Android Studio 3.0中解决apt报错，android-apt切换为官方annotationProcessor

最近从GitHub上Fork了一个项目，用Android Studio3 打开后

报错

Error:Cannot choose between the following configurations of project :EasyAdapterLibrary:
  - debugApiElements
  - debugRuntimeElements
  - releaseApiElements
  - releaseRuntimeElements
All of them match the consumer attributes:
  - Configuration 'debugApiElements':
      - Found com.android.build.api.attributes.BuildTypeAttr 'debug' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.VariantAttr 'debug' but wasn't required.
      - Found org.gradle.api.attributes.Usage 'java-api' but wasn't required.
  - Configuration 'debugRuntimeElements':
      - Found com.android.build.api.attributes.BuildTypeAttr 'debug' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.VariantAttr 'debug' but wasn't required.
      - Found org.gradle.api.attributes.Usage 'java-runtime' but wasn't required.
  - Configuration 'releaseApiElements':
      - Found com.android.build.api.attributes.BuildTypeAttr 'release' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.VariantAttr 'release' but wasn't required.
      - Found org.gradle.api.attributes.Usage 'java-api' but wasn't required.
  - Configuration 'releaseRuntimeElements':
      - Found com.android.build.api.attributes.BuildTypeAttr 'release' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.AndroidTypeAttr 'Aar' but wasn't required.
      - Found com.android.build.gradle.internal.dependency.VariantAttr 'release' but wasn't required.
      - Found org.gradle.api.attributes.Usage 'java-runtime' but wasn't required.

原因

从Messages中并没有查看出是什么原因，但是此项目之前使用的AS2.1，并且gradle中使用了apt，所以我怀疑是Studio升级到3.0之后原来的配置方式apt与最新版本Gradle已经不兼容。

APT
APT(Annotation Processing Tool)是一种处理注释的工具,它对源代码文件进行检测找出其中的Annotation，使用Annotation进行额外的处理。
Annotation处理器在处理Annotation时可以根据源文件中的Annotation生成额外的源文件和其它的文件(文件具体内容由Annotation处理器的编写者决定),APT还会编译生成的源文件和原来的源文件，将它们一起生成class文件。

---

Android Gradle插件2.2版本发布后，Android 官方提供了annotationProcessor来代替android-apt，annotationProcessor同时支持 javac 和 jack 编译方式，而android-apt只支持 javac 方式。同时android-apt作者宣布不在维护，当然目前android-apt仍然可以正常运行，如果你没有想支持 jack 编译方式的话，可以继续使用 android-apt。Android Studio 3.0执行android-apt报错：

Android Studio 3.0执行android-apt一般会报错：

Error:android-apt plugin is incompatible with the Android Gradle plugin.  Please use 'annotationProcessor' configuration instead.

解决

android-apt切换为官方annotationProcessor的方法

1、在build.gradle修改为Android Gradle 3.0 插件

buildscript {
    repositories {
        ...
        google()
    }

-        classpath 'com.android.tools.build:gradle:2.1.0'
+        classpath 'com.android.tools.build:gradle:3.0.1'

    }
}

2、删除build.gradle里android-apt 的相关配置

项目目录下

 buildscript {
     repositories {
         maven{ url 'http://maven.aliyun.com/nexus/content/groups/public/'}
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.1.0'
-        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
+        classpath 'com.android.tools.build:gradle:3.0.1'
+       // classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
     }
 }
 

app目录下

- apply plugin: 'android-apt'
+ //apply plugin: 'android-apt'
 
 android {
     compileSdkVersion 23
     buildToolsVersion "23.0.3"

3、替换build.gradle里旧的配置为新的配置

做以下替换

• compile 改为 implementation,
• apt 改为 annotationProcessor
• testCompile 改为 androidTestImplementation

app目录下

     // Annotation
-    compile 'com.google.dagger:dagger:2.0.2'
-    apt 'com.google.dagger:dagger-compiler:2.0.2'
+//    compile 'com.google.dagger:dagger:2.0.2'
+//    apt 'com.google.dagger:dagger-compiler:2.0.2'
+    implementation 'com.google.dagger:dagger:2.9'
+    annotationProcessor 'com.google.dagger:dagger-compiler:2.9'
+

4、清理缓存并重启Android Studio 3.0

参考：
https://www.jianshu.com/p/c1666a947692
https://majing.io/posts/10000003001155