Upgrading from Jersey 1.* to Jersey 2.5

Question

I have decided to move to `Jersey 2.5` and I am facing certain issues in `Java Beans` conversion to `JSON`. I have a `User` Bean and from one service I am trying to return a list of `users`. My service code which fetches the list of users: ``` @GET @Path("getAllUsers") @Produces(MediaType.APPLICATION_JSON) public List getAllUsers() { //Fetching users list here return users; } ``` I get following exception of server console: ``` [org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class java.util.ArrayList, genericType=java.util.List.] with root cause org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class java.util.ArrayList, genericType=java.util.List. at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(Writer…

Accepted Answer

Since you're using Jackson 1.9.x to (un)marshall JSON, make sure you have `jersey-media-json-jackson` module in your dependency list and that you're registering JacksonFeature in your application, i.e.:

```
public class MyResourceConfig extends ResourceConfig {

public MyResourceConfig() {
        // ... other registrations ...

register(JacksonFeature.class);
    }
}
```

To see more ways how to register providers in Jersey 2 refer to this article.

Upgrading from Jersey 1.* to Jersey 2.5

Solution

Problem