Generate Java 8 bytecode with Kotlin compiler [SPR-15183]

[spring-projects-issues]

Sébastien Deleuze opened SPR-15183 and commented

Kotlin 1.1 compiler supports generating Java 8 bytecode but generates by default Java 6 bytecode.

It can produces Java 8 bytecode with the following Gradle configuration:

compileKotlin { 
    kotlinOptions.jvmTarget = "1.8" 
} 
compileTestKotlin { 
    kotlinOptions.jvmTarget = "1.8" 
} 

It works flawlessly with Gradle but generate some errors in IDEA with default configuration. This should be fixed by KT-15819 so I prefer to wait a new Kotlin 1.1 build that fixes this issue before fixing this issue.

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Issue Links:

• Upgrade to Kotlin 1.1-beta [SPR-15100] #19667 Upgrade to Kotlin 1.1-beta

Referenced from: commits 692e432

[spring-projects-issues]

Sébastien Deleuze commented

With latest Kotlin Beta 2, the latest blocker for that is to be able to generate Java 8 bytecode with Kotlin Script, Ilya Chernikov from Kotlin team is aware of this issue and will try to provide a fix before 1.1 GA.