通过获取已创建的RestTemboard来拦截RestTemboard

Question

我有逻辑来拦截RestTemboard，我正在添加/注册该RestTemboard在配置文件中（SecurityConfiguration.java），但我想通过获取已注册的RestTemboard对象从另一个配置文件中添加该拦截器：

public class TranslogRestTemplateCondition implements Condition {

    @Override
    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
        boolean isRestTemplate = false;
        try {
            if (context.getBeanFactory() != null) {
                isRestTemplate = (context.getBeanFactory().getBean(RestTemplate.class) != null);
            }
        } catch (BeansException e) {
            return false;
        }
        return isRestTemplate;
    }
}

配置类：

@Configuration
public class RestTemplateConfig {

    private final MyInterceptor myInterceptor;

    @Value("${com.pqr.you.rest.enabled:true}")
    private boolean transEnabled;

    @Autowired
    public RestTemplateConfig(MyInterceptor myInterceptor) {
        this.myInterceptor = myInterceptor;
    }

    @Autowired
    private ApplicationContext appContext;

    // The logic added below is not working for me
    @Bean
    @Conditional(TranslogRestTemplateCondition.class)
    public RestTemplate addInterceptor(ApplicationContext appContext) {
        RestTemplate restTemplate = appContext.getBean(RestTemplate.class);
        if (transEnabled) {
            List<ClientHttpRequestInterceptor> interceptors = restTemplate.getInterceptors();
            interceptors.add(myInterceptor);
            restTemplate.setInterceptors(interceptors);
        }
        return restTemplate;
    }
}

RestTemboard的实际逻辑，它将返回所需的拦截器和一些其他值（在返回此restTemboard时，我的拦截器也需要在此处添加，而不会覆盖现有值）或通过获取下面的restTempalte对象并将MyInterceptor添加到restTemboard。

@Configuration
public class SecurityConfiguration {

    @Bean
    public AbcInterceptor abcRequestInterceptor(XyzService xyzService) {
        return new AbcInterceptor("abc-app", null, xyzService);
    }

    // I dont want to create bean here 
    /*@Bean
    public MyInterceptor myInterceptor() {
        return new MyInterceptor();
    }*/ 

    @Bean
    public RestTemplate restTemplate(AbcRequestInterceptor abcRequestInterceptor) {
        RestTemplate restTemplate = new RestTemplate();
        List<ClientHttpRequestInterceptor> interceptors = new ArrayList<>();
        interceptors.add(abcRequestInterceptor);
        //interceptors.add(myInterceptor); // I dont want to add this interceptor here
        restTemplate.setInterceptors(interceptors);
        return restTemplate;
    }
}

Answer 1

我认为在这种情况下您需要的是一个BeanPostProcess，而不是条件类。如果bean存在，它将允许您修改它。您可以像下面这样创建一个，而不是RestTemplateConfiguration类和条件：

@Configuration
public class RestTemplatePostProcessor implements BeanPostProcessor {

    @Value("${com.pqr.you.rest.enabled:true}")
    private boolean transEnabled;

    @Bean
    MyInterceptor myInterceptor() {
        return new MyInterceptor();
    }

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {

        if (bean instanceof RestTemplate) { // or you can check by beanName if you like
            final RestTemplate restTemplate = (RestTemplate) bean;

            if (transEnabled) {
                List<ClientHttpRequestInterceptor> interceptors = restTemplate.getInterceptors();
                interceptors.add(myInterceptor());
                restTemplate.setInterceptors(interceptors);
            }
            return restTemplate;
        }
        return bean;
    }
}

请注意，在您的代码中，您正在尝试创建另一个RestTemboard实例（名为“addInterceptor”），这似乎是不需要的。