Spring MVC jackson auto serialize? - spring-mvc

Question

I would like to serialize an object with jackson in spring MVC.
I have a controller which returns an ObjectTest1 which has a property ObjectTest2.
public class ObjectTest1{
private ObjectTest2;
// setters getters...
}
public class ObjectTest2{
private String value;
// setters getters...
}
public #ResponseBody ObjectTest1 test() throws IOException ...
I have a mapper and I have a serializer for ObjectTest2 and I've annotated the ObjectTest1.getObjectTest2 method with #JsonSerialize(using = ObjectTest2.class).
It works correctly!
But I want to use this serializer in a lot of Object, not just in ObjectTest1.
What should I do to avoid put annotation every getter method? Can use spring this serializer automatically for all properites which is ObjectTest2?
UPDATED:
I've already use this in my code:
<mvc:annotation-driven>
In ajax response Objects generated correctly as json.
Maybe I should try to explain another way.
So.
I have these objects:
public class DTO{
private InnerThing innerThing;
#JsonSerialize(using=ThingSerializer.class)
public InnerThing getThing(){...}
}
public class InnerThing{
private String value;
}
Generated json looks like:
{"innerThing":{"value":"something"}}
Afther when I've written a serializer, json is:
{"innerThing":"something"}
It is OK, but to get the second version of json I must annotate the getInnerThing method in DTO class with #JsonSerialize...
I don't want to annotate all methods where I use InnerThing as a property.
So my question is, can spring auto serialize every property which type is InnerThing?

Answer 1

By default, Spring will handle serialization and de-serialization of JSON automatically if you add Jackson to the classpath and you use either <mvc:annotation-driven> or #EnableWebMvc.
Links to the Spring Reference Docs:
Spring 3.0: <mvc:annotation-driven>
Spring 3.1: <mvc:annotation-driven> and #EnableWebMvc

Answer 2

You want Jackson to always use your custom JsonSerializer or JsonDeserializer to serialize/deserialize a specific type?
I ended up writing a custom Jackson module to let Jackson find serializers and deserializers that are Spring beans.
I am using Spring 3.1.2 and Jackson 2.0.6
Simplified version:
public class MyObjectMapper extends ObjectMapper {
#Autowired
public MyObjectMapper(ApplicationContext applicationContext) {
SpringComponentModule sm = new SpringComponentModule(applicationContext);
registerModule(sm);
}
}
Module:
public class SpringComponentModule extends Module {
private ApplicationContext applicationContext;
public SpringComponentModule(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
#Override public String getModuleName() {
return "jackson-spring-component";
}
#Override public Version version() {
return SpringComponentModuleVersion.instance.version();
}
#Override
public void setupModule(SetupContext context) {
context.addSerializers(new SpringComponentSerializers(this.applicationContext));
context.addDeserializers(new SpringComponentDeserializers(this.applicationContext));
}
}
ComponentSerializer class:
public class SpringComponentSerializers extends Serializers.Base {
private ApplicationContext applicationContext;
public SpringComponentSerializers(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
#Override
public JsonSerializer<?> findSerializer(SerializationConfig config, JavaType type, BeanDescription beanDesc) {
Class<?> raw = type.getRawClass();
Map<String,JsonSerializer> beanSet = applicationContext.getBeansOfType(JsonSerializer.class);
for(String beanName : beanSet.keySet()) {
JsonSerializer<?> serializer = beanSet.get(beanName);
if(serializer.handledType().isAssignableFrom(raw)) {
return serializer;
}
}
return null;
}
}