Embedded Jetty: Missing MessageBodyWriter for application/json

Question

First thing: Yes. I did see the 20+ other questions here on stackoverflow, but none of the answers worked out for me.

Runing the unit test below I get:

Could not find MessageBodyWriter for response object of type: jetty.test.JettyTest$Health of media type: application/json

I know I need some sort of JSON mapping provider, however, I have not been able to find any that worked for me. Maybe I also need to exclude something?

Any help is appreciated.

Test class:

package jetty.test;

import static io.restassured.RestAssured.given;
import io.restassured.builder.RequestSpecBuilder;
import io.restassured.filter.log.RequestLoggingFilter;
import io.restassured.filter.log.ResponseLoggingFilter;
import io.restassured.http.ContentType;
import io.restassured.specification.RequestSpecification;
import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Application;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import org.eclipse.jetty.server.Server;
import org.junit.jupiter.api.Test;

import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;
import org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher;


public class JettyTest {           

    @XmlRootElement    
    public static class Health {
        
        public Health () {}

        @XmlElement(name = "status")
        private String status;

        public String getStatus() {
            return status;
        }

        public Health setStatus(String status) {
            this.status = status;
            return this;
        }
    }    
    
    @Path("/health")
    public static class HealthResource {
        
        public HealthResource() {}
        
        @GET
        @Path("/get")
        @Produces(MediaType.APPLICATION_JSON)
        public Response getHealth() {
            return Response.ok().entity(new Health()).build();
        }
    }

    public static class TestApplication extends Application {
        
        public TestApplication () {}
        
        @Override
        public Set<Class<?>> getClasses() {
            HashSet<Class<?>> set = new HashSet<>();
            set.add(HealthResource.class);
            return set;
        }
    }  
    
    @Test
    public void hello() throws Exception {
        
        Server server = new Server(8082);

        ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
        context.setContextPath("/");
        server.setHandler(context);

        final ServletHolder servletHolder = new ServletHolder(new HttpServletDispatcher());
        servletHolder.setInitParameter("resteasy.servlet.mapping.prefix", "/");        
        servletHolder.setInitParameter("javax.ws.rs.Application", TestApplication.class.getName());

        context.addServlet(servletHolder, "/");

        server.start();

        RequestSpecification spec = new RequestSpecBuilder()                
                .setBaseUri("http://localhost:8082")
                .setAccept(ContentType.JSON)
                .addFilter(new ResponseLoggingFilter())
                .addFilter(new RequestLoggingFilter())
                .build();

        given().spec(spec).when().get("/health/get").then().statusCode(200);
    }
}

This is my pom:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.test</groupId>
    <artifactId>JettyTestProject</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.0</version>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.6.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>io.rest-assured</groupId>
            <artifactId>rest-assured</artifactId>
            <version>3.0.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.6.0</version>
            <scope>test</scope>
        </dependency>
        
        
        <dependency>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-server</artifactId>
            <version>9.4.43.v20210629</version>
        </dependency>
        <dependency>
            <groupId>org.eclipse.jetty</groupId>
            <artifactId>jetty-servlet</artifactId>
            <version>9.4.43.v20210629</version>
            <scope>provided</scope>
        </dependency>
        
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-servlet-initializer</artifactId>
            <version>4.7.1.Final</version>
        </dependency>
        
    </dependencies>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>
</project>

EDIT: Solution was to add the following dependency:

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jackson2-provider</artifactId>
            <version>4.7.1.Final</version>
        </dependency>