集成butterknife出现 Error:Unable to find method 'com.android.build.gradle.api.BaseVariant.getOutputs()

错误为： Error:Unable to find method 'com.android.build.gradle.api.BaseVariant.getOutputs()Ljava/util/List;'.

Possible causes for this unexpected error include:<ul><li>Gradle's dependency cache may be corrupt (this sometimes occurs after a network connection timeout.)

<a href="syncProject" target="_blank" rel="external nofollow" >Re-download dependencies and sync project (requires network)</a></li><li>The state of a Gradle build process (daemon) may be corrupt. Stopping all Gradle daemons may solve this problem.

<a href="stopGradleDaemons" target="_blank" rel="external nofollow" >Stop Gradle build processes (requires restart)</a></li><li>Your project may be using a third-party plugin which is not compatible with the other plugins in the project or the version of Gradle requested by the project.</li></ul>In the case of corrupt Gradle processes, you can also try closing the IDE and then killing all Java processes.

发现其实是Android Studio3.0与butterknife的冲突，github上面已经有了这个问题issue

解决办法：将butterknife的版本降到8.4.0就可以了