ActiveObjects v1.1.5 in jira 7.0.4 error

[SALAH Abderraouf]

this is my code 

package io.codeclou.kitchen.duty.rest;

import com.atlassian.activeobjects.external.ActiveObjects;
import com.atlassian.plugins.rest.common.security.AnonymousAllowed;
import com.atlassian.sal.api.transaction.TransactionCallback;
import io.codeclou.kitchen.duty.ao.Week;

import javax.inject.Named;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

@Named
@Path("/planning")
public class KitchenDutyPlanningResource {

    private ActiveObjects activeObjects;

    public KitchenDutyPlanningResource(ActiveObjects activeObjects) {
        this.activeObjects = activeObjects;
    }

    public KitchenDutyPlanningResource() {
    }


    @GET
    @Path("/persistTest")
    @Produces({MediaType.APPLICATION_JSON})
    @AnonymousAllowed
    public Response persistTest() {
        activeObjects.executeInTransaction(new TransactionCallback<Week>()
        {
            @Override
            public Week doInTransaction()
            {
                final Week testWeek = activeObjects.create(Week.class);
                testWeek.setWeek(42);
                testWeek.save();
                return testWeek;
            }
        });
        return Response.ok("ok").build();
    }

    @GET
    @Path("/health")
    @Produces({MediaType.APPLICATION_JSON})
    @AnonymousAllowed
    public Response health() {
        return Response.ok("ok").build();
    }

}  and i got this error

 <status-code>500</status-code>

    <stack-trace>java.lang.NullPointerException&#xD;

    at io.codeclou.kitchen.duty.rest.KitchenDutyPlanningResource.persistTest(KitchenDutyPlanningResource.java:34)&#xD;

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)&#xD;

    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)&#xD;

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)&#xD;

    at java.lang.reflect.Method.invoke(Method.java:498)&#xD;

    at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$ResponseOutInvoker$1.invoke(DispatchProviderHelper.java:234)&#xD;

    at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper$1.intercept(DispatchProviderHelper.java:100)&#xD;

    at com.atlassian.plugins.rest.common.interceptor.impl.DefaultMethodInvocation.invoke(DefaultMethodInvocation.java:61)&#xD;

    at com.atlassian.plugins.rest.common.expand.interceptor.ExpandInterceptor.intercept(ExpandInterceptor.java:38)&#xD;

    at com.atlassian.plugins.rest.common.interceptor.impl.DefaultMethodInvocation.invoke(DefaultMethodInvocation.java:61)&#xD;

    at com.atlassian.plugins.rest.common.interceptor.impl.DispatchProviderHelper.