Kotlin always tells me KotlinReflectionNotSupportedError - gradle

Question

I've just started converting to Kotlin from Java. I have a question: when I'm reflecting something like:
XXClass::class.java
or anything else. They don't work in JAR, but work fine from IDE.
I'm using gradle :module:build or gradle :module:jar to generate the JAR file. After generating, it always tells me KotlinReflectionNotSupportedError: Kotlin reflection implementation is not found at runtime. Make sure you have kotlin-reflect.jar in the classpath. But I've already added them into dependencies, and they work fine in IDE.
These are parts of my gradle files (Please notice that this is a kotlin application module, not an Android module):
// (Module level)
apply plugin: 'kotlin'
sourceCompatibility = 1.8
dependencies {
// Others...
// I've already added reflect and stdlib
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
}
jar {
manifest {
// ...
}
// To include dependencies to build a fat jar
from {
configurations.compile.collect {
it.isDirectory() ? it : zipTree(it)
}
}
}
// Include reflect and stdlib
compileKotlin {
kotlinOptions {
jvmTarget = "1.8"
javaParameters = true
noReflect = false
noStdlib = false
}
}
// (Project level)
buildscript {
ext.kotlin_version = '1.3.11'
repositories {
// ...
}
dependencies {
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
Could anyone give me a hand? Thanks a lot.

Answer 1

The issue is in this block of script
configurations.compile.collect {
it.isDirectory() ? it : zipTree(it)
}
You've included the dependencies ( kotlin-reflect ) using implementation configuration, but collecting the dependencies from compile configuration. If you changed your config from implementation to compile, this block will work. Since compile is deprecated, you can try something like this to collect your dependencies to your jar
compileJava.classpath.collect {
it.isDirectory() ? it : zipTree(it)
}
see this answer