Error: 包 com.android.annotions 不存在

我有以下课程

import com.android.annotations.NonNullByDefault;


@NonNullByDefault
public final class Log {
...
}

这是我的 build.gradle 文件(有些部分省略了)

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，没有对我的类提出警告

enter image description here

然而，当我尝试建立和运行我的应用程序，我得到这个错误从 gradle

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
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Annotations come from the support's library which are packaged in android.support.annotation.

As another option you can use @NonNull annotation which denotes that a parameter, field or method return value can never be null.
It is imported from import android.support.annotation.NonNull;

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You can find here the official javadoc of the support-annotationslibrary.

Error:(3, 31) error: package com.android.annotations does not exist

As you can see all the classes are in the same package android.support.annotation and not com.android.annotations.

Error:(7, 2) error: cannot find symbol class NonNullByDefault

Also the class NonNullByDefault doesn't exist in that package.

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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'
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In my case I had to use

import androidx.annotation...

instead of

import android.annotation...

I migrated to AndroidX and forgot to change that.

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Use implementation androidx.appcompat:appcompat:1.0.2 in gradle and then

change import android.support.annotation.Nullable; to import androidx.annotation.NonNull; in the classes imports

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To automatically fix all android to androidx issues for React Native (prerequisite npx)

Add the following two flags to true in your gradle.properties file at ProjectFolder/android/gradle.properties

android.useAndroidX=true
android.enableJetifier=true

Execute

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

In your package.json add the following to scripts

  "postinstall" : "npx jetify"

More info at https://github.com/mikehardy/jetifier

Update: This is now in-built in react-native 0.60. If you migrate to react-native 0.60 you won't need this step. - https://facebook.github.io/react-native/blog/2019/07/03/version-60#androidx-support

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if error from butterknife auto generated file then update butterknife dependency version

implementation 'com.jakewharton:butterknife:10.0.0'
annotationProcessor 'com.jakewharton:butterknife-compiler:10.0.0'
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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

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You shouldn't edit any code manually jetify should do this job for you, if you are running/building from cli using react-native you dont' need to do anything but if you are running/building Andriod studio you need to run jetify as pre-build, here is how can you automate this:

1- From the above menu go to edit configurations:

enter image description here

2- Add the bottom of the screen you will find before launch click on the plus and choose Run External Tool

enter image description here

2- Fill the following information, note that the working directory is your project root directory (not the android directory):

enter image description here

3- Make sure this run before anything else, in the end, your configuration should look something like this: enter image description here

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All you need to do is to replace 'import android.support.annotation.Nullable' in class imports to 'import androidx.annotation.Nullable;'

Thats a common practice..whenever any import giving issue...remove that import and simply press Alt+Enter on the related class..that will give you option to 'import class'..hint Enter and things will get resolved...

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I had similar issues when migrating to androidx. this issue comes due to the Old Butter Knife library dependency.

if you are using butter knife then you should use at least butter knife version 9.0.0-SNAPSHOT or above.

implementation 'com.jakewharton:butterknife:9.0.0-SNAPSHOT' annotationProcessor 'com.jakewharton:butterknife-compiler:9.0.0-SNAPSHOT'

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For me it was an old version of npm.

Run npm install npm@latest -g and then npm install

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For Ionic, try this:

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

The error comes because this app is not using androidX but these plugins solve errors.

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just install(it automatically fix)

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

then run

npx cap sync

finally

  npx react-native run-android

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