How does one intercept a request during the Jersey lifecycle?

Question

I've used Jersey for the better part of a year now and have just stumbled upon a problem to which I can't find the answer: how do you intercept (or hook into) the Jersey request lifecycle?

Ideally, I'd be able to perform some custom filtering/validation/rejection between the time the container accepts the request from the network and the time my handler methods are called. Bonus points if there's an easy way to filter the interceptors by sub-path (e.g. have one interceptor for anything under /, another for anything under /user/, etc.).

Thanks!

Edit: To be a bit clearer, the general idea here is to be able to write some code that will be run for many API calls without having to explicitly call that code from each handler method. This would reduce extra code and eliminate the need to pass request contexts around.

Fillet

What kind of filtering, validation, rejection do you want? For example, you can create your own MessageBodyWriter/Reader to handle validation. Or you can set the @Context in the constructor for custom HTTP header parsing or URI parsing. – Gaona

Most applications of this feature would be related to security. For example, my (non-Jersey) web application will generate one-time-use nonces for certain AJAX calls (all under the same path) to Jersey. The interceptor would be responsible for checking the validity of this nonce. – Fillet

@Gaona can you tell a bit more about the "Or you can set the @ Context in the constructor for custom HTTP header parsing or URI parsing" part please ? – Polydactyl

Answer 1

I've found the answer.

First, create a class that implements ContainerRequestFilter. The interface specifies the following method, in which the filtering takes place. The ContainerRequest object contains information about the current request.

public ContainerRequest filter(ContainerRequest req);

After that, include the following XML in the servlet configuration in web.xml

<init-param>
  <param-name>com.sun.jersey.spi.container.ContainerRequestFilters</param-name>
  <param-value>path.to.filtering.class</param-value>
</init-param>

Sources:

http://jersey.576304.n2.nabble.com/ContainerRequestFilter-and-Resources-td4419975.html http://markmail.org/message/p7yxygz4wpakqno5

Fillet

Thanks for adding your solution - it's useful for the rest of us – Grassgreen

Is there any annotation for this? – Jaine

How to Reject Request with this ? – Greenheart

Answer 2

This thread is a bit old, but I was having a fit of a time intercepting both before and after the request. After a long search on the web, I finally figured this out:

<init-param>
    <param-name>com.sun.jersey.spi.container.ContainerResponseFilters</param-name>
    <param-value>blah.LoggingFilter</param-value>
</init-param>
<init-param>
    <param-name>com.sun.jersey.spi.container.ContainerRequestFilters</param-name>
    <param-value>blah.LoggingFilter</param-value>
</init-param>

and then this class:

public class LoggingFilter extends LoggingFilter implements ContainerRequestFilter {

    private static final ThreadLocal<Long> startTime = new ThreadLocal<Long>();
    public static boolean verboseLogging = false;

    @Override
    public ContainerRequest filter(ContainerRequest arg0) {
        startTime.set(System.currentTimeMillis());
        return arg0;
    }

    @Override
    public ContainerResponse filter(ContainerRequest request, ContainerResponse response) {
        System.out.println(System.currentTimeMillis() - startTime.get().longValue());
        StringBuilder sb = new StringBuilder();
        sb.append("User:").append((request.getUserPrincipal() == null ? "unknown" : request.getUserPrincipal().getName()));
        sb.append(" - Path:").append(request.getRequestUri().getPath());
        //...
    }

This intercepts the request at the beginning and the end so you can put in a timer or whatever.

This works for Jersey 1.17. Not sure about 2.x.

Richman

@Override public ContainerResponse filter(...) is not valid in this type of class. – Scrupulous

Answer 3

For the server part we use a Jersey Specific class to do something like this: ContainerResponseFilter

The signature is:

public ContainerResponse filter(ContainerRequest request, ContainerResponse response)

then you can do calls like:

Object entity  = response.getEntity();
    ... your logic here ...
return response;

Can this be of some help ?..

Caoutchouc

Answer 4

Have you looked at the Jersey ClientFilter class ?

We are currently using this to intercept and perform API versioing etc.. There is built in logging filters - so you can look at the code for them to get an idea of what to write.

The signature is:

public ClientResponse handle(final ClientRequest cr) throws ClientHandlerException...

So you can start by doing stuff like:

....
cr.getHeaders()
....
return getNext().handle(cr);

Caoutchouc

It looks like this works on the client-side only. Do you know if there's a similar filtering mechanism for the server? – Fillet