Problems with no-arg plugin + JsonIgnore + Kotlin 1.1

[mhlz]

I tried updating an internal project to Kotlin 1.1, but I encountered an issue with one of our data classes. It seems that in some circumstances deserializing doesn't work even though it worked fine with Kotlin 1.0.6.

I uploaded a minimal example project that demonstrates the error here: https://github.com/mhlz/jackson-module-kotlin-issue

If you change the kotlin.version property in the pom.xml to 1.0.6 it works fine. But with 1.1.0 it crashes with the following exception:

Exception in thread "main" com.fasterxml.jackson.databind.JsonMappingException: Could not find creator property with name 'innerTest' (in class Test)
 at [Source: 
{
    "innerTest": {
        "str": "str",
        "otherStr": "otherStr"
    }
}
; line: 2, column: 1]
	at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:270)
	at com.fasterxml.jackson.databind.DeserializationContext.reportMappingException(DeserializationContext.java:1234)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.addBeanProps(BeanDeserializerFactory.java:551)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.buildBeanDeserializer(BeanDeserializerFactory.java:226)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer(BeanDeserializerFactory.java:141)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:403)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:349)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:264)
	at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
	at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)
	at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:476)
	at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:3899)
	at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3794)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2842)
	at MainKt.main(Main.kt:36)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

I figured out that removing the @field:JsonIgnore annotation makes the exception go away. The same thing happens with @get:JsonIgnore as well.

I hope the example project gives enough info to debug this issue properly, as I have no idea what could cause this problem.

After investigating more this issue does not occur with module-kotlin 2.8.6 and databind 2.8.6. Those work fine with Kotlin 1.1.

[apatrida]

thanks, I'll look at it.

[jamesbassett]

We had a similar issue with Kotlin 1.0.6 and Jackson 2.8.7. @JsonIgnore'd constructor properties were causing all properties to be ignored. We've reverted to Jackson 2.8.6 for now. Interestingly, moving them to normal (non-constructor) properties fixed the issue.

[apatrida]

@mhlz a side note, in your code you can do:

 val test: Test = mapper.readValue(testJson)

or

 val test = mapper.readValue<Test>(testJson)

instead of passing Test::class.java to the readValue() method. It is a better pattern since it'll reify and catch all generics in the future case where you have a class with generics, best to be in the same pattern.

[apatrida]

@cowtowncoder this one is odd, the plugin does the same behavior as it has done for a long time, but with databind 2.8.7 it breaks, while in 2.8.6 it works fine. The plugin says that there is a creator annotation on the correct constructor, and has returned the correct name for the parameters including the one that it says is missing. I don't have a java-only reproducible case, but you can debug the above linked project (intellij+kotlin plugin, load pom.xml and debug the databinding code). Kotlin module works at 2.8.6 or 2.8.7 versions, it is only the databind version number change that breaks the process.

[apatrida]

@cowtowncoder see FasterXML/jackson-databind#1572

[apatrida]

This is fixed in 2.8.8-SNAPSHOT of databind, so closing issue here, track FasterXML/jackson-databind#1572 for release and additional information, but should be fine in 2.8.8 and 2.9.x branch