Junit单元测试学习笔记（一）

l 使用方法

下载junit

https://github.com/junit-team/junit/wiki/Download-and-Install

使用junit jar包

l 一个简单的test

1.创建类

public class calc {
 
    /**
     * @param args
     */
    public static int add(int first_num,int second_num)   //add method
       {
           return  first_num+second_num;
       }
    public static int minus(int first_num,int second_num)   //minus method 
        {
            return  first_num-second_num;
        }
    public static int multiplication(int first_num,int second_num) //multiplication method
        {
            return  first_num*second_num;
        }
    public static int division(int first_num,int second_num)
        {
            return  first_num/second_num;  
            // division will throw ArithmeticException when the second_num=0
        }
    public static Boolean endless_loop()   //endless loop
    {
        for(;;);                             //junit time out 
          
    }
      
}

2.创建test case

TestCase类给我们提供了setUp方法和tearDown方法，setUp方法的内容在测试你编写的TestCase子类的每个testXxxx方法之前都会运行，而tearDown方法的内容在每个testXxxx方法结束以后都会执行。

我们创建setUp方法：

import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Rule;
import org.junit.Test;
  
 
public class calcTest {
 
    @Test
    public void testAdd() {
        assertEquals(5, calc.add(2,3)); 
         
    }
 
    @Test
    public void testMunius() {
        assertEquals(5, calc.minus(2,3));
    }
    @Ignore("testMultiplication() Not yet implemented") //ignore this case
    @Test
    public void testMultiplication() {
        assertEquals(6, calc.multiplication(2,3));
    }
     
  
    @Test(expected=ArithmeticException.class)  // catch ArithmeticException exception
    public void testDivision () throws Exception {
        assertEquals(-1, calc.division(2,0));
     }
 
    @Test(timeout = 10000)   //defined time out =10 seconds
    public void testEndless_loop() {
        assertTrue("true",calc.endless_loop()); // can’t return within 10 seconds
    }
 
}