Wrong serialized LocalDateTime with OpenAPI Generator

I'm using OpenAPI Generator to create a client, but when I trying to make a POST request is serialized the LocalDateTime like a integer array, looks like

{
  "startDate": [ 2019, 11, 13, 0, 0 ],
  "endDate": [ 2020, 12, 31, 0, 0 ]
}

I'm waiting for this result, parse like a ISO string

{
  "startDate": "2019-11-13T00:00",
  "endDate": "2020-12-31T00:00"
}

My gradle configuration is this:

dependencies {
  compile 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.10.3'
  classpath 'org.openapitools:openapi-generator-gradle-plugin:4.2.3'
}

task generateClientDS(type: org.openapitools.generator.gradle.plugin.tasks.GenerateTask) {
  inputSpec = "$rootDir/specifications/client-ds.yaml".toString()
  outputDir = "$rootDir".toString()
  generatorName = 'java'
  library = 'resttemplate'
  apiPackage = 'com.example.gen.clients.clientds.api'
  modelPackage = 'com.example.gen.clients.clientds.dto'
  modelNameSuffix = 'DTO'
  configOptions = [
          hideGenerationTimestamp: 'true',
          dateLibrary: 'java8'
  ]
  typeMappings = [
          OffsetDateTime: 'java.time.LocalDateTime'
  ]
}

application.properties

spring.jackson.serialization.write-dates-as-timestamps=false

I've even added it as been but it doesn't work, any idea what is wrong?

I get the same error. After a few hours of looking found the answer here. The problem was in my API doc. Try to change it.

startDate:
type: string
format: 'yyyy-mm-dd'

I was looking for a solution to the same problem for LocalDate

For me the solution was:

typeMappings = [
        LocalDate: "String"
]

Also I found explanation of this behaviour in the tread: https://stackoverflow.com/a/75881743/8725920

> This is not a bug, but a conscious decision on the part of the developers. You said you are using the java generator with the resttemplate library. By default, the resttemplate library generates a class called RFC3339DateFormat, and a class called JavaTimeFormatter