编写springboot插件，完成对IOC容器中的Bean的属性修改

Question

编写的插件需要满足第一个要求，请给出测试代码的截图和运行效果截图。

Answer 1

1.代码示例

@Component
public class TestBean implements SmartInitializingSingleton {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public void afterSingletonsInstantiated() {
        System.out.println(this);
        System.out.println("单例Bean实预例化完成之后调用接口");
        this.setName("单例Bean实预例化完成之后调用接口");
    }

    @Override
    public String toString() {
        return "TestBean{" +
                "name='" + name + '\'' +
                '}';
    }
}

@Component
public class TestBeanPostProcessor implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        // 在任何 bean 初始化回调
        //（如 InitializingBean 的 afterPropertiesSet 或自定义 init 方法）之前将此 BeanPostProcessor 应用于给定的新 bean 实例。
        // bean 将已填充属性值。返回的 bean 实例可能是原始的包装器
        if(bean instanceof TestBean){
            System.out.println("bean初始化前回调：" + bean);
            TestBean bean1 = (TestBean) bean;
            bean1.setName("bean初始化前回调");
            return BeanPostProcessor.super.postProcessBeforeInitialization(bean1, beanName);
        }
        return BeanPostProcessor.super.postProcessBeforeInitialization(bean, beanName);
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        // 在任何 bean 初始化回调（如 InitializingBean 的 afterPropertiesSet 或自定义 init 方法）之后，
        // 将此 BeanPostProcessor 应用于给定的新 bean 实例。 bean 将已填充属性值
        if(bean instanceof TestBean){
            System.out.println("bean初始化后回调：" + bean);
            TestBean bean1 = (TestBean) bean;
            bean1.setName("bean初始化后回调");
            return BeanPostProcessor.super.postProcessBeforeInitialization(bean1, beanName);
        }

        return BeanPostProcessor.super.postProcessAfterInitialization(bean, beanName);
    }
}

@SpringBootTest
class SpringbootTestApplicationTests {

    @Autowired
    private TestBean testBean;

    @Test
    void testBeanPostProcessorAndSmartInitializingSingleton() {
        System.out.println(testBean);
    }

}

2.BeanPostProcessor有两个方法，一个在Bean初始化前回调，一个初始化后回调，但都在SmartInitializingSingleton之前执行