I have a Java library https://github.com/skycavemc/skycavelib which I want to use in a Kotlin project. This is the build.gradle where I have the library as dependency:

import java.util.Properties
import java.io.FileInputStream

plugins {
    kotlin("jvm") version "1.7.10"
}

group = "de.skycave"
version = "1.0.0"

val localProperties = Properties()
localProperties.load(FileInputStream(rootProject.file("local.properties")))

repositories {
    mavenCentral()
    maven { url = uri("https://repo.papermc.io/repository/maven-public/") }
    maven { url = uri("https://jitpack.io") }
    maven {
        url = uri("https://maven.pkg.github.com/skycavemc/skycavelib")
        credentials {
            username = localProperties.getProperty("gpr.user")
            password = localProperties.getProperty("gpr.key")
        }
    }
}

dependencies {
    implementation(kotlin("stdlib"))
    compileOnly("io.papermc.paper:paper-api:1.19.2-R0.1-SNAPSHOT")
    implementation("de.skycave:skycavelib:1.0.2")
}

java {
    toolchain.languageVersion.set(JavaLanguageVersion.of(17))
}

I also made sure I have a file named local.properties in my project where I set gpr.user and gpr.key correctly. The authentication works and the library is downloaded and indexed. IntelliJ also shows the library under "External Libraries".

When I try to use a class from that library, IntelliJ's autocompletion suggests the correct import. But after importing it, IntelliJ says "Unresolved reference" in the line of the import and the line where I use that class.

However, the gradle build still succeeds. Also, I only experience this issue when I import something from that library in a Kotlin class. In a Java class, IntelliJ can resolve the reference. This problem does not only happen in one specific project, but in all projects where I try to import something from that library, which means it's probably not an issue with the project configuration. The other Java library I use (paper-api) works fine when importing in both Kotlin and Java files. Invalidating caches and reloading all gradle projects has not solved the issue.

I suppose there is something misconfigured in my library https://github.com/skycavemc/skycavelib. Does someone have an idea what could have went wrong there? This is my build.gradle for the library I am trying to import from:

plugins {
    id 'java'
    id 'org.jetbrains.kotlin.jvm' version '1.7.10'
    id 'com.github.johnrengelman.shadow' version '7.1.2'
    id 'maven-publish'
}

group = 'de.skycave'
version = '1.0.2'

def localProperties = new Properties()
localProperties.load(new FileInputStream(rootProject.file("local.properties")))

repositories {
    mavenCentral()
    maven {
        name = 'papermc-repo'
        url = 'https://repo.papermc.io/repository/maven-public/'
    }
    maven {
        name = 'sonatype'
        url = 'https://oss.sonatype.org/content/groups/public/'
    }
    maven {
        name = 'jitpack'
        url = 'https://jitpack.io'
    }
}

dependencies {
    implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.7.10'
    compileOnly 'io.papermc.paper:paper-api:1.19.2-R0.1-SNAPSHOT'
    implementation 'org.mongodb:mongodb-driver-sync:4.7.1'
    implementation 'com.google.code.gson:gson:2.9.1'
    implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.12.0'
    implementation group: 'commons-io', name: 'commons-io', version: '2.11.0'
    implementation 'com.github.heuerleon:mcguiapi:v1.3.5'
}

def targetJavaVersion = 17
java {
    def javaVersion = JavaVersion.toVersion(targetJavaVersion)
    sourceCompatibility = javaVersion
    targetCompatibility = javaVersion
    if (JavaVersion.current() < javaVersion) {
        toolchain.languageVersion = JavaLanguageVersion.of(targetJavaVersion)
    }
    manifest {
        attributes 'Main-Class': "de.skycave.skycavelib.SkyCaveLib"
    }
}

tasks.withType(JavaCompile).configureEach {
    if (targetJavaVersion >= 10 || JavaVersion.current().isJava10Compatible()) {
        //noinspection GroovyAssignabilityCheck, GroovyAccessibility
        options.release = targetJavaVersion
    }
}

processResources {
    def props = [version: version]
    inputs.properties props
    filteringCharset 'UTF-8'
    filesMatching('plugin.yml') {
        expand props
    }
}

build {
    dependsOn(shadowJar)
}

shadowJar {
    archiveFileName.set("${project.name}-${project.version}.jar")
}

publishing {
    repositories {
        maven {
            name = "GitHubPackages"
            url = "https://maven.pkg.github.com/skycavemc/skycavelib"
            credentials {
                username = localProperties.getProperty("gpr.user") ?: System.getenv("GITHUB_ACTOR")
                password = localProperties.getProperty("gpr.token") ?: System.getenv("ACCESS_TOKEN")
            }
        }
    }
    publications {
        library(MavenPublication) {
            from components.java
        }
    }
}

CodePudding user response：

Solution

I did some more research and found a hint that shadowed jars might not work well. I removed this part

build {
    dependsOn(shadowJar)
}

from the build.gradle of my library and published it to the package repository. Everything works fine since then, seems like that was the issue.