在androidstudiox3.0上依赖了butterknife7.0.1的版本，运行时出现了如下错误

Error:Execution failed for task ‘:app:javaPreCompileDebug’.

> Annotation processors must be explicitly declared now.  The following dependencies on the compile classpath are found to contain annotation processor.  Please add them to the annotationProcessor configuration.

– butterknife-7.0.1.jar (com.jakewharton:butterknife:7.0.1)

Alternatively, set android.defaultConfig.javaCompileOptions.annotationProcessorOptions.includeCompileClasspath = true to continue with previous behavior.  Note that this option is deprecated and will be removed in the future.

See https://developer.android.com/r/tools/annotation-processor-error-message.html for more details.

这种的解决方案是：

在你module的build.gradle文件中添加如下代码即可

代码如下：

javaCompileOptions{

annotationProcessorOptions{

includeCompileClasspath=true

}

}