Intellij IDEA 2018.2 使用 JUnit4

阳光穿透心脏的1/2处 2023-10-18 18:15 47阅读 0赞

#### 导入 jar 包:在这个[https://mvnrepository.com/artifact/junit/junit][https_mvnrepository.com_artifact_junit_junit]下载哦! ####

![20190508135138265.png][]

### 情景代码 ###

public class Calculator {
    
        public int add(int a, int b) {
            return a + b ;
        }
    
        public int sub(int a, int b) {
            return a - b ;
        }
    
        public int mul(int a, int b) {
            return a * b ;
        }
    
        public int div(int a, int b) {
            if(b == 0) {
                throw new ArithmeticException("除数不能为零") ;
            }
    
            return a / b ;
        }
    
    }

### 使用右键相应的类，Go To --> Test，弹出如下框 ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70][]

打开对话框

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 1][]

点击OK后，IDEA 将自动 生成测试代码方法，具体内容是需要填写的哦！

public class CalculatorTest2 {
    
    
        /**
         * 类加载开始
         */
        @BeforeClass
        public static void beforeClass() {
            System.out.println("Before Class");
        }
    
        /**
         * 类加载结束
         */
        @AfterClass
        public static void afterClass() {
            System.out.println("After Class");
        }
    
    
        /**
         * 开始
         * @throws Exception
         */
        @Before
        public void setUp() throws Exception {
            System.out.println("setUp");
        }
        /**
         * 结束
         * @throws Exception
         */
        @After
        public void tearDown() throws Exception {
            System.out.println("tearDown");
        }
    
        @Test
        public void add() {
            System.out.println("add");
            int a = 20 ;
            int b = 10 ;
            Calculator cal = new Calculator() ;
            int result = cal.add(20, 10) ;
            Assert.assertEquals(a + b, result) ;
        }
    
        @Test
        public void sub() {
            System.out.println("sub");
            int a = 20 ;
            int b = 10 ;
            Calculator cal = new Calculator() ;
            int result = cal.sub(20, 10) ;
            //断言
            Assert.assertEquals(a - b, result) ;
    
        }
    
        @Test
        public void mul() {
            System.out.println("mul");
            int a = 20 ;
            int b = 10 ;
            Calculator cal = new Calculator() ;
            int result = cal.mul(20, 10) ;
    
            Assert.assertEquals(a * b, result) ;
        }
    
        @Test
        public void div() {
            System.out.println("div");
            int a = 20 ;
            int b = 10 ;
            Calculator cal = new Calculator() ;
            int result = cal.div(20, 0) ;
    
            Assert.assertEquals(a / b, result) ;
        }
    }

效果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 2][]

![20190508135722152.png][]

如果是错误的，那么就会发生异常的哦！

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 3][]

[https_mvnrepository.com_artifact_junit_junit]: https://mvnrepository.com/artifact/junit/junit
[20190508135138265.png]: https://img-blog.csdnimg.cn/20190508135138265.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20190508135355746.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20190508135458889.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20190508135710212.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70
[20190508135722152.png]: https://img-blog.csdnimg.cn/20190508135722152.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20190508135734676.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hseDIwMDgwODA4,size_16,color_FFFFFF,t_70