JsonView documentation

[Alfredo]

Andrés,

I am trying to use the JsonView class but can't find any documentation. I guess I should override the renderMergedOutputModel(..) method, but I don't know what exactly do. Could you please provide a small code snippet?

Thanks

[Alfredo]

After a while, now is working. The Spring configuration I have is as follows:

The lms-views.xml file:
        <bean id="jsonView" class="net.sf.json.spring.web.servlet.view.JsonView" />

The lms-servlet.xml
    <bean id="myViewResolver" class="org.springframework.web.servlet.view.XmlViewResolver">
        <property name="location" value="classpath:lms-views.xml" />
        <property name="order" value="0" />
    </bean>

    <bean id="jsonController" class="com.myapp.JsonController">
        <property name="catalogService" ref="catalogService" />
    </bean>

The jsonController looks like this:
    protected ModelAndView handleRequestInternal(HttpServletRequest request,
            HttpServletResponse response) throws Exception {
       
        Map model = new HashMap();
        model.put("paises", catalogService.getPaises());
       
        return new ModelAndView("jsonView", model);
    }

Please let me know if this is the right configuration.

[aalmiray]

Yes, that would be the most common way. Only if you need to do some pre-processing of your data before output that you'll be concerned with the other protected methods from JsonView.

Glad you got it working :)

Cheers,
Andres

[Alfredo]

I wonder how I could exclude nested properties, for example I have this:

MainObject.propertya.propertyb

What would I do in order to exclude from propertya down the hierarchy?

I realized that is not possible to use dot notation  (as shown below) in the "excludedeProperties" bean  property.

<bean id="jsonView" class="net.sf.json.spring.web.servlet.view.JsonView">
<property name="excludedProperties" value="propertya.propertyb" /> 
</bean>

What would be the option to exclude nested properties?

[aalmiray]

Alfredo,

There are several ways to do it :) The easiest one is registering a String[] of exclusions via excludedProperties, but it has a drawback, say you write something like

<bean id="jsonView" class="net.sf.json.spring.web.servlet.view.JsonView">
<property name="excludedProperties" value="propertyb,propertyc" /> 
</bean>

then for any bean property (not just MainObject) that matches that list will be excluded.

There are other alternatives as I previously mentioned, you can find a description of them at the following link
http://jroller.com/aalmiray/entry/json_lib_hibernate_tips_and

You'll have to create an instance of JsonConfig, set the desired configuration props/flags and wire it up into your views.

Cheers,
Andres

[Alfredo]

Andrés,

Thanks so much for your help, is highly appreciated. Now only one problem remains.

I have two JsonBeanProcessors corresponding to two of my domain classes and a JsonBeanProcessorMatcher as you mention in your blog post.

My domain hierarchy looks like this --> User.Company.Category <--
The JsonBeanProcessors correspond to User and Company classes. The Company's JsonBeanProcessor does not include the category property, but I am still getting the Hibernate's LazyInitializationException regarding to Company's category property. Why?

If in User's JsonBeanProcessor I comment out the code as follows, the Json string is generated fine.

...
User user = (User) bean;
return new JSONObject()
.element("name", user.getName())
//.element("company", user.getCompany()) <-- Commented out
.element("mail", user.getEmail());
...

Why doesn't Json-lib take into account the Company's JsonBeanProcessor?

[aalmiray]

Alfredo,

Could you post the code of your JsonBeanProcessorMatcher? thanks!

Andres

[Alfredo]

Yes, of course, here it is:

    private class MyJsonBeanProcessorMatcher extends JsonBeanProcessorMatcher {

        @SuppressWarnings("unchecked")
        @Override
        public Object getMatch(Class target, Set set) {
            for (Object match : set) {
                if (((Class) match).isAssignableFrom(target)) {
                    return match;
                }
            }
            return null;
        }
       
    }

[Alfredo]

Andés,

Te problem occurs when the method JSONObject.element() is called from UserJsonBeanProcessor, see the implementation:

   public JSONObject element( String key, Object value ) {
      return element( key, value, new JsonConfig() );
   }
  
Is created a new JsonConfig object, with an empty beanProcessorMap.

[Alfredo]

Now is working fine, I haven't seen the method:

public JSONObject element( String key, Object value, JsonConfig jsonConfig )

Thanks a lot and congratulations for such great framework!!