错误：包com.android.annotations不存在

Question

我有以下课程

import com.android.annotations.NonNullByDefault;

@NonNullByDefault
public final class Log {
    ...
}

这是我的build.gradle文件（省略了一些部分）

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion '24.0.1'

    defaultConfig {
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 2
        versionName "0.2"
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }

}

dependencies {    
    compile 'com.android.support:appcompat-v7:25.0.0'
    compile 'com.android.support:support-annotations:25.0.0'
    compile 'com.android.support:design:25.0.0'
}

在Android Studio中，我的课程没有警告

但是，当我尝试构建和运行我的应用程序时，我从gradle中得到了此错误

Information:Gradle tasks [:app:clean, :app:generateDebugSources, :app:generateDebugAndroidTestSources, :app:mockableAndroidJar, :app:prepareDebugUnitTestDependencies, :app:assembleDebug]
Warning:[options] bootstrap class path not set in conjunction with -source 1.7
/home/puter/git-repos/TaskManager3/app/src/main/java/com/treemetrics/taskmanager3/util/Log.java
Error:(3, 31) error: package com.android.annotations does not exist
Error:(7, 2) error: cannot find symbol class NonNullByDefault
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.
Information:BUILD FAILED
Information:Total time: 21.021 secs
Information:3 errors
Information:1 warning
Information:See complete output in console

Answer 1

要自动修复React Native的所有android至androidx问题，（前提条件npx）

将以下两个标记添加到位于ProjectFolder / android / gradle.properties的gradle.properties文件中的true

android.useAndroidX=true
android.enableJetifier=true

执行

npm install --save-dev jetifier
npx jetify
npx react-native run-android

在package.json中，将以下内容添加到脚本中

  "postinstall" : "npx jetify"

更多信息请参见https://github.com/mikehardy/jetifier

更新： 现在内置于本机0.60中。如果您迁移到本机0.60，则不需要此步骤。- https://facebook.github.io/react-native/blog/2019/07/03/version-60#androidx-support

Answer 2

androidx.appcompat:appcompat:1.0.2在gradle中使用实现，然后

更改import android.support.annotation.Nullable; 为import androidx.annotation.NonNull;类导入

Answer 3

I had similar issues when migrating to androidx.

If by adding the below two lines to gradle.properties did not solve the issue

android.useAndroidX=true
android.enableJetifier=true

Then try

1. With Android Studio 3.2 and higher, you can migrate an existing project to AndroidX by selecting Refactor > Migrate to AndroidX from the menu bar (developer.android.com)

If you still run into issues with migration then manually try to replace the libraries which are causing the issue.

For example

If you have an issue with android.support.annotation.NonNull change it to androidx.annotation.NonNull as indicated in the below class mappings table.

Class Mappings

Maven Artifact Mappings

Answer 4

就我而言，我不得不使用

import androidx.annotation...

代替

import android.annotation...

我迁移到 AndroidX 并忘记更改它。

Answer 5

Open gradle.properties and use following code:

android.useAndroidX=false
android.enableJetifier=false

or U can use these dependencies too:

implementation 'androidx.appcompat:appcompat:1.0.2'
 implementation 'androidx.annotation:annotation:1.0.2'

Answer 6

对于 Ionic，试试这个：

ionic cordova plugin add cordova-plugin-androidx
ionic cordova plugin add cordova-plugin-androidx-adapter

出现错误是因为该应用程序未使用 androidX，但这些插件解决了错误。

Answer 7

只需安装（它会自动修复）

npm install --save-dev jetifier <--------avoid if aleardy installed start from below lines
npx jetify

然后运行

npx cap sync

最后

  npx react-native run-android

  

Answer 8

注释来自support's library打包在android.support.annotation.

作为另一个选项，您可以使用@NonNull注释来表示参数、字段或方法返回值永远不能为空。
它是从进口的import android.support.annotation.NonNull;