更新2020/01/17

Android Studio 4.0支持使用大量的Java 8语言API，通过使用称为desugaring的技术，而不需要为你的应用程序设置最低的API级别: https://developer.android.com/studio/preview/features#j8-desugar

The following set of APIs is supported in this release: Sequential streams (java.util.stream) A subset of java.time java.util.function Recent additions to java.util.{Map,Collection,Comparator} Optionals (java.util.Optional, java.util.OptionalInt and java.util.OptionalDouble) and some other new classes useful with the above APIs Some additions to java.util.concurrent.atomic (new methods on AtomicInteger, AtomicLong and AtomicReference) ConcurrentHashMap (with bug fixes for Android 5.0) To support these language APIs, D8 compiles a separate library DEX file that contains an implementation of the missing APIs and includes it in your app. The desugaring process rewrites your app’s code to instead use this library at runtime. To enable support for these language APIs, include the following in your module’s build.gradle file: android { defaultConfig { // Required when setting minSdkVersion to 20 or lower multiDexEnabled true } compileOptions { // Flag to enable support for the new language APIs coreLibraryDesugaringEnabled true // Sets Java compatibility to Java 8 sourceCompatibility JavaVersion.VERSION_1_8 targetCompatibility JavaVersion.VERSION_1_8 } } dependencies { coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.4' }

2017年原创文章

Android Studio 3.0开始提供对Java 8语言特性的内置支持，包括:

Lambda表达式 方法引用 类型注释(信息在编译时可用，但在运行时不可用) 重复注释 默认和静态接口方法

同样，从API级别24开始，可以使用以下Java 8 API:

java.util.stream java.util.function java.lang.FunctionalInterface java.lang.annotation.Repeatable java.lang.reflect.AnnotatedElement.getAnnotationsByType(类) java.lang.reflect.Method.isDefault ()

除此之外，try-with-resources支持扩展到所有Android API级别。

更多的Java 8特性将在未来被添加。

要开始使用受支持的Java 8语言特性，请更新Android 插件到3.0.0-alpha1(或更高版本)，并将以下内容添加到您的 模块的构建。gradle文件: android { .．. compileOptions { sourceCompatibility JavaVersion。VERSION_1_8 targetCompatibility JavaVersion。VERSION_1_8 ｝ ｝

详情请浏览: https://developer.android.com/studio/write/java8-support.html

是的。我们将很快使用Java 8 !

我们已经决定将对Java 8语言特性的支持直接添加到当前的javac和dx工具集中，并弃用Jack工具链。有了这个新方向，依赖于Java类文件格式的现有工具和插件应该可以继续工作。接下来，Java 8语言特性将被Android构建系统原生支持。我们的目标是在未来几周内将其作为Android Studio的一部分发布，我们希望尽早与大家分享这一决定。

https://android-developers.googleblog.com/2017/03/future-of-java-8-language-feature.html

更新2017/11/04 - Android Studio 3.0现在支持Java 8。Gradle-retrolambda现在不再需要了。参见https://developer.android.com/studio/write/java8-support.html

如果您正在使用gradle-retrolambda，上面的链接还包括迁移指令。原答案如下:

Android不支持Java 8。它只支持到Java 7(如果你有kitkat)，它仍然没有invokedynamic，只有新的语法sugar。

If you want to use lambdas, one of the major features of Java 8 in Android, you can use gradle-retrolamba. It's a gradle build dependency that integrates retrolambda, a tool that converts Java 8 bytecode back to Java 6/7. Basically, if you set the compiler in Android Studio to compile Java 8 bytecode, thus allowing lambdas, it'll convert it back to Java 6/7 bytecode which then in turn gets converted to dalvik bytecode. It's a hack for if you want to try out some JDK 8 features in Android in lieu of official support.

