currently I'm designing a domain model for an application. I created a simple value object that's basically just a wrapper around a string enhanced with some business logic.
Now the default behaviour of jackson is to render the object like
"routerId": {
"routerId": "aa:aa:aa:aa:aa:aa"
}
for
@Embeddable
data class RouterId(val routerId: String) {
init {
val octets = routerId.split(":")
if (octets.size != 6) {
throw IllegalArgumentException("$routerId does not consist of 6 octets")
}
for (octet in octets) {
Integer.parseInt(octet, 16)
}
}
}
I stumbeld accross http://docs.spring.io/spring-data/rest/docs/2.6.3.RELEASE/reference/html/#_adding_custom_de_serializers_to_jackson_s_objectmapper and tried to supply my custom jackson module to handle serialization with
class NicemediaModule : SimpleModule("NicemediaModule") {
override fun setupModule(context: SetupContext?) {
val serializers = SimpleSerializers()
serializers.addSerializer(RouterId::class.java, RouterIdSerializer())
context?.addSerializers(serializers)
}
}
private class RouterIdSerializer : StdSerializer<RouterId>(RouterId::class.java) {
override fun serialize(value: RouterId?, gen: JsonGenerator?, provider: SerializerProvider?) {
gen?.writeString(value?.routerId)
}
}
and
@Configuration
open class SpringDataRestConfiguration : RepositoryRestConfigurerAdapter() {
override fun configureJacksonObjectMapper(objectMapper: ObjectMapper?) {
objectMapper?.registerModule(NicemediaModule())
}
}
but this only leads to
"routerId": {
"content": "aa:aa:aa:aa:aa:aa"
}
Could anyone point out what I would have to do to serialize the RouterId just to a plain string like "routerId": "aa:aa:aa:aa:aa:aa"?
Edit:
I added @Component to my SimpleModule so that Spring Boot loads it by default and wrote a litte test to see if the ObjectMapper works.
@SpringBootTest
@RunWith(SpringRunner::class)
class JsonSerializationTest {
@Autowired
private lateinit var mapper: ObjectMapper
@Test
fun serializeRouterId() {
val routerId: String = "11:11:11:11:11:11"
assertEquals("\"$routerId\"", mapper.writeValueAsString(RouterId(routerId)))
}
}
works quite fine. This may be an indicator that my code is working the whole time but Spring Data REST fails to serialize my model at some point.
