问题

Logcat 提示’@JvmDefault’ is only supported since JVM target 1.8. Recompile with '-jvm-target 1.8’

解决

在gradle中插入以下代码

android {
   //..其他代码...

    kotlinOptions {
        jvmTarget = "1.8"
    }
}

Logcat 提示:Usage of ‘@JvmDefault’ is only allowed with -Xjvm-default option

加入:'-Xjvm-default', 'enable'

    kotlinOptions {
        jvmTarget = "1.8"
        freeCompilerArgs += [
                '-Xjvm-default', 'enable'
        ]
    }