SpringJUnit4ClassRunner 应该初始化它的上下文多少次？

Question

The Test annotation tells JUnit that the public void method to which it is attached can be run as a test case. To run the method, JUnit first constructs a fresh instance of the class then invokes the annotated method. Any exceptions thrown by the test will be reported by JUnit as a failure. If no exceptions are thrown, the test is assumed to have succeeded.

这可能意味着，对于每个 @Test 方法，上下文都应该再次初始化。这个答案也证实了这一点：

同时，我在实验中看到了相反的结果：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringJUnit4ClassRunnerDemo._Config.class)
public class SpringJUnit4ClassRunnerDemo {


    public static class Bean1 {
        {
            System.out.println("Bean1 constructor called");
        }
    }

    public static class Bean2 {

        {
            System.out.println("Bean2 constructor called");
        }

        private Bean1 bean1;

        public Bean1 getBean1() {
            return bean1;
        }

        @Autowired
        public void setBean1(Bean1 bean1) {
            this.bean1 = bean1;

            System.out.println("Bean2.bean1 property set");
        }
    }

    @Configuration
    public static class _Config {

        @Bean
        public Bean1 bean1() {
            return new Bean1();
        }

        @Bean
        public Bean2 bean2() {
            return new Bean2();
        }


    }

    @Autowired
    private Bean1 bean1;

    @Autowired
    private Bean2 bean2;


    @Test
    public void testBean1() {

        assertNotNull(bean1);

        System.out.println("testBean1() done");
    }

    @Test
    public void testBean2() {

        assertNotNull(bean2);

        assertSame(bean2.getBean1(), bean1);

        System.out.println("testBean2() done");
    }


}

这段代码输出

Bean1 constructor called
Bean2 constructor called
Bean2.bean1 property set
testBean1() done
testBean2() done

这可能意味着，在第二次测试之前，上下文没有第二次初始化。

什么是实际和正确的行为以及如何控制它？

Answer 1

如果你想在测试方法之间重新加载Spring上下文，你需要使用@DirtiesContext注解：https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/test/annotation/DirtiesContext.html

SpringJUnit4ClassRunner 应该初始化它的上下文多少次？

How many times should SpringJUnit4ClassRunner initialize it's context?

java

junit

spring

unit-testing