使用junit4进行参数化测试

参数化测试主要解决一次性进行多个测试用例的测试。其主要思想是，将多个测试用例按照，{输入值，输出值}（输入值可以是多个）的列表方式进行测试。
本文使用的是Eclipse+Junit4进行测试。之所以使用Eclipse+Junit4而不是使用Idea+Junit5的环境。是因为Eclipse+junit4环境能够轻易生成ant自动化测试报告。（关于自动化测试报告后面进行讲述）

主要看PeopleTestParameterized.java文件

项目结构

Clothes.java

package barry;

public abstract class Clothes {
    public abstract double getprice();
}

Cap.java

package barry;

public class Cap extends Clothes{
	public double C_price;
	public double C_discout;
	public int Discount;

    Cap(double price, double discout, int Dis){
        C_price = price;
        C_discout = discout;
        Discount = Dis;
    }
    
    
    @Override
    public double getprice() {
        double Price;

        if(Discount==1){
            Price = C_price*(1-C_discout);
        }else{
            Price = C_price;
        }
        return Price;
    }

}

Jacket.java

package barry;

public class Jacket extends Clothes{
    public double J_price;
    public double J_discout;
    public int Discount;

    Jacket(double price, double discount, int Dis){
        J_price = price;
        J_discout = discount;
        Discount = Dis;
    }
    
    
 
    @Override
    public double getprice() {
        double Price;
        if(Discount==1){
            Price = J_price*(1-J_discout);
        }else{
            Price = J_price;
        } 
        return Price;
    }

}

Trousers.java

package barry;

public class Trousers extends Clothes{
	public double T_price;
	public double T_discount;
	public int Discount;

    Trousers(double price, double discount, int Dis){
        T_price = price;
        T_discount = discount;
        Discount = Dis;
    }
 
    @Override
    public double getprice() {
        double Price;
        if(Discount==1){
            Price = T_price*(1-T_discount);
        }else{
            Price = T_price;
        }
        return Price;
    }
}

People.java

package barry;

public class People {
    public Clothes cap;
    public Clothes jacket;
    public Clothes trousers;
    
    
    People(){}
    
    People(Clothes cap, Clothes jacket,Clothes trousers){
        this.cap = cap;
        this.jacket = jacket;
        this.trousers = trousers;
    }
    

    public double getAllprice(){
        double Price=0;
        Price+= cap.getprice();
        Price+= jacket.getprice();
        Price+= trousers.getprice();
        return Price;
    }
    
    public void clear() {
    	this.cap = null;
    	this.jacket = null;
    	this.trousers = null;
    }
    
    	
    public void timetest() {
    	for(int i = 0; i < 100;i++) {
    	}
    }
}

PeopleTestParameterized.java

package barry;

import static org.junit.Assert.*;

import java.util.Arrays;
import java.util.Collection;
import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;


//表示使用参数化测试的方法
@RunWith(Parameterized.class)
public class PeopleTestParameterized {
	
	private People param;
	private double result;
	
	
	@Before
	public void setUp() {
		People people = new People();
	}
	
	@After
	public void tearDown() {
		
	}
	
	
	//测试用例使用Collection数据类型返回
	@Parameters
	public static Collection data() {
		
		Cap cap = new Cap(1999,0.1,0);
		Jacket jacket = new Jacket(2999,0.2,1);
		Trousers trousers = new Trousers(7999,0.1,1);
		People p_1 = new People(cap,jacket,trousers);
		double re_1 = PeopleTest.cal(cap, jacket, trousers);
		
		
		cap = new Cap(19999,0.1,0);
		jacket = new Jacket(29999,0.2,1);
		trousers = new Trousers(79999,0.1,1);
		People p_2 = new People(cap,jacket,trousers);
		double re_2 = PeopleTest.cal(cap, jacket, trousers);
		
		cap = new Cap(199,0.1,0);
		jacket = new Jacket(9999,0.2,1);
		trousers = new Trousers(799,0.1,1);
		People p_3 = new People(cap,jacket,trousers);
		double re_3 = PeopleTest.cal(cap, jacket, trousers);
		
		cap = new Cap(2199,0.1,0);
		jacket = new Jacket(49999,0.2,1);
		trousers = new Trousers(6799,0.1,1);
		People p_4 = new People(cap,jacket,trousers);
		double re_4 = PeopleTest.cal(cap, jacket, trousers);
		
		cap = new Cap(199,0.1,0);
		jacket = new Jacket(9999,0.2,1);
		trousers = new Trousers(799,0.1,1);
		People p_5 = new People(cap,jacket,trousers);
		//这里故意写错一个
		double re_5 = PeopleTest.cal(cap, jacket, trousers)+1;
		
		
		
		return Arrays.asList(new Object[][] {
			{p_1,re_1},
			{p_2,re_2},
			{p_3,re_3},
			{p_4,re_4},
			{p_5,re_5},
		});
	}
	
	//使用构造函数将列表中的数据复制到private中
	public PeopleTestParameterized(People param, double result){
		this.param = param;
		this.result = result;
	}
	
	//观察发现，这里的test1也执行了5次。
	@Test
	public void test1() {
		System.out.print("sdf");
	}
	
	//进行多个测试用例测试
	@Test
	public void testGetAllPrice() {
		double re=0; 
		assertEquals(result, param.getAllprice());
	}
}

运行结果
故意写错的那个用例就是[4]

ant报告，就是测试用例10个，但是有一个错误的那个。

小结
在使用参数化测试方法中。

首先要在测试类前一行写入 @RunWith(Parameterized.class) 表明这个类使用的是参数化测试方法。随后定义两个private变量param与result。前者为测试用例输入，后者为测试用例输出。

其次，要确保Collection数据书写正确，参数化测试方法的数据来源即该Collection数据。并且该方法头部使用@Parameters。

第三步，正确书写构造函数，这里的构造函数的功能是将Collection数据列表中数据赋值给两个private变量，param，result。

最后，编写测试代码即可。

单元测试中掌握参数化测试方式是比较重要的，通过以上简单的示例记录本次学习内容。