Spring中Bean初始化和销毁方法执行的优先级

Spring有三对初始化和销毁方法

1. 通过@Bean注解指定initMethod和destroyMethod
2. 实现InitializingBean和DisposableBean接口
3. 使用@PostContruct和@PreDestroy

那么问题来了，这三个执行的优先级是什么呢？

定义一个Car类

public class Car implements InitializingBean, DisposableBean {

    public Car() {
        System.out.println("car constructor");
    }

    @PostConstruct
    public void postConstruct(){
        System.out.println("postConstruct");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("InitializingBean afterPropertiesSet");
    }

    public void initMethod(){
        System.out.println("initMethod");
    }

    @PreDestroy
    public void preDestroy(){
        System.out.println("preDestroy");
    }

    @Override
    public void destroy(){
        System.out.println("DisposableBean destroy");
    }

    public void destroyMethod(){
        System.out.println("destroyMethod");
    }
}

定义配置类，并注入

@Configuration
public class MyConfigOfLifeCycle {

    @Bean(initMethod = "initMethod",destroyMethod = "destroyMethod")
    public Car car(){
        return new Car();
    }
}

测试

@Test
public void test04(){
    AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyConfigOfLifeCycle.class);
    System.out.println("容器创建完成");
    Object car = context.getBean("car");
    context.close();
}

执行结果

car constructor
postConstruct
InitializingBean afterPropertiesSet
initMethod
容器创建完成
preDestroy
DisposableBean destroy
destroyMethod

结论

优先级：@PostConstruct>InitializingBean>通过@Bean指定