kafka仿feign进行rpc调用

最新推荐文章于 2024-06-13 15:17:25 发布

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最新推荐文章于 2024-06-13 15:17:25 发布 · 2.1k 阅读

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#kafka rpc feign

本文介绍了一种使用Kafka替代Feign进行RPC调用的方法。通过定义`KafkaRpcScan`和`KafkaRpcClient`注解，扫描并注册带有指定注解的接口，并使用动态代理来实现接口方法的调用。`KafkaRpcBean`作为FactoryBean处理请求和响应，`ReplyingKafkaTemplate`用于发送和接收Kafka消息。接收端通过`@KafkaListener`监听主题，解析请求并调用相应Controller的方法，返回结果。示例展示了如何创建`UserRpcService`接口，以及其实现类`KafkaUserController`。

spring配置类

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Import(KafkaRpcScanRegistrar.class)
public @interface KafkaRpcScan {
String[] value() default {};
Class<? extends KafkaRpcBean> factoryBean() default KafkaRpcBean.class;
}

注解类

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(MapperScannerRegistrar.class)
public @interface KafkaRpcClient {

   String topic();
   String replyTopic();
   String value();//beanName 对方调用的Controller对应的类上RequestMap
}

对接口解析加入springbean

public class KafkaRpcScanRegistrar implements ImportBeanDefinitionRegistrar, ResourceLoaderAware,ApplicationContextAware {
private ResourceLoader resourceLoader;

   @Override
   public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
       AnnotationAttributes annoAttrs = AnnotationAttributes
               .fromMap(importingClassMetadata.getAnnotationAttributes(KafkaRpcScan.class.getName()));
       String[] packs = annoAttrs.getStringArray("value");
       Class<? extends Object> factoryBean = annoAttrs.getClass("factoryBean");

AnnotatedTypeScanner beanScanner = new AnnotatedTypeScanner(KafkaRpcClient.class);

Set<Class<?>> beanDefinitions = beanScanner.findTypes(packs);
for (Class<?> bd : beanDefinitions) {

           BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(bd);
           GenericBeanDefinition definition = (GenericBeanDefinition) builder.getRawBeanDefinition();
           definition.getPropertyValues().add("rpcInterface", definition.getBeanClassName());
           definition.getPropertyValues().add("context", context);

           definition.setBeanClass(KafkaRpcBean.class);
           definition.setAutowireMode(GenericBeanDefinition.AUTOWIRE_BY_TYPE);
           String beanName=bd.getSimpleName().substring(0, 1).toLowerCase()+bd.getSimpleName().substring(1);
           registry.registerBeanDefinition(beanName, definition);
       }

}

   @Override
   public void setResourceLoader(ResourceLoader resourceLoader) {
       this.resourceLoader = resourceLoader;
   }
   private ApplicationContext context;
   @Override
   public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
       this.context=applicationContext;

   }

}

接口方法的动态代理封装，接口方法的具体实现
public class KafkaRpcBean<T> implements FactoryBean<T> {
Class<T