Validate JAX-RS query parameters

 

It’s easy to validate parameters in JAX-RS using filters – ContainerRequestFilter to be specific. There are other options at your disposal e.g. using (CDI or EJB) interceptors, or injecting (HttpServletRequest using @Context)

Scenario – Validate query parameter passed in by the caller

Steps

  • Implement filter
  • Extracts query parameter from ContainerRequestContext
  • Performs the validation – aborts the request with an appropriate response status (and the error message)

@Provider
@QueryParamValidator
public class JAXRSReqFilter implements ContainerRequestFilter{
@Override
public void filter(ContainerRequestContext requestContext) throws IOException {
MultivaluedMap<String, String> queryParameters = requestContext.getUriInfo().getQueryParameters();
String queryParam = queryParameters.keySet().stream().findFirst().get();
System.out.println("Query param – "+ queryParam);
if(!queryParam.equals("p")){
requestContext.abortWith(Response
.status(Response.Status.BAD_REQUEST)
.entity("Invalid Query Param "+ queryParam)
.build());
}
}
}

Enforce filter

  • Use @NameBinding to decorate custom annotation
  • Use the custom annotation on the JAX-RS method
@NameBinding
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
public @interface QueryParamValidator {
}

@Path("test")
public class TestResource {
@GET
@QueryParamValidator
public String test(@QueryParam("p") String p){
return "Param "+ p + " on " + new Date();
}
}

Further reading

Cheers!

 

 

About Abhishek

Loves Go, NoSQL DBs and messaging systems
This entry was posted in Java, Java EE and tagged , . Bookmark the permalink.

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