But the question is not just whether Jersey itself is thread-safe, but
whether this code that calls it would be. And I think the answer to that
latter is "no" ... If the instance that has the jerseyTarget variable can
be used by multiple threads, it is possible that from any one thread's
perspective, the value of the variable could change in between two uses of
that variable in that thread - which probably is not what the thread
expected would happen?
I would think either that instance that has the jerseyTarget is already
itself MT-safe, or you could do things like making jerseyTarget use
ThreadLocal storage, so that different threads would each get their own
instance...
Moises
On Thu, Dec 11, 2014 at 11:38 AM, cowwoc <cowwoc_at_bbs.darktech.org> wrote:
> Hi Damian,
>
> I don't see why either case is a threading problem.
>
> If Client and WebTarget are thread-safe (JAX-RS doesn't indicate either
> way, but unofficially they are supposed to be) then either approach would
> work fine.
>
> Gili
>
>
> On 11/12/2014 11:32 AM, Sobieralski, Damian Michael wrote:
>
>> I have a question about thread safety here. This is a much lower level
>> discussion than what have been reading here and touches on Java threading
>> 101.
>>
>> In a backend service object (we have something like this - this object
>> sits in a servlet container):
>>
>> protected Client jerseyClient = null;
>> protected WebTarget jerseyTarget = null;
>>
>> These are class variables. This is normally a warning flag for threading
>> issues
>>
>> Then we have code like this:
>>
>> protected void readyConnection() throws Exception {
>> jerseyClient = ClientBuilder.newBuilder().
>> register(JacksonFeature.class).build();
>>
>> jerseyTarget = jerseyClient.target(baseUrl).
>> path("api").path("v1");
>> }
>>
>> and methods that use jerseyTarget. Is this a bad idea thread wise? It
>> seems like jersey client is fine being a class variable. But that
>> jerseyTarget in this ready method instead of setting the class variable
>> jerseyTarget should return its own jerseyTarget.
>>
>> So, is it better to do this?
>>
>> protected WebTarget readyConnection() throws Exception {
>> jerseyClient = ClientBuilder.newBuilder().
>> register(JacksonFeature.class).build();
>>
>> return jerseyClient.target(baseUrl).path("api").path("v1");
>> }
>>
>> - Damian
>>
>>
>