在春季有条件地制作豆子

Question

Right now I'm exposing the service layer of my application using spring remoting's RMI/SOAP/JMS/Hessian/Burlap/HttpInvoker exporters. What I'd like is to allow the user to somehow define which of these remoting mechanisms they'd like enabled (rather than enabling all of them), then only create those exporter beans.

I was hoping that spring's application context xml's had support for putting in conditional blocks around portions of the xml. However, from what I've seen so far there's nothing in the standard spring distribution that allows you to do something like this.

Are there any other ways to achieve what I'm trying to do?

Answer 1

I am going to assume that you are looking to configure your application based on your environment, as in... for production I want to use this beans, in dev these other ...

As Ralph is saying, since Spring 3.1 you have profiles... But the key, is that you understand that you should put your environment based beans in different configuration files... so you could have something like dev-beans.xml, prod-beans.xml... Then in your main spring file, then you just invoke the appropriate one based on the environment that you are using... So profiles are only technique to do so... But you can also use other techniques, like have a system environmental variable, or pass a parameter in your build to decide which beans you want to use

Answer 2

You could realize this by using a Spring @Configuration bean, so you can construct your beans in java code. (see http://static.springsource.org/spring/docs/3.1.x/spring-framework-reference/html/beans.html#beans-java )

@Configuration
public class AppConfig {
  @Bean
  public MyService myService() {
      if ( userSettingIshessian ) {
          return new HessianExporter();
      }else {
          return new BurlapExporter();
      }
  }
}

Of course you need to get the user setting from somewhere, a system parameter would be easy, or config file, or something else.

Answer 3

Spring 3.1 has the concept of Profiles. My you can use them.