我想我应该发布一个更新的答案给那些寻找一些更当前的东西的人。

目前Android和Android Studio支持Java 8特性的一个子集。根据他们网站上的Android文档，谷歌说:

Support for Java 8 language features requires a new compiler called Jack. Jack is supported only on Android Studio 2.1 and higher. So if you want to use Java 8 language features, you need to use Android Studio 2.1 to build your app. If you already have Android Studio installed, make sure you update to the latest version by clicking Help > Check for Update (on Mac, Android Studio > Check for Updates). If you don't already have the IDE installed on your workstation, download Android Studio here. Supported Java 8 Language Features and APIs Android does not support all Java 8 language features. However, the following features are available when developing apps targeting Android 7.0 (API level 24): Default and static interface methods Lambda expressions (also available on API level 23 and lower) Repeatable annotations Method References (also available on API level 23 and lower) Type Annotations (also available on API level 23 and lower)

此外，以下Java 8语言api也可用:

Reflection and language-related APIs: java.lang.FunctionalInterface java.lang.annotation.Repeatable java.lang.reflect.Method.isDefault() and Reflection APIs associated with repeatable annotations, such as AnnotatedElement.getAnnotationsByType(Class) Utility APIs: java.util.function java.util.stream In order to use the new Java 8 language features, you need to also use the Jack toolchain. This new Android toolchain compiles Java language sources into Android-readable DEX bytecode, has its own .jack library format, and provides most toolchain features as part of a single tool: repackaging, shrinking, obfuscation and multidex. Here is a comparison of the two toolchains used to build Android DEX files: Legacy javac toolchain: javac (.java → .class) → dx (.class → .dex) New Jack toolchain: Jack (.java → .jack → .dex)

是的，你可以在Android Studio中使用Java 8语言功能，但版本必须是3.0或更高。阅读这篇文章，了解如何在android studio中使用java 8特性。

https://bijay-budhathoki.blogspot.com/2020/01/use-java-8-language-features-in-android-studio.html

更新2020/01/17

Android Studio 4.0支持使用大量的Java 8语言API，通过使用称为desugaring的技术，而不需要为你的应用程序设置最低的API级别: https://developer.android.com/studio/preview/features#j8-desugar

The following set of APIs is supported in this release: Sequential streams (java.util.stream) A subset of java.time java.util.function Recent additions to java.util.{Map,Collection,Comparator} Optionals (java.util.Optional, java.util.OptionalInt and java.util.OptionalDouble) and some other new classes useful with the above APIs Some additions to java.util.concurrent.atomic (new methods on AtomicInteger, AtomicLong and AtomicReference) ConcurrentHashMap (with bug fixes for Android 5.0) To support these language APIs, D8 compiles a separate library DEX file that contains an implementation of the missing APIs and includes it in your app. The desugaring process rewrites your app’s code to instead use this library at runtime. To enable support for these language APIs, include the following in your module’s build.gradle file: android { defaultConfig { // Required when setting minSdkVersion to 20 or lower multiDexEnabled true } compileOptions { // Flag to enable support for the new language APIs coreLibraryDesugaringEnabled true // Sets Java compatibility to Java 8 sourceCompatibility JavaVersion.VERSION_1_8 targetCompatibility JavaVersion.VERSION_1_8 } } dependencies { coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.4' }

2017年原创文章

Android Studio 3.0开始提供对Java 8语言特性的内置支持，包括:

Lambda表达式 方法引用 类型注释(信息在编译时可用，但在运行时不可用) 重复注释 默认和静态接口方法

同样，从API级别24开始，可以使用以下Java 8 API:

java.util.stream java.util.function java.lang.FunctionalInterface java.lang.annotation.Repeatable java.lang.reflect.AnnotatedElement.getAnnotationsByType(类) java.lang.reflect.Method.isDefault ()

除此之外，try-with-resources支持扩展到所有Android API级别。

更多的Java 8特性将在未来被添加。

要开始使用受支持的Java 8语言特性，请更新Android 插件到3.0.0-alpha1(或更高版本)，并将以下内容添加到您的 模块的构建。gradle文件: android { .．. compileOptions { sourceCompatibility JavaVersion。VERSION_1_8 targetCompatibility JavaVersion。VERSION_1_8 ｝ ｝

详情请浏览: https://developer.android.com/studio/write/java8-support.html