Jersey 2.6 with Jackson JSON deserialization

Question

My goal is to make web calls and convert returned JSON to POJOs. I'm trying to use Jersey+Jackson for this but am getting exceptions when running. My maven pom file includes the following dependencies - ``` org.glassfish.jersey.core jersey-client 2.6 org.glassfish.jersey.media jersey-media-json-jackson 2.6 ``` The code I use to make fetch some data is as follows - ``` Client client = ClientBuilder.newBuilder() .register(JacksonFeature.class) .build(); ClientResponse response = client.target(url).request(MediaType.APPLICATION_JSON).get(ClientResponse.class); ``` But the following exception is throw - ``` javax.ws.rs.ProcessingException: Error reading entity from input stream. at org.glassfish.jersey.message.internal.InboundMessageContext.readEntity(InboundMessageContext.java:868) at org.glassfish.jersey.messa…

Accepted Answer

What you need is a Response and not a ClientResponse: ``` javax.ws.rs.core.Response jsonResponse = client.target(url).request(MediaType.APPLICATION_JSON).get(); ``` Then you can see what comes in your response (debugging is your friend here). Is it by any chance a map of some type? If it is, you can read it by doing e.g. ``` Map entitiesFromResponse = jsonResponse.readEntity(new GenericType>() {}); ``` If you've put a normal entity in the response you can simply do something like: ``` SomeClassOfYours entityFromResponse = jsonResponse.readEntity(SomeClassOfYours.class); ``` Edit: For this to work you'd also need to define SomeClassOfYours and put the corresponding fields, constructor, getters and setters in there. Edit2: When in doubt you can always read the jsonResponse as a `String.class` and put it in a `String` variable.

Jersey 2.6 with Jackson JSON deserialization

Solution

Problem