Response Filtering

JSR-359 defines annotations for filtering responses. The defined annotations are @ProvisionalResponse, @SuccessResponse, @RedirectResponse, and @ErrorResponse. These annotations use the SIP meta-annotation @SipResponseRange to specify the response code range.

Table 3-1 lists the Response annotations and their associated response ranges.

Table 3-1 Response Range Annotations

Annotation	Response Range Begin	Response Range End
@ProvisionalResponse	101	199
@SuccessResponse	200	299
@RedirectResponse	300	399
@ErrorResponse	400	699

Example 3-2 shows the usage of a response range annotation.

Example 3-2 Response Range Annotation

@SuccessResponse
public void handleSuccessResponse(SipServletResponse response) {
  //...
}

To further filter responses, a POJO may combine both a method specific annotation and a Response Filter annotation. Example 3-3 shows how to handle success responses for INVITE messages.

Example 3-3 Combining Annotations

@Invite @SuccessResponse
public void handleInviteSuccessResponse(SipServletResponse response) {
  //...
}

It is also possible to specify multiple response filter annotations to a Java method, allowing application developers to handle multiple ranges using the same annotation. Example 3-4 shows how to handle multiple response ranges.

Example 3-4 Multiple Response Range Annotations

@Invite @ProvisionalResponse @SuccessResponse
public void handleInviteSuccessResponse(SipServletResponse response) {
  //...
}

@BranchResponse Annotation

An application can use the built-in SipPredicate, @BranchResponse, to associate an intermediate final response that arrives on a ProxyBranch with a Java method in a SIP Servlet POJO.

Example 3-5 shows the @BranchResponse definition.

Example 3-5 @BranchResponse Definition

@Retention(RUNTIME)
@Target({METHOD})
@SipPredicate(BranchResponse.Predicate.class)
public @interface BranchResponse {
  class Predicate implements
  javax.servlet.sip.Predicate<SipServletResponse> {
    @Override
    public boolean apply(final SipServletResponse response) {
      return response.isBranchResponse();
    }
  }