ConcurrentModificationException when using SwaggerSpecFilter

[srl295]

When using a SwaggerSpecFilter, GET …/swagger.json fails when accessed by as few as 3 clients.

Partial stack trace (1.5.7):

[err] java.util.ConcurrentModificationException
[err]   at java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:711)
[err]   at java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:734)
[err]   at io.swagger.core.filter.SpecFilter.filterDefinitions(SpecFilter.java:200)
[err]   at io.swagger.core.filter.SpecFilter.filter(SpecFilter.java:86)
[err]   at io.swagger.jaxrs.listing.ApiListingResource.process(ApiListingResource.java:121)
[err]   at io.swagger.jaxrs.listing.ApiListingResource.getListingJson(ApiListingResource.java:154)
[err]   at io.swagger.jaxrs.listing.ApiListingResource.getListing(ApiListingResource.java:141)
[err]   at sun.reflect.GeneratedMethodAccessor168.invoke(Unknown Source)
[err]   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[err]   at java.lang.reflect.Method.invoke(Method.java:498)
[err]   at com.ibm.ws.jaxrs20.server.LibertyJaxRsServerFactoryBean.performInvocation(LibertyJaxRsServerFactoryBean.java:607)
[err]   at [internal classes]
[err]   at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
[err]   at com.ibm.websphere.jaxrs.server.IBMRestServlet.service(IBMRestServlet.java:99)
…

Code to reproduce:

        FilterFactory.setFilter(new SwaggerSpecFilter() {
            public boolean isPropertyAllowed(Model model, Property property, String propertyName,
                    Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
                return true;
            }
            public boolean isParamAllowed(Parameter parameter, Operation operation, ApiDescription api,
                    Map<String, List<String>> params, Map<String, String> cookies, Map<String, List<String>> headers) {
                return true;
            }

            public boolean isOperationAllowed(Operation operation, ApiDescription api, Map<String, List<String>> params,
                    Map<String, String> cookies, Map<String, List<String>> headers) {
                return true;
            }
        });

[srl295]

We're not trying to modify the spec on every request. We're just trying to switch off some operations based on static (configuration) parameters. Would it be possible to have some kind of spec filter that's just called one time and then cached? It wouldn't have headers, cookies, etc.

[fehguy]

It's so fast to mutate on each request, that's the recommended way to go. The other way you can hide things is using the hidden=true property which is available in most annotations. Those will cause things to be skipped by the processor. You have more control with the spec filter.

[srl295]

@fehguy right, but we need to hide based on the configuration, not just the annotations. Is there any way to get one-time configuration and caching?

[fehguy]

no, but you do realize that the Spec Filter is going to run in milliseconds, right? That's the design to use, or you can extend the ApiListingResource and cache it yourself.

[webron]

Just pushed 1.5.10-SNAPSHOT with the change, feel free to take it for a spin.

[6vegeta]

I am using the play framework and I had some troubles with injectors and concurrentModificationException. The SBT libraries below helped me to resolve it.
"io.swagger" %% "swagger-play2" % "1.7.1",
"io.swagger" % "swagger-core" % "1.6.10",