How can I import kotlin functions to java classes?-CodePudding

I am currently using KotlinModule class in my java file by importing import com.fasterxml.jackson.module.kotlin.KotlinModule;, but in recent jackson library upgrade (using 2.13) it is has been depricated. I was looking for the new convention, and came across this https://github.com/FasterXML/jackson-module-kotlin#usage

however I am not able to load the recommended functions in java file, i think that only works in Kotlin file. Is there an alternative?

CodePudding user response：

This module uses Kotlin extension functions, they are all defined in an Extensions.kt file and as such are accessible by importing the ExtensionsKt class. For example :

import com.fasterxml.jackson.module.kotlin.ExtensionsKt;
import com.fasterxml.jackson.databind.ObjectMapper;

ObjectMapper mapper = ExtensionsKt.jacksonObjectMapper();

If the method extends a type, for example in Kotlin :

val mapper = ObjectMapper().registerKotlinModule()

The method is defined in kotlin as :

fun ObjectMapper.registerKotlinModule(): ObjectMapper

It will be converted in java to :

public static final ObjectMapper registerKotlinModule(@NotNull ObjectMapper $this$registerKotlinModule)

So to use it, you need to pass the extended type :

ObjectMapper mapper = ExtensionsKt.registerKotlinModule(new ObjectMapper());