
    }
    public void DisplayValue(){
        System.out.println (value);
    }
}
class Short extends Data {
    short value;
    Short() {
        value = 5317;
    }
    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 ShortFactory extends Factory {
    public Data CreateDataObject(){
        return new Short();
    }
}

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 ShortFactory());
        d.DisplayData();
    }
}

结果运行截图

提交点四

任务：以TDD的方式开发一个复数类Complex
- 定义属性并生成getter,setter
- double RealPart;
- double ImagePart
实验代码

public class Complex {
    double R;
    double I;

    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 str = "";
        if (I > 0)
            str = R + "+" + I + "i";
        if (I == 0)
            str = R+"";
        if (I < 0)
            str = R + "" + I + "i";
        return str;
    }
    public boolean equals(Object obj){
        if (this == obj)
            return true;
        if(obj==null)
            return false;
        if(obj instanceof Complex){
            Complex p = (Complex) obj;
            if(p.R==this.R &&p.I==this.I )
                return true;
        }
        return false;
    }
}

调试代码如下

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

public class ComplexTest extends TestCase {
    Complex c1 = new Complex(1.0,2.0);
    Complex c2 = new Complex(2.0,2.0);
    Complex c3 = new Complex(2.0,0.0);
    @Test
    public void testGetRealPart() throws Exception {
        assertEquals(-1.1, Complex.getRealPart(-1.1));
        assertEquals(6.0, Complex.getRealPart(6.0));
        assertEquals(0.0, Complex.getRealPart(0.0));
    }

    @Test
    public void testGetImagePart() throws Exception {
        assertEquals(-1.1, Complex.getImagePart(-1.1));
        assertEquals(6.0, Complex.getImagePart(6.0));
        assertEquals(0.0, Complex.getImagePart(0.0));
    }

    @Test
    public void testComplexAdd() throws Exception {
        assertEquals("3.0+4.0i", c1.ComplexAdd(c2).toString());
        assertEquals("3.0+2.0i", c1.ComplexAdd(c3).toString());
        assertEquals("4.0+2.0i", c2.ComplexAdd(c3).toString());
    }

    @Test
    public void testComplexSub() throws Exception {
        assertEquals("-1.0", c1.ComplexSub(c2).toString());
        assertEquals("-1.0+2.0i", c1.ComplexSub(c3).toString());
        assertEquals("0.0+2.0i", c2.ComplexSub(c3).toString());
    }

    @Test
    public void testComplexMulti() throws Exception {
        assertEquals("-2.0+6.0i", c1.ComplexMulti(c2).toString());
        assertEquals("2.0+4.0i", c1.ComplexMulti(c3).toString());
        assertEquals("4.0+4.0i", c2.ComplexMulti(c3).toString());
    }

    @Test
    public void testComplexComplexDiv() throws Exception {
        assertEquals("0.75+0.75i", c1.ComplexDiv(c2).toString());
        assertEquals("1.0+0.5i", c1.ComplexDiv(c3).toString());
        assertEquals("1.0+1.0i", c2.ComplexDiv(c3).toString());
    }
    @Test
    public void testEquals() throws Exception{
        assertEquals(false,c1.equals(c2));
        assertEquals(false,c1.equals(c3));
        assertEquals(false,c2.equals(c3));
        assertEquals(true,c1.equals(c1));
    }

}