在更新到Android Studio 3.0并创建一个新项目后,我注意到在构建中。gradle有一种新方法来添加新的依赖项,而不是compile,而是implementation,而不是testCompile,而是testimplemimplementation。
例子:
implementation 'com.android.support:appcompat-v7:25.0.0'
testImplementation 'junit:junit:4.12'
而不是
compile 'com.android.support:appcompat-v7:25.0.0'
testCompile 'junit:junit:4.12'
它们之间的区别是什么,我应该用什么?
博士tl;
只是替换:
使用实现(如果你不需要传递性)或API(如果你需要传递性)编译
使用testimplemimplementation进行testCompile
使用debugImplementation进行debugCompile
androidTestCompile与androidTestImplementation
compileOnly仍然有效。它是在3.0中添加的,用于替换提供的和不编译的。(当Gradle没有为该用例提供配置名称时,就引入了该用例,并以Maven提供的作用域命名。)
这是谷歌在IO17大会上宣布的Android Gradle插件3.0的突破性变化之一。
compile配置现在已弃用,应该由实现或api取代
来自Gradle文档:
dependencies {
api("commons-httpclient:commons-httpclient:3.1")
implementation("org.apache.commons:commons-lang3:3.5")
}
Dependencies appearing in the api configurations will be
transitively exposed to consumers of the library, and as such will
appear on the compile classpath of consumers.
Dependencies found in the implementation configuration will, on the
other hand, not be exposed to consumers, and therefore not leak into
the consumers' compile classpath. This comes with several benefits:
dependencies do not leak into the compile classpath of consumers anymore, so you will never accidentally depend on a transitive
dependency
faster compilation thanks to reduced classpath size
less recompilations when implementation dependencies change: consumers would not need to be recompiled
cleaner publishing: when used in conjunction with the new maven-publish plugin, Java libraries produce POM files that
distinguish exactly between what is required to compile against the
library and what is required to use the library at runtime (in other
words, don't mix what is needed to compile the library itself and what
is needed to compile against the library).
The compile configuration still exists, but should not be used as it will not offer the guarantees that the api and implementation configurations provide.
注意:如果你只在你的app模块中使用一个库——通常情况下——你不会注意到任何区别。
只有当您有一个相互依赖的模块的复杂项目,或者您正在创建一个库时,您才会看到区别。