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add experimentalDeserializationBackend switch
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@k163377
k163377 committed May 3, 2021
1 parent 2bc2743 commit 75a1c3e
Showing 1 changed file with 161 additions and 2 deletions.
163 changes: 161 additions & 2 deletions src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinValueInstantiator.kt
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Expand Up @@ -3,15 +3,24 @@ package com.fasterxml.jackson.module.kotlin
import com.fasterxml.jackson.databind.BeanDescription
import com.fasterxml.jackson.databind.DeserializationConfig
import com.fasterxml.jackson.databind.DeserializationContext
import com.fasterxml.jackson.databind.MapperFeature
import com.fasterxml.jackson.databind.deser.SettableBeanProperty
import com.fasterxml.jackson.databind.deser.ValueInstantiator
import com.fasterxml.jackson.databind.deser.ValueInstantiators
import com.fasterxml.jackson.databind.deser.impl.NullsAsEmptyProvider
import com.fasterxml.jackson.databind.deser.impl.PropertyValueBuffer
import com.fasterxml.jackson.databind.deser.std.StdValueInstantiator
import com.fasterxml.jackson.databind.introspect.AnnotatedConstructor
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod
import java.lang.reflect.Constructor
import java.lang.reflect.Method
import java.lang.reflect.TypeVariable
import kotlin.reflect.KParameter
import kotlin.reflect.KType
import kotlin.reflect.full.extensionReceiverParameter
import kotlin.reflect.full.instanceParameter
import kotlin.reflect.full.valueParameters
import kotlin.reflect.jvm.isAccessible
import kotlin.reflect.jvm.javaType

internal class KotlinValueInstantiator(
Expand All @@ -24,8 +33,7 @@ internal class KotlinValueInstantiator(
private val strictNullChecks: Boolean,
private val experimentalDeserializationBackend: Boolean
) : StdValueInstantiator(src) {
@Suppress("UNCHECKED_CAST")
override fun createFromObjectWith(
private fun experimentalCreateFromObjectWith(
ctxt: DeserializationContext,
props: Array<out SettableBeanProperty>,
buffer: PropertyValueBuffer
Expand Down Expand Up @@ -109,6 +117,157 @@ internal class KotlinValueInstantiator(
}
}

@Suppress("UNCHECKED_CAST")
private fun conventionalCreateFromObjectWith(
ctxt: DeserializationContext,
props: Array<out SettableBeanProperty>,
buffer: PropertyValueBuffer
): Any? {
val callable = when (_withArgsCreator) {
is AnnotatedConstructor -> cache.kotlinFromJava(_withArgsCreator.annotated as Constructor<Any>)
is AnnotatedMethod -> cache.kotlinFromJava(_withArgsCreator.annotated as Method)
else -> throw IllegalStateException("Expected a constructor or method to create a Kotlin object, instead found ${_withArgsCreator.annotated.javaClass.name}")
} ?: return super.createFromObjectWith(
ctxt,
props,
buffer
) // we cannot reflect this method so do the default Java-ish behavior

if (callable.extensionReceiverParameter != null) {
// we shouldn't have an instance or receiver parameter and if we do, just go with default Java-ish behavior
return super.createFromObjectWith(ctxt, props, buffer)
}

val propCount = props.size + if (callable.instanceParameter != null) 1 else 0

var numCallableParameters = 0
val callableParameters = arrayOfNulls<KParameter>(propCount)
val jsonParamValueList = arrayOfNulls<Any>(propCount)

if (callable.instanceParameter != null) {
val possibleCompanion = callable.instanceParameter!!.type.erasedType().kotlin

if (!possibleCompanion.isCompanion) {
// abort, we have some unknown case here
return super.createFromObjectWith(ctxt, props, buffer)
}

// TODO: cache this lookup since the exception throwing/catching can be expensive
jsonParamValueList[numCallableParameters] = try {
possibleCompanion.objectInstance
} catch (ex: IllegalAccessException) {
// fallback for when an odd access exception happens through Kotlin reflection
val companionField = possibleCompanion.java.enclosingClass.fields.firstOrNull { it.name == "Companion" }
?: throw ex
val accessible = companionField.isAccessible
if ((!accessible && ctxt.config.isEnabled(MapperFeature.CAN_OVERRIDE_ACCESS_MODIFIERS)) ||
(accessible && ctxt.config.isEnabled(MapperFeature.OVERRIDE_PUBLIC_ACCESS_MODIFIERS))
) {
companionField.isAccessible = true
}
companionField.get(null) ?: throw ex
}

