kotlin springboot jackson google gson. Jacshon still used-CodePudding

I know several issues have been raised on this topic, but why Jackson is still used to serialize and deserialize JSON whereas I've excluded it from everywhere : in the springboot application, in build.gradle.kts and set the preferred Json serializer in application.properties

When I "crash" this HTTP request for test driven purpose, I can see that the crash is due to jackson converter

class IronMaidenSourceApi {
    companion object {
        fun fetchIronMaidenSource(): ResponseEntity<DTOIronMaidenAPi> {
            val uri = "http://localhost:3004/ironmaiden"
            return RestTemplate().getForEntity(uri, DTOIronMaidenAPi::class.java) // <-- JACKSON still used here
        }
    }
}

error is :

at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType

So how the hell can I totally exclude Jackson ?

Not in dependencies

dependencies {
    implementation("org.springframework.boot:spring-boot-starter-data-jpa")
    implementation("org.springframework.boot:spring-boot-starter-web")
    implementation("org.jetbrains.kotlin:kotlin-reflect")
    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
    developmentOnly("org.springframework.boot:spring-boot-devtools")
    runtimeOnly("org.postgresql:postgresql")
    testImplementation("org.springframework.boot:spring-boot-starter-test")
    implementation ("com.google.code.gson:gson:2.9.0")
}

preferred is set to GSon in application.properties

spring.jpa.open-in-view=false
server.port=7070
spring.http.converters.preferred-json-mapper=gson

exclude in main application

@SpringBootApplication(exclude = [JacksonAutoConfiguration::class])

CodePudding user response：

You need to exclude the transitive dependency like this:

dependencies {
implementation('commons-beanutils:commons-beanutils:1.9.4') {
    exclude group: 'commons-collections', module: 'commons-collections'
}

Look at your dependency tree to see which dependencies are pulling it in and exclude it from each.