[ST2017] Lab1: Triangle type and Junit test

Lab1 3014218071 王汉超

Request:

  Write a program with a function(getTriangleStatus) and test it, which takes three double number l1, l2, l3 as lengths of triangle sides and calculates whether the triangle is equilateral, isosceles, or scalene.

Contents:

一. 导入相应包

1.导入 JUnit, Hamcrest

右键项目名 -> 选择 属性Properties -> 选择 Libraries -> 选择 JUnit4 -> Finish

2. 导入

Help -> Install new software -> Add -> Local -> 选择本地文件Eclemma路径 -> 安装, 安装后重启.

二、实验内容

1.Description

    判断三角形类型的程序:

    Input 三条边的长度(double): l1, l2, l3

    Output 构成三角形类型(int): 1 -- 错误(边长不是正实数); 0 -- 不构成三角形, 1 -- 非等腰(scalene)三角形, 2 -- 等腰不等边(isosceles)三角形, 3 -- 等边(equilateral)三角形

2.Codes:

gitHub: https://github.com/E-C-Ares/ST2017_Lab1

Main.java:

package isTriangle;

import java.util.Scanner;

public class Main {
    public static int getTriangleStatus(double l1, double l2, double l3)
    {
        int s = -1;
        double temp = 0;
        
        //l1 > l2 > l3
        if (l2 > l1){
            temp = l2;
            l2 = l1;
            l1 = temp;
        }
        if (l3 > l1){
            temp = l3;
            l3 = l1;
            l1 = temp;
        }
        if (l3 > l2){
            temp = l3;
            l3 = l2;
            l2 = temp;
        }
        
        if(l3 > 0){
            if(l1 >= l2 + l3)
            {
                s = 0;
            }
            else if(l1 < l2 + l3){
                s = 1;
                if(l1 == l2 || l2 == l3)
                {
                    s ++;
                    if(l1 == l3)
                    {
                        s ++;
                    }
                }
            }
        }
        return s;
    }
    
    @SuppressWarnings("resource")
    public static void main(String[] args){
        Scanner edges = new Scanner(System.in);
        System.out.println("输入三条边的长度："); 
        double l1 = edges.nextDouble();      
        double l2 = edges.nextDouble();
        double l3 = edges.nextDouble();
        int s = getTriangleStatus(l1, l2, l3);
        switch (s){
        case -1:
            System.out.println("输入不符合要求"); 
            break;
        case 0:
            System.out.println("不构成三角形");
            break;
        case 1:
            System.out.println("一般三角形");
            break;
        case 2:
            System.out.println("仅等腰三角形");
            break;
        case 3:
            System.out.println("等边三角形");
            break;
        }
        main(args);
    }
}

3.JUnit Test & Eclemma Cover:

    为了避免污染源代码, 测试代码和源代码放置于不同的文件夹中:

    右键项目 -> New -> JUnit Test Case -> 选择被测试函数: 截图如下:

MainTest.java:

package isTriangle;

import static org.junit.Assert.*;

import org.junit.Test;


public class MainTest {

    Main t= new Main();
    //getTriangleStatus getStatus = new getTriangleStatus();
    
    @Test
    public void test1() {
        assertEquals("Should be an equilateral triangle", 3, t.getTriangleStatus(1.0, 1.0, 1.0));
    }
    
    @Test
    public void test2() {
        assertEquals("Should be an ERROR!", -1, t.getTriangleStatus(0, 0, 0));
    }
    
    @Test
    public void test3() {
        assertEquals("Should be an ERROR!", -1, t.getTriangleStatus(0, 1, 1));
    }
    
    @Test
    public void test4() {
        assertEquals("Should be an ERROR!", -1, t.getTriangleStatus(-0.01, 9.0, 9.0));
    }
    
    @Test
    public void test5() {
        assertEquals("Should be an isosceles triangle", 2, t.getTriangleStatus(2, 2, 3));
    }
    
    @Test
    public void test6() {
        assertEquals("Should be an isosceles triangle", 0, t.getTriangleStatus(1, 1, 2));
    }
    
    @Test
    public void test7() {
        assertEquals("Should be a scalene triangle", 1, t.getTriangleStatus(10.0000, 10.0001, 10.0002));
    }
    
    @Test
    public void test8() {
        assertEquals("Should be a scalene triangle", 1, t.getTriangleStatus(10.0000, 10.0001, 10.0002));
    }
    
    @Test
    public void test9() {
        assertEquals("Should be a scalene triangle", 1, t.getTriangleStatus(10.0000, 10.0001, 10.0002));
    }
    
    @Test
    public void test10() {
        assertEquals("Should be a scalene triangle", 1, t.getTriangleStatus(10.0000, 10.0001, 10.0002));
    }
    
    @Test
    public void test11() {
        assertEquals("Should be a scalene triangle", 1, t.getTriangleStatus(10.0, 9.0, 8.0));
    }    
}

Run -> Coverage last launched

三. 实验结果

Junit 测试用例 与 Eclemma 覆盖检测:

四. 总结

学会了安装jar包, 使用 JUnit 和 Eclemma 进行测试, 习得在测试的过程中应该考虑到尽可能多的情况, 以满足程序的完备性.