Inject ObjectMapper instance via @context into REST method

Inject ObjectMapper instance via @Context into REST method

package com.tomtom.dcs.springconfig;

import java.util.Arrays;

import javax.ws.rs.core.Application;
import javax.ws.rs.ext.RuntimeDelegate;

import org.apache.cxf.bus.spring.SpringBus;
import org.apache.cxf.endpoint.Server;
import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.DependsOn;

import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
import com.fasterxml.jackson.jaxrs.xml.JacksonXMLProvider;
import com.tomtom.dcs.service.AccountsService;
import com.tomtom.dcs.service.GreetingsService;
import com.tomtom.dcs.service.PackagesService;
import com.tomtom.dcs.service.PackageListService;


@Configuration
public class CxfConfig
{
    @Autowired
    GreetingsService greetingsService;

    @Autowired
    PackageListService packageListService;

    @Autowired
    AccountsService accountsService;

    @Autowired
    PackagesService packagesService;

    @Bean(destroyMethod = "shutdown")
    public SpringBus cxf()
    {
        return new SpringBus();
    }

    @Bean
    @DependsOn("cxf")
    public Server jaxRsServer()
    {
        JAXRSServerFactoryBean factory =
            RuntimeDelegate.getInstance().createEndpoint(new Application(), JAXRSServerFactoryBean.class);
        factory.setServiceBeans(Arrays.<Object>asList(
            greetingsService,
            packageListService,
            accountsService,
            packagesService));
        factory.setAddress("/api" + factory.getAddress());
        factory.setProviders(Arrays.<Object>asList(
            new JacksonJsonProvider(),
            new JacksonXMLProvider(),
            new ObjectMapperResolver()));
        return factory.create();
    }

}

ObjectMapperResolver

package com.tomtom.dcs.springconfig;

import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;


/**
 * A JAX-RS {@link Provider} used to provide an Jackson {@link ObjectMapper} to
 * all root resource class. Is automatically used by {@link JacksonJsonProvider}
 * and can be accessed by every method via {@link Context @Context} method parameter
 * injection for custom usage.
 *
 * @author grundleo
 */
@Provider
@Produces(MediaType.APPLICATION_JSON)
public class ObjectMapperResolver implements ContextResolver<ObjectMapper>
{

    private ObjectMapper objectMapper;

    public ObjectMapperResolver()
    {
        super();
        objectMapper = new ObjectMapper();
    }

    @Override
    public ObjectMapper getContext(Class<?> type)
    {
        return objectMapper;
    }

}

RestService

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    @Path("packagelists/{id}")
    @Override
    public DcsPackageList updatePackageList(String dcsPackageList,
                                            @PathParam("id") String packageListId,
                                            @Context ContextResolver<ObjectMapper> objectMapperResolver)
    {
        // access the commonly used ObjectMapper: some JAX-RS magic to use always the same ObjectMapper instance
        ObjectMapper om = objectMapperResolver.getContext(DcsPackageList.class);
        
        // read the object to be updated
        DcsPackageList dcsPackageListToUpdate = packageListDao.findById(Long.valueOf(packageListId));
        
        // do something custom with the mapper
        // do a partial update: update the loaded object with the incoming values
        om.readerForUpdating(dcsPackageListToUpdate).readValue(dcsPackageList);
        
        // update it in the database
        packageListDao.update(dcsPackageListToUpdate);
    }