Jersey and guice and nice json

Question

I have a project that uses Jersey 1.7, Guice 3.0 and has some annotated JAXB classes that are serialized through resources for XML and JSON. I would like to set up JSON output using ContextResolver , as suggested in several questions here on SO, as well as in the Jersey User Guide . This includes creating a JSONJAXBContext as follows:

 public class JaxbResolver implements ContextResolver<JAXBContext> { private final JAXBContext context; public JaxbResolver() throws Exception { this.ctx = new JSONJAXBContext( JSONConfiguration. natural(). humanReadableFormatting(true). build(), Resource1.class, Resource2.class); } /* ... */ } 

My problem is that some of my resource classes have dependencies that Guice needs to introduce, for example:

 public class DisplayConfigResource { private final ConfigRunner cr; @com.google.inject.Inject public DisplayConfigResource(ConfigRunner cr) { this.cr = cr; } /* ... */ } 

If I remove my JaxbResolver from the game, everything will be fine, except that I have no control over the generated JSON (and by default it is really strange, for example, removing [] from singleton collections, ...). So, it seems common sense to hook up ContextResolver like mine in Jersey so that I can configure JSON for what I like. But

• the JSONJAXBContext class really likes to have no-arg constructors on resources, and
• My resources really would like their dependencies to be injected into their constructors.

So my question is how to resolve this situation, and are Jersey, Guise, and John playing well together?

Answer 1

You can also use Jackson instead of JAXB for Marshal / unmarshal JSON. It uses the same annotations @XmlRootElement , @XmlType etc., and it produces more standard output (and does not need these useful ContextResolver materials).

First configure your web.xml:

 <servlet> <servlet-name>jersey</servlet-name> <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class> <init-param> <param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name> <param-value>true</param-value> </init-param> </servlet> 

Then add the jersey-json dependency to your pom.xml:

 <dependency> <groupId>com.sun.jersey</groupId> <artifactId>jersey-json</artifactId> <version>1.7</version> </dependency> 

Answer 2

I had a similar problem and solved it by creating a custom JAXBContextResolver and manually specifying which classes would play well with json serialization:

 @Provider public class JAXBContextResolver implements ContextResolver<JAXBContext> { private JAXBContext context; private Class<?>[] types = {DtoIdNazov.class, DtoLokalitaPoloha.class, DtoListRestauracie.class, DtoDetailRestauracia.class}; public JAXBContextResolver() throws Exception { JSONConfiguration jsonConfiguration = JSONConfiguration.natural().build(); this.context = new JSONJAXBContext(jsonConfiguration, types); } public JAXBContext getContext(Class<?> objectType) { for (Class<?> type : types) { if (type == objectType) { return context; } } return null; } }