ClassCastException when using reloading with kotlinx.dnq

[gzoritchak]

Ktor 1.2.2, Netty
with OAuth, CallLogging, StatusPages, Sessions, ContentNegotiation

I use the Xodus database with Kotlinx.dnq.

Without reloading, it works fine. But trying to add reloading fails during startup, while Xodus.dnq is trying to access to the companion object of an entity.

Caused by: java.lang.ClassCastException: kotlin.reflect.jvm.internal.KClassImpl cannot be cast to kotlin.reflect.jvm.internal.KClassImpl
	at kotlin.reflect.full.KClasses.getCompanionObject(KClasses.kt:52)
	at kotlinx.dnq.util.ReflectionUtilKt.getEnclosingEntityClass(ReflectionUtil.kt:47)
	at kotlinx.dnq.util.ReflectionUtilKt.getParent(ReflectionUtil.kt:60)
	at kotlinx.dnq.XdModel.registerNode(XdModel.kt:87)
	at kotlinx.dnq.XdModel.registerNodes(XdModel.kt:120)

[kam1sh]

Similar issue: Java 1.8 Ktor 1.3.2 with the next gradle dependencies:

$ cat gradle.properties 
javaVersion=1.8
systemProp.kotlinVersion=1.3.72
serializationVersion=0.20.0
kotlin.code.style=official
kotlin.incremental=true
org.gradle.caching=true

# Dependencies

## backend
ktorVersion=1.3.2
hikariVersion=3.2.0
commonsCodecVersion=1.10
jdbcNamedParametersVersion=1.1
logbackVersion=1.2.3
coroutinesVersion=1.3.7
junitVersion=5.6.2
jacksonVersion=2.10.1
koinVersion=2.1.6
hibernateVersion=5.4.15.Final

$ cat build.gradle.kts
<...>
                implementation(kotlin("stdlib-jdk8"))
                implementation(kotlin("reflect"))
                //////////
                // KTOR //
                //////////
                implementation("io.ktor:ktor-server-netty:$ktorVersion")
                implementation("io.ktor:ktor-auth:$ktorVersion")
                implementation("io.ktor:ktor-pebble:$ktorVersion")
                implementation("io.ktor:ktor-client-cio:$ktorVersion")
                implementation("io.ktor:ktor-locations:$ktorVersion")

                /////////////
                // LOGGING //
                /////////////
                implementation("org.slf4j:slf4j-api:1.7.30")
                implementation("ch.qos.logback:logback-classic:$logbackVersion")

                //////////////
                // DATABASE //
                //////////////
                implementation("mysql:mysql-connector-java:8.0.20")
                implementation("org.hibernate:hibernate-core:$hibernateVersion")
                implementation("org.hibernate:hibernate-entitymanager:$hibernateVersion")
                implementation("org.hibernate:hibernate-hikaricp:$hibernateVersion")
                implementation("com.zaxxer:HikariCP:$hikariVersion")
                implementation("org.flywaydb:flyway-core:6.2.0")

                /////////////
                // JACKSON //
                /////////////
                implementation("com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:$jacksonVersion")
                implementation("com.fasterxml.jackson.core:jackson-databind:$jacksonVersion")
                implementation("com.fasterxml.jackson.module:jackson-module-kotlin:$jacksonVersion")
                implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:$jacksonVersion")

                ////////
                // DI //
                ////////
                implementation("org.koin:koin-core:$koinVersion")
                implementation("org.koin:koin-ktor:$koinVersion")
                implementation("org.koin:koin-logger-slf4j:$koinVersion")
                //////////
                // MISC //
                //////////
                implementation("com.github.ajalt:clikt:2.3.0")
                implementation("commons-codec:commons-codec:$commonsCodecVersion")
                implementation("com.axiomalaska:jdbc-named-parameters:$jdbcNamedParametersVersion")
                implementation("com.github.andrewoma.kwery:core:$kweryVersion")
                implementation("de.mkammerer:argon2-jvm:2.7")
<...>

Exception occurs while launching application:

Exception in thread "main" java.lang.reflect.InvocationTargetException
        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 kotlin.reflect.jvm.internal.calls.CallerImpl$Method.callMethod(CallerImpl.kt:97)
        at kotlin.reflect.jvm.internal.calls.CallerImpl$Method$Static.call(CallerImpl.kt:106)
        at kotlin.reflect.jvm.internal.KCallableImpl.call(KCallableImpl.kt:106)
        at kotlin.reflect.jvm.internal.KCallableImpl.callDefaultMethod$kotlin_reflection(KCallableImpl.kt:152)
        at kotlin.reflect.jvm.internal.KCallableImpl.callBy(KCallableImpl.kt:110)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.callFunctionWithInjection(ApplicationEngineEnvironmentReloading.kt:384)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.executeModuleFunction(ApplicationEngineEnvironmentReloading.kt:330)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.access$executeModuleFunction(ApplicationEngineEnvironmentReloading.kt:33)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1$$special$$inlined$forEach$lambda$1.invoke(ApplicationEngineEnvironmentReloading.kt:275)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1$$special$$inlined$forEach$lambda$1.invoke(ApplicationEngineEnvironmentReloading.kt:33)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.avoidingDoubleStartupFor(ApplicationEngineEnvironmentReloading.kt:310)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.access$avoidingDoubleStartupFor(ApplicationEngineEnvironmentReloading.kt:33)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1.invoke(ApplicationEngineEnvironmentReloading.kt:274)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1.invoke(ApplicationEngineEnvironmentReloading.kt:33)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.avoidingDoubleStartup(ApplicationEngineEnvironmentReloading.kt:290)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.instantiateAndConfigureApplication(ApplicationEngineEnvironmentReloading.kt:272)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.createApplication(ApplicationEngineEnvironmentReloading.kt:125)
        at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.start(ApplicationEngineEnvironmentReloading.kt:245)
        at io.ktor.server.netty.NettyApplicationEngine.start(NettyApplicationEngine.kt:126)
        at org.cec.platform.commands.Serve.run(Serve.kt:22)
        at com.github.ajalt.clikt.parsers.Parser.parse(Parser.kt:139)
        at com.github.ajalt.clikt.parsers.Parser.parse(Parser.kt:14)
        at com.github.ajalt.clikt.core.CliktCommand.parse(CliktCommand.kt:215)
        at com.github.ajalt.clikt.core.CliktCommand.parse$default(CliktCommand.kt:212)
        at com.github.ajalt.clikt.core.CliktCommand.main(CliktCommand.kt:230)
        at com.github.ajalt.clikt.core.CliktCommand.main(CliktCommand.kt:253)
        at org.cec.platform.AppKt.main(App.kt:223)
Caused by: java.lang.ClassCastException: org.cec.platform.App cannot be cast to org.cec.platform.App
        at org.cec.platform.AppKt.main(App.kt:118)
        ... 31 more

It's not critical, but it would be nice if someone will fix that =)

[oleg-larshin]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.

[Stexxe]

Could you please share a code snippet to reproduce this problem if it's still relevant?