Binding custom data type transmit null to converter - kotlin

Question

I'm using Jooq and Kotlin in my project. I have object EventEnvelope in which field of type Event is composed. I want to store this field as JSON in my DB (postgres). I prepared jooq custom datatype bindings and converter as it is described here -> https://www.jooq.org/doc/3.10/manual/code-generation/custom-data-type-bindings/
Below I paste converter, binding and gradle generator code.
My questions are:
Is it ok to use kotlin non null types with jooq bindings?
Is this configuration ok? What should I change?
When I want to store value my converter gets null in from func. I don't why is that.
I am out of ideas what should I do to fix it.
class JSONEventConverter constructor(
private val objectMapper: ObjectMapper,
private val schemaMatcher: SchemaMatcher
) : Converter<Any, Event> {
override fun from(databaseObject: Any): Event {
return schemaMatcher.parse(databaseObject.toString())
}
override fun to(userObject: Event): Any {
return objectMapper.writeValueAsString(userObject)
}
override fun fromType(): Class<Any> {
return Any::class.java
}
override fun toType(): Class<Event> {
return Event::class.java
}
companion object {
fun create(): JSONEventConverter {
return JSONEventConverter(jacksonObjectMapper(),
SchemaMatcher.create())
}
}
}
class PostgresJSONEventBinding : Binding<Any, Event> {
override fun register(ctx: BindingRegisterContext<Event>?) {
ctx!!.statement().registerOutParameter(ctx.index(), Types.VARCHAR)
}
override fun sql(ctx: BindingSQLContext<Event>?) {
ctx!!.render().visit(DSL.`val`(ctx.convert(converter())
.value())).sql("::json")
}
override fun converter(): Converter<Any, Event> {
return JSONEventConverter.create()
}
override fun get(ctx: BindingGetResultSetContext<Event>?) {
ctx!!.convert(converter())
.value(ctx.resultSet().getString(ctx.index()))
}
override fun get(ctx: BindingGetStatementContext<Event>?) {
ctx!!.convert(converter())
.value(ctx.statement().getString(ctx.index()))
}
override fun get(ctx: BindingGetSQLInputContext<Event>?) {
throw SQLFeatureNotSupportedException()
}
override fun set(ctx: BindingSetStatementContext<Event>?) {
ctx!!.statement().setString(ctx.index(),
Objects.toString(ctx.convert(converter()).value(), null))
}
override fun set(ctx: BindingSetSQLOutputContext<Event>?) {
throw SQLFeatureNotSupportedException()
}
}
generator {
name = 'org.jooq.util.DefaultGenerator'
strategy {
name = 'org.jooq.util.DefaultGeneratorStrategy'
}
database {
name = 'org.jooq.util.postgres.PostgresDatabase'
schemata {
schema {
inputSchema = someSchema
}
schema {
inputSchema = otherSchema
}
}
forcedTypes {
forcedType {
userType = 'package.Event'
binding = 'package.PostgresJSONEventBinding'
expression = 'someSchema\\.event_store\\.event'
}
}
}
generate {
relations = true
deprecated = false
records = true
immutablePojos = true
fluentSetters = true
}
target {
packageName = appName
}
}

Answer 1

Is it ok to use kotlin non null types with jooq bindings?
jOOQ (or any Java library) will not respect your Kotlin non-nullable guarantees and might produce null values where you wouldn't expect them. So, perhaps it's not a good idea after all.
At the interface between jOOQ and your code, you must ensure yourself that this cannot happen.
Is this configuration ok? What should I change?
That's an open ended question. If you have any specific questions, please ask.
When I want to store value my converter gets null in from func. I don't why is that.
There are not enough infos in your question to help you about this

Answer 2

Ok so in my case it was about java-kotlin interoperability between nullable types in Java and non-null types in kotlin. All I had to do was implementing converter using nullable types in kotlin (the ones with ?).
Correct converter look like this:
class JSONEventConverter constructor(
private val objectMapper: ObjectMapper,
private val schemaMatcher: SchemaMatcher
) : Converter<Any, Event> {
override fun from(databaseObject: Any?): Event? {
return databaseObject?.let { schemaMatcher.parse(it.toString()) }
}
override fun to(userObject: Event?): Any? {
return userObject?.let { objectMapper.writeValueAsString(it) }
}
override fun fromType(): Class<Any> {
return Any::class.java
}
override fun toType(): Class<Event> {
return Event::class.java
}
companion object {
fun create(): JSONEventConverter {
return JSONEventConverter(serializingObjectMapper(),
SchemaMatcher.create())
}
}
}