Android studio add Java 8 config get error "Could not get unknown property"

Question

build.gradle config：

apply plugin: 'com.android.application'
apply plugin: 'realm-android'
//apply plugin: 'android-apt'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.way.event"
        minSdkVersion 21
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        jackOptions {
            enabled true
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.0.0'
    compile 'com.android.support:design:25.0.0'
    compile 'com.android.support:support-v4:25.0.0'
    testCompile 'junit:junit:4.12'
}

It didn't support Java8：

Error:Could not get unknown property 'classpath' for task ':app:transformJackWithJackForDebug' of type com.android.build.gradle.internal.pipeline.TransformTask.

Does it has anything to do with the Realm ? how to resolve it?

Yes. It's a realm problem. https://github.com/realm/realm-java/issues/3038 — OneCricketeer, Dec 23 '16 at 02:31
Possible duplicate of [How to use Realm database with Java 8 features](http://stackoverflow.com/questions/38704069/how-to-use-realm-database-with-java-8-features) — EpicPandaForce, Dec 23 '16 at 09:46

score 5 · Answer 1 · answered Dec 23 '16 at 09:51

Well, you can still use Retrolambda instead of Jack, nobody is stopping you from using lambdas.

buildscript {
    repositories {
        mavenCentral()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.0'
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
        classpath "io.realm:realm-gradle-plugin:1.2.0"
        classpath 'me.tatarka:gradle-retrolambda:3.2.5'
    }
}

and

apply plugin: 'com.android.application'
apply plugin: 'com.neenbedankt.android-apt'
apply plugin: 'me.tatarka.retrolambda'
apply plugin: 'realm-android'

android {
    compileSdkVersion xx
    buildToolsVersion "xx"

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

works just fine for Java 8 language features (lambdas, method references, try-with-resources).

score 1 · Answer 2 · answered Dec 10 '20 at 07:14

1

remove the previously dependent lambda library, because after 3.0, the AS itself supports the lambda.

Apply plugin: 'me.tatarka.retrolambda' //Remove this sentence

answered Dec 10 '20 at 07:14

abbasalim

3,118
2
23
45

Waylan Punch · Answer 3 · 2016-12-26T08:56:10.617

0

Thanks to @cricket_007

Support Jack compiler #3038

GitHub User @kirsting , he told me he can provide a solution to this problem. Check his comment on this issue below:

Java 1.8 and Android not working #2630

edited Dec 26 '16 at 08:56

answered Dec 23 '16 at 06:31

Waylan Punch

239
4
17

Android studio add Java 8 config get error "Could not get unknown property"

3 Answers3