Error parsing JSON param in java REST

Question

I have recently upgraded my REST API to use jersey 2.x and now I am unable to retrieve JSON body params the way I used to, the methods simply do not get called anymore. My g

Answer 1

You need a JSON provider

At time of writing, Jersey 2.x integrates with the following modules to provide JSON support:

• MOXy
• Java API for JSON Processing (JSON-P)
• Jackson
• Jettison

Using Jackson

See below the steps required to use Jackson as a JSON provider for Jersey 2.x:

Adding Jackson module dependencies

To use Jackson 2.x as your JSON provider you need to add jersey-media-json-jackson module to your pom.xml file:

    org.glassfish.jersey.media
    jersey-media-json-jackson
    2.25.1

To use Jackson 1.x it'll look like:

    org.glassfish.jersey.media
    jersey-media-json-jackson1
    2.25.1

Registering Jackson module

Besides adding the dependency mentioned above, you need to register JacksonFeature (or Jackson1Feature for Jackson 1.x) in your Application / ResourceConfig subclass:

@ApplicationPath("/api")
public class MyApplication extends Application {

    @Override
    public Set> getClasses() {
        Set> classes = new HashSet>();
        classes.add(JacksonFeature.class);
        return classes;
    }
}

@ApplicationPath("/api")
public class MyApplication extends ResourceConfig {

    public MyApplication() {
        register(JacksonFeature.class);
    }
}

If you don't have an Application / ResourceConfig subclass, you can register the JacksonFeature in your web.xml deployment descriptor. The specific resource, provider and feature fully-qualified class names can be provided in a comma-separated value of jersey.config.server.provider.classnames initialization parameter.

    jersey.config.server.provider.classnames
    org.glassfish.jersey.jackson.JacksonFeature

The MessageBodyWriter provided by Jackson is JacksonJsonProvider.

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For more details, check the Jersey documentation about support for common media type representations.