The horologist sample app has already switched to compileOptions `JavaVersion.VERSION_11` , I am sti...

# compose-wear

[Yingding Wang]

The horologist sample app has already switched to compileOptions JavaVersion.VERSION_11 , I am still using JavaVersion.VERSION_1_8 for most of my wear os apps. Is there any benefits or concerns i shall consider before switching?

[florent]

It just compile faster you can even switch to java 17 that's fine to use and you get a 10% compile time improvement with 17

[Yingding Wang]

Will the binary still work on wear os 2?

[florent]

If you have the desujar lib it shouldn't be any problems

[Yingding Wang]

Thats great, thanks.

[Yingding Wang]

The build process is really faster after switching to JavaVersion.VERSION_11, I got a warning

> Task :wear:kaptGenerateStubsDebugKotlin
'compileDebugJavaWithJavac' task (current target is 11) and 'kaptGenerateStubsDebugKotlin' task (current target is 1.8) jvm target compatibility should be set to the same Java version.

I am not sure where is this kaptGenerateStubsDebugKotlin task coming from.

[florent]

You need to set kotlinOptions { jvmTarget = '11' }

[Yingding Wang]

I did that already.

[Yingding Wang]

The reason is that the kotlinOptions is deprecated in groovy for gradle 7.5. The new syntax is:

kotlin {
    jvmToolchain(11)
}

https://stackoverflow.com/questions/69079963/how-to-set-compilejava-task-11-and-compilekotlin-task-1-8-jvm-target-com/75395975#75395975

[florent]

I am talking about the kotlinOptions in android {}

[Yingding Wang]

Sure, but the android { kotlinOptions { jvmTarget = "11"} } doesn’t work for me with gradle 7.5 and kotlin 1.8.10 for some reason. I have to use the new syntax android { kotlin { jvmToolchain(11) } } . And you are right, the kaptGenerateStudsDebugKotlin task warning indicate that the kotlinOptions for jvmTarget is not set properly.