Can RestEasy serialize a POJO for a @GET method?

Question

We use Resteasy and have problems figuring how to call some @GET methods.

If the interface for the method only has simple parameters, there is no problem. Ex:

@GET
@Path("/test/{myparam}")
public FacetQueryResultImpl testMethod(@PathParam("myparam")String myparam);

But if we try to use a POJO as the parameter, it seems RestEasy is not able to serialize it as querystring parameters. Ex:

@GET
@Path("/testGet")
public FacetQueryResultImpl testMethod(ParamPojo myparam);

or

@GET
@Path("/testGet")
public FacetQueryResultImpl testMethod(@QueryParam("myparam")ParamPojo myparam);

(with, ParamPojo.java:)

public class ParamPojo
{
    private String name;
    private String description;
    (...)
}

When we try this, sometimes the services are not found and sometimes we get a "A GET request cannot have a body." exception.

Using @POST we are able to use a POJO has the parameter, but some of our methods don't modify anything on the server, and therefore should use @GET.

A workaround is to "explode" the ParamPojo, and use all of its properties as separated parameters for the method. But this removes the "Easy" part of "RestEasy", doesn't it?

Answer 1

You must use the @org.jboss.resteasy.annotations.Form annotation on your method parameter. http://docs.jboss.org/resteasy/docs/2.2.1.GA/userguide/html_single/#_Form

Example:

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.QueryParam;

import junit.framework.Assert;

import org.jboss.resteasy.annotations.Form;
import org.jboss.resteasy.core.Dispatcher;
import org.jboss.resteasy.mock.MockDispatcherFactory;
import org.jboss.resteasy.mock.MockHttpRequest;
import org.jboss.resteasy.mock.MockHttpResponse;
import org.junit.Test;

public class TestCase {
    @Path("/")
    public static class Service {

        @Path("")
        @GET
        public String get(@Form ValueObject vo){
            return vo.getParam();
        }
    }

    public static class ValueObject {
        @QueryParam("myparam")
        private String param;

        public String getParam() {
            return param;
        }
    }

    @Test
    public void test() throws Exception {
        Dispatcher dispatcher = MockDispatcherFactory.createDispatcher();
        dispatcher.getRegistry().addSingletonResource(new Service());

        MockHttpRequest request = MockHttpRequest.get("/?myparam=somevalue");
        MockHttpResponse response = new MockHttpResponse();

        dispatcher.invoke(request, response);

        Assert.assertEquals("somevalue", response.getContentAsString());
    }
}

Answer 2

For binding the multiple queryParam into a single object we need to add @Form <POJO CLASS> as a arguments in response method. It works fine for us.

@GET    
@Path("/")  
@Produces("application/json")
@Consumes("application/json")
public Response search(@Form CatalogSearchRequest reqObject) {
    System.out.println("Entered into service" + reqObject.getAttribute());
}

POJO class should contain @QueryParam("") for every attributes, for example:

@QueryParam("pageSize")
public Integer pageSize;

@QueryParam("page")
public Integer page;

public Integer getPageSize() {
    return pageSize;
}

public void setPageSize(Integer pageSize) {
    this.pageSize = pageSize;
}

public Integer getPage() {
    return page;
}

public void setPage(Integer page) {
    this.page = page;
}