callableParameters[numCallableParameters] = callable.instanceParameter
numCallableParameters++
}

callable.valueParameters.forEachIndexed { idx, paramDef ->
val jsonProp = props[idx]
val isMissing = !buffer.hasParameter(jsonProp)

if (isMissing && paramDef.isOptional) {
return@forEachIndexed
}

var paramVal = if (!isMissing || paramDef.isPrimitive() || jsonProp.hasInjectableValueId()) {
val tempParamVal = buffer.getParameter(jsonProp)
if (nullIsSameAsDefault && tempParamVal == null && paramDef.isOptional) {
return@forEachIndexed
}
tempParamVal
} else {
// trying to get suitable "missing" value provided by deserializer
jsonProp.valueDeserializer?.getNullValue(ctxt)
}

if (paramVal == null && ((nullToEmptyCollection && jsonProp.type.isCollectionLikeType) || (nullToEmptyMap && jsonProp.type.isMapLikeType))) {
paramVal = NullsAsEmptyProvider(jsonProp.valueDeserializer).getNullValue(ctxt)
}

val isGenericTypeVar = paramDef.type.javaType is TypeVariable<*>
val isMissingAndRequired = paramVal == null && isMissing && jsonProp.isRequired
if (isMissingAndRequired ||
(!isGenericTypeVar && paramVal == null && !paramDef.type.isMarkedNullable)) {
throw MissingKotlinParameterException(
parameter = paramDef,
processor = ctxt.parser,
msg = "Instantiation of ${this.valueTypeDesc} value failed for JSON property ${jsonProp.name} due to missing (therefore NULL) value for creator parameter ${paramDef.name} which is a non-nullable type"
).wrapWithPath(this.valueClass, jsonProp.name)
}

if (strictNullChecks && paramVal != null) {
var paramType: String? = null
var itemType: KType? = null
if (jsonProp.type.isCollectionLikeType && paramDef.type.arguments.getOrNull(0)?.type?.isMarkedNullable == false && (paramVal as Collection<*>).any { it == null }) {
paramType = "collection"
itemType = paramDef.type.arguments[0].type
}

if (jsonProp.type.isMapLikeType && paramDef.type.arguments.getOrNull(1)?.type?.isMarkedNullable == false && (paramVal as Map<*, *>).any { it.value == null }) {
paramType = "map"
itemType = paramDef.type.arguments[1].type
}

if (jsonProp.type.isArrayType && paramDef.type.arguments.getOrNull(0)?.type?.isMarkedNullable == false && (paramVal as Array<*>).any { it == null }) {
paramType = "array"
itemType = paramDef.type.arguments[0].type
}

if (paramType != null && itemType != null) {
throw MissingKotlinParameterException(
parameter = paramDef,
processor = ctxt.parser,
msg = "Instantiation of $itemType $paramType failed for JSON property ${jsonProp.name} due to null value in a $paramType that does not allow null values"
).wrapWithPath(this.valueClass, jsonProp.name)
}
}

jsonParamValueList[numCallableParameters] = paramVal
callableParameters[numCallableParameters] = paramDef
numCallableParameters++
}

return if (numCallableParameters == jsonParamValueList.size && callable.instanceParameter == null) {
// we didn't do anything special with default parameters, do a normal call
super.createFromObjectWith(ctxt, jsonParamValueList)
} else {
val accessible = callable.isAccessible
if ((!accessible && ctxt.config.isEnabled(MapperFeature.CAN_OVERRIDE_ACCESS_MODIFIERS)) ||
(accessible && ctxt.config.isEnabled(MapperFeature.OVERRIDE_PUBLIC_ACCESS_MODIFIERS))
) {
callable.isAccessible = true
}
val callableParametersByName = linkedMapOf<KParameter, Any?>()
callableParameters.mapIndexed { idx, paramDef ->
if (paramDef != null) {
callableParametersByName[paramDef] = jsonParamValueList[idx]
}
}
callable.callBy(callableParametersByName)
}
}

override fun createFromObjectWith(
ctxt: DeserializationContext,
props: Array<out SettableBeanProperty>,
buffer: PropertyValueBuffer
): Any? = if (experimentalDeserializationBackend) {
experimentalCreateFromObjectWith(ctxt, props, buffer)
} else {
conventionalCreateFromObjectWith(ctxt, props, buffer)
}

private fun KParameter.isPrimitive(): Boolean {
return when (val javaType = type.javaType) {
is Class<*> -> javaType.isPrimitive
Expand Down

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