You can create filters and easily bind them to the endpoints you need to log, keeping your endpoints lean and focused on the business logic.
Defining a name binding annotation
To bind filters to your REST endpoints, JAX-RS provides the meta-annotation @NameBinding
and it can be used as following:
@NameBinding
@Retention(RUNTIME)
@Target({TYPE, METHOD})
public @interface Logged { }
Logging the HTTP request
The @Logged
annotation will be used to decorate a filter class, which implements ContainerRequestFilter
, allowing you to handle the request:
@Logged
@Provider
public class RequestLoggingFilter implements ContainerRequestFilter {
@Override
public void filter(ContainerRequestContext requestContext) throws IOException {
// Use the ContainerRequestContext to extract information from the HTTP request
// Information such as the URI, headers and HTTP entity are available
}
}
The @Provider
annotation marks an implementation of an extension interface that should be discoverable by JAX-RS runtime during a provider scanning phase.
The ContainerRequestContext
helps you to extract information from the HTTP request.
Here are methods from the ContainerRequestContext
API to get information from the HTTP request that can be useful for your logs:
Logging the HTTP response
For logging the response, consider implementing a ContainerResponseFilter
:
@Logged
@Provider
public class ResponseLoggingFilter implements ContainerResponseFilter {
@Override
public void filter(ContainerRequestContext requestContext,
ContainerResponseContext responseContext) throws IOException {
// Use the ContainerRequestContext to extract information from the HTTP request
// Use the ContainerResponseContext to extract information from the HTTP response
}
}
The ContainerResponseContext
helps you to extract information from the HTTP response.
Here are some methods from the ContainerResponseContext
API to get information from the HTTP response that can be useful for your logs:
Binding the filters to your endpoints
To bind the filter to your endpoints methods or classes, annotate them with the @Logged
annotation defined above. For the methods and/or classes which are annotated, the filters will be executed:
@Path("/")
public class MyEndpoint {
@GET
@Path("{id}")
@Produces("application/json")
public Response myMethod(@PathParam("id") Long id) {
// This method is not annotated with @Logged
// The logging filters won't be executed when invoking this method
...
}
@DELETE
@Logged
@Path("{id}")
@Produces("application/json")
public Response myLoggedMethod(@PathParam("id") Long id) {
// This method is annotated with @Logged
// The request logging filter will be executed before invoking this method
// The response logging filter will be executed before invoking this method
...
}
}
In the example above, the logging filters will be executed only for myLoggedMethod(Long)
because it's annotated with @Logged
.
Additional information
Besides the methods available in ContainerRequestContext
and ContainerResponseFilter
interfaces, you can inject ResourceInfo
in your filters using @Context
:
@Context
ResourceInfo resourceInfo;
It can be used to get the Method
and the Class
which match with the requested URL:
Class<?> resourceClass = resourceInfo.getResourceClass();
Method resourceMethod = resourceInfo.getResourceMethod();
HttpServletRequest
and HttpServletResponse
are also available for injection:
@Context
HttpServletRequest httpServletRequest;
@Context
HttpServletResponse httpServletResponse;
Refer to this answer for the types that can be injected with @Context
.