Proxy `@RabbitListener` and Generics

如果你的服务打算被代理（例如，在 @Transactional 的情况下），当接口具有泛型参数时，你应该记住一些注意事项。考虑以下示例：

If your service is intended to be proxied (for example, in the case of @Transactional), you should keep in mind some considerations when the interface has generic parameters. Consider the following example:

interface TxService<P> {

   String handle(P payload, String header);

}

static class TxServiceImpl implements TxService<Foo> {

    @Override
    @RabbitListener(...)
    public String handle(Thing thing, String rk) {
         ...
    }

}

使用通用接口和特定实现，你被迫切换到 CGLIB 目标类代理，因为接口`handle`方法的实际实现是桥接方法。在事务管理的情况下，通过使用注解选项`@EnableTransactionManagement(proxyTargetClass = true)`来配置 CGLIB 的使用。在此情况下，所有注解必须在实现类的目标方法上声明，如下例所示：

With a generic interface and a particular implementation, you are forced to switch to the CGLIB target class proxy because the actual implementation of the interface handle method is a bridge method. In the case of transaction management, the use of CGLIB is configured by using an annotation option: @EnableTransactionManagement(proxyTargetClass = true). And in this case, all annotations have to be declared on the target method in the implementation, as the following example shows:

static class TxServiceImpl implements TxService<Foo> {

    @Override
    @Transactional
    @RabbitListener(...)
    public String handle(@Payload Foo foo, @Header("amqp_receivedRoutingKey") String rk) {
        ...
    }

}

Proxy @RabbitListener and Generics

Proxy `@RabbitListener` and Generics