Android Studio throws build error in Kotlin project which calls static method in java interface

Question

I have a Kotlin project in Android Studio. I am calling a static method in Java interface from the Kotlin code. The build fails with the error,

Calls to static methods in Java interfaces are prohibited in JVM target 1.6. Recompile with '-jvm-target 1.8'

I have the following in my build.gradle,

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

I have also changed the Target JVM version to 1.8 in Kotlin compiler settings. Still, the build throws the error. Also tried Invalidating cache and restarting.

Android Studio version: 3.0.1

in android studio try **File** > **Invalidate Cashes & Restart...** — y.allam, Feb 23 '18 at 17:25

score 11 · Answer 1 · answered Apr 11 '18 at 09:56

Proper way to set Kotlin compile options in android gradle. Make these changes to your app level Build.gradle

Change

implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"

to

implementation "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"

Then write this task

tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
    sourceCompatibility = JavaVersion.VERSION_1_8
    targetCompatibility = JavaVersion.VERSION_1_8

    kotlinOptions {
        jvmTarget = '1.8'
        apiVersion = '1.1'
        languageVersion = '1.1'
    }
}

just below(not necessarily)

repositories {
    mavenCentral()
}

For details, refer here

score 5 · Answer 2 · answered Feb 23 '18 at 17:41

5

The compileOptions section in build.gradle affects the Java compiler, not the Kotlin compiler. To set the target JVM version for the Kotlin compiler, use the following block:

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

See the documentation for more information.

answered Feb 23 '18 at 17:41

yole

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I added the following code to my root build.grade file, Still getting the same error. `plugins { id "org.jetbrains.kotlin.jvm" version "1.2.21" } compileKotlin { kotlinOptions.jvmTarget = "1.8" } compileTestKotlin { kotlinOptions.jvmTarget = "1.8" }` – Raj Feb 24 '18 at 01:50

score 0 · Answer 3 · answered Aug 21 '19 at 11:10

I had the same problem because I had a folder for the integration tests different than the unit test folder. So the build.gradle needs more configuration:

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
} 
//added this
compileIntegrationTestKotlin {
  kotlinOptions.jvmTarget = "1.8"
}

score 0 · Answer 4 · answered Apr 15 '20 at 12:58

I am able to resolve this by adding below block as my build.gradle is not in dsl. To set the target JVM version for the Kotlin compiler, use the following block:

tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
    kotlinOptions {
        jvmTarget = "1.8"
    }
}

Android Studio throws build error in Kotlin project which calls static method in java interface

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