使用套件时的 JUnit 4 @BeforeClass 和 @AfterClass

使用下面的这种方法时，通过使用 Suites 设置 jUnit。当每个 Testclass 中的所有 @BeforeClass 将在任何测试开始执行之前执行时，我们就会遇到问题。 （对于每个n个TestClass文件，@BeforeClass运行，然后在它们执行后，它开始执行第一个MyTest.class文件@Test）

这将导致我们分配大量的资源和内存。 我的想法是，这一定是错误的，每个 @BeforeClass 不应该只在执行实际测试类之前运行，而不是在 Suite 启动时运行吗？

@RunWith(Suite.class)
@Suite.SuiteClasses({ MyTests.class, Mytests2.class, n1, n2, n })
public class AllTests {
    // empty
}


public class MyTests {  // no extends here
    @BeforeClass
    public static void setUpOnce() throws InterruptedException {
        ...
    @Test
        ...

public class MyTests2 {  // no extends here
    @BeforeClass
    public static void setUpOnce() throws InterruptedException {
        ...
    @Test
        ...

Write a @BeforeClass方法中的AllTests套件启动时将执行的类。

public class MyTests1 { 
    @BeforeClass
    public static void beforeClass() {
        System.out.println("MyTests1.beforeClass");
    }

    @Before
    public void before() {
        System.out.println("MyTests1.before");
    }

    @AfterClass
    public static void afterClass() {
        System.out.println("MyTests1.AfterClass");
    }

    @After
    public void after() {
        System.out.println("MyTests1.after");
    }

    @Test
    public void test1() {
        System.out.println("MyTests1.test1");
    }

    @Test
    public void test2() {
        System.out.println("MyTests1.test2");
    }
}



public class MyTests2 { 
    @BeforeClass
    public static void beforeClass() {
        System.out.println("MyTests2.beforeClass");
    }

    @Before
    public void before() {
        System.out.println("MyTests2.before");
    }

    @AfterClass
    public static void afterClass() {
        System.out.println("MyTests2.AfterClass");
    }

    @After
    public void after() {
        System.out.println("MyTests2.after");
    }

    @Test
    public void test1() {
        System.out.println("MyTests2.test1");
    }

    @Test
    public void test2() {
        System.out.println("MyTests2.test2");
    }
}




@RunWith(Suite.class)
@Suite.SuiteClasses( { MyTests1.class, MyTests2.class })
public class AllTests {

    @BeforeClass
    public static void beforeClass() {
        System.out.println("AllTests.beforeClass");
    }

    @Before
    public void before() {
        System.out.println("AllTests.before");
    }

    @AfterClass
    public static void afterClass() {
        System.out.println("AllTests.AfterClass");
    }

    @After
    public void after() {
        System.out.println("AllTests.after");
    }

    @Test
    public void test1() {
        System.out.println("AllTests.test1");
    }

    @Test
    public void test2() {
        System.out.println("AllTests.test2");
    }
    
}

Output:

AllTests.beforeClass
MyTests1.beforeClass
MyTests1.before
MyTests1.test1
MyTests1.after
MyTests1.before
MyTests1.test2
MyTests1.after
MyTests1.AfterClass
MyTests2.beforeClass
MyTests2.before
MyTests2.test1
MyTests2.after
MyTests2.before
MyTests2.test2
MyTests2.after
MyTests2.AfterClass
AllTests.AfterClass