How to find the deserializer used by jersey

Question

In our jersey project, we are using 2 json providers, Moxy and Jackson. I want to know which provider is being used to deserialize my payload, whether its Moxy or Jackosn. Is there any way to find it?

Answer 1

There are ways to find it, but it unnecessary, as generally, the same one will be used. The way Jersey (2.x) is set up, is that MOXy (jersey-media-moxy) is the default provider. If you have both on the classpath, without any further configuration, MOXy will be used.

There are a couple of ways to disable MOXy. Either explicitly register the JacksonFeature (that comes with jersey-media-json-jackson), or set the property ServerProperties.MOXY_JSON_FEATURE_DISABLE to true

But just for completeness, the couple ways I can think of top of my head to figure out which one is being used

• Trigger an exception and handle it in a mapper. Check the stack trace. (I know not very elegant)
• Write a ContextResolver for the ObjectMapper. If Jackson is being used, the getContext method will be called (just add an s.o.p). See here
• You could retrieve the provider through the injectable Providers interface. See here

There are probably other ways, but like I said, it doesn't really seem necessary. You should already know.