添加依赖报错：Annotation processors must be explicitly declared now.

前言

从GitHub上克隆了一个项目，在依赖下有个ButterKnife的错误：

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.

解决办法一：

在app的build中添加下面的代码（没有试过，可能会失效）

	defaultConfig {
        ...
       	 javaCompileOptions {
         	   annotationProcessorOptions {
             	   includeCompileClasspath true
          	  }
      	  }
   	 }

解决办法二：

修改依赖：

	provided 'com.jakewharton:butterknife:7.0.1'
	annotationProcessor 'com.jakewharton:butterknife:7.0.1'

但是provided已经被替换为compileOnly，所以需要改为：

	compileOnly 'com.jakewharton:butterknife:7.0.1'
    annotationProcessor 'com.jakewharton:butterknife:7.0.1'

解决办法三：

我在试了第二种方法后，仍出现错误build时可以通过，但在手机上运行时程序闪退，存在以下错误：

java.lang.NoClassDefFoundError: Failed resolution of: Lbutterknife/ButterKnife;
                      at com.kevin.imagecrop.activity.basic.BaseActivity.onCreate(BaseActivity.java:39)
                      at android.app.Activity.performCreate(Activity.java:5990)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
                      at android.app.ActivityThread.access$800(ActivityThread.java:151)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:135)
                      at android.app.ActivityThread.main(ActivityThread.java:5254)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:372)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
                   Caused by: java.lang.ClassNotFoundException: Didn't find class "butterknife.ButterKnife" on path: DexPathList[[zip file "/data/app/com.kevin.imagecrop-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
                      at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
                      at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
                      at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
                      at com.kevin.imagecrop.activity.basic.BaseActivity.onCreate(BaseActivity.java:39) 
                      at android.app.Activity.performCreate(Activity.java:5990) 
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278) 
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
                      at android.app.ActivityThread.access$800(ActivityThread.java:151) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:135) 
                      at android.app.ActivityThread.main(ActivityThread.java:5254) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
                  	Suppressed: java.lang.ClassNotFoundException: butterknife.ButterKnife
                      at java.lang.Class.classForName(Native Method)
                      at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
                      at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
                      at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
                      		... 15 more
                   Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

解决办法：依赖最终修改为

	implementation 'com.jakewharton:butterknife:7.0.1'
    annotationProcessor 'com.jakewharton:butterknife:7.0.1'