JAX-RS, Spring & ServletConfig: How to access Servlet Config in Configurator

Question

I have troubles getting a javax.servlet.ServletConfig into a class annotated with org.springframework.context.annotation.Configuration.

My team decided that we should use spring for dependency injection and I'm trying to use it to migrate one of our simple Rest services.

My constraints are:

• JAX-RS: We have several REST Services implemented JAX-RS and we don't really want to change that.
• Not bound to a specific implementation of JAX-RS (Jersey & RESTEasy work fine for us and we can change from one to the other without changing underlying code)
• Import as few dependencies as possible from spring: at the moment I import only org.springframework:spring-context from the spring project.
• No API breakage: Deprecated is fine but the service should keep working during the transition, using our old way of doing things.
• A string parameter is defined in the service's web.xml. I need to get it, instantiate a Bean with it and inject the resulting bean at several place in the code.
• I don't want to mess with Spring Boot/MVC/... as the service already works and I just want the Dependency Injection part.

What I already have:

The code use javax.ws.rs.core.Application, with a class that look like that:

public class MyApplication extends Application {

  @Context
  private ServletConfig cfg;

  public DSApplication() {
  }

  @Override
  public Set<Class<?>> getClasses() {
      return new HashSet<>();
  }

  @Override
  public Set<Object> getSingletons() {
    Set<Object> set = new HashSet<>();
    String injectionStr = cfg.getInitParameter("injection");
    boolean injection = false;
    if (null != injectionStr && !injectionStr.isEmpty()) {
        injection = Boolean.valueOf(injectionStr);
    }

    if (injection) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
                DSServiceProducer.class,
                CContextBeanProvider.class
        );
        IDSService service = context.getBean(IDSService.class);
        set.add(service);
    } else {
        set.add(new DSService()); //Old way
    }
    return set;
  }
}

I need the servlet config in CContextBeanProvider, which look like:

@Configuration
public class CContextBeanProvider {

  private ServletConfig cfg; // How to get this here ?

  @Bean
  public CContextBean cContextBean() {
    String bean = cfg.getInitParameter("cpuContext");
    return new CContextBean(bean);
  }
}

CContextBean is a setting bean initialized from a string found in the web.xml of the service.

• Is it possible ?
• Do you have any idea how ?
• Would it be easier with CDI, knowing that we run on base Tomcat ? (I've already find this if I need to use tomcat with CDI)

Answer 1

Could you please try to add all jersey CDI related jars to your applications ?