flutter - Flutter 应用程序构建上的任务 ':sms:verifyReleaseResources' 和线程 "main"中的异常 java.lang.NullPointerException 执行失败

Question

嘿，我在构建我的应用程序时遇到了一个问题。
只有当我尝试将 apk 构建为发行版时才会出现错误我可以调试它并且我可以将应用程序构建为调试我尝试将 compileSDKVersion 更改为 28 并将 targetSdkVersion 也更改为 28

这是我收到的回复 flutter build apk --release司令部。

flutter build apk

You are building a fat APK that includes binaries for android-arm, android-arm64, android-x64.
If you are deploying the app to the Play Store, it's recommended to use app bundles or split the APK to reduce the APK size.
    To generate an app bundle, run:
        flutter build appbundle --target-platform android-arm,android-arm64,android-x64
        Learn more on: https://developer.android.com/guide/app-bundle
    To split the APKs per ABI, run:
        flutter build apk --target-platform android-arm,android-arm64,android-x64 --split-per-abi
        Learn more on:  https://developer.android.com/studio/build/configure-apk-splits#configure-abi-split
Running Gradle task 'assembleRelease'...                                
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:15: error: package android.support.annotation does not exist
import android.support.annotation.VisibleForTesting;
                                 ^
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:16: error: cannot find symbol
import android.support.v4.app.ActivityCompat;
                             ^
  symbol:   class ActivityCompat
  location: package android.support.v4.app
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:17: error: package android.support.v4.content does not exist
import android.support.v4.content.FileProvider;
                                 ^
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerFileProvider.java:3: error: package android.support.v4.content does not exist
import android.support.v4.content.FileProvider;
                                 ^
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerFileProvider.java:10: error: cannot find symbol
public class ImagePickerFileProvider extends FileProvider {}
                                             ^
  symbol: class FileProvider
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerPlugin.java:8: error: package android.support.annotation does not exist
import android.support.annotation.VisibleForTesting;
                                 ^
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:68: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_CODE_CHOOSE_IMAGE_FROM_GALLERY = 2342;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:69: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_CODE_TAKE_IMAGE_WITH_CAMERA = 2343;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:70: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_EXTERNAL_IMAGE_STORAGE_PERMISSION = 2344;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:71: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_CAMERA_IMAGE_PERMISSION = 2345;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:72: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_CODE_CHOOSE_VIDEO_FROM_GALLERY = 2352;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:73: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_CODE_TAKE_VIDEO_WITH_CAMERA = 2353;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:74: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_EXTERNAL_VIDEO_STORAGE_PERMISSION = 2354;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:75: error: cannot find symbol
  @VisibleForTesting static final int REQUEST_CAMERA_VIDEO_PERMISSION = 2355;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:77: error: cannot find symbol
  @VisibleForTesting final String fileProviderName;
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:164: error: cannot find symbol
  @VisibleForTesting
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerDelegate
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerPlugin.java:40: error: cannot find symbol
  @VisibleForTesting
   ^
  symbol:   class VisibleForTesting
  location: class ImagePickerPlugin
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:122: error: cannot find symbol
            return ActivityCompat.checkSelfPermission(activity, permissionName)
                   ^
  symbol: variable ActivityCompat
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:128: error: cannot find symbol
            ActivityCompat.requestPermissions(activity, new String[] {permissionName}, requestCode);
            ^
  symbol: variable ActivityCompat
C:\Users\iAbdou\AppData\Roaming\Pub\Cache\hosted\pub.dartlang.org\image_picker-0.4.12+1\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java:140: error: cannot find symbol
            return FileProvider.getUriForFile(activity, fileProviderName, file);
                   ^
  symbol: variable FileProvider
20 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':image_picker:compileReleaseJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 3m 10s
Running Gradle task 'assembleRelease'...                        
Running Gradle task 'assembleRelease'... Done                     193.4s (!)
The built failed likely due to AndroidX incompatibilities in a plugin. The tool is about to try using Jetfier to solve the
incompatibility.
Building plugin flutter_plugin_android_lifecycle...
Running Gradle task 'assembleAarRelease'...
Running Gradle task 'assembleAarRelease'... Done                    0.6s

Exception in thread "main" java.lang.NullPointerException
        at org.gradle.wrapper.BootstrapMainStarter.findLauncherJar(BootstrapMainStarter.java:34)
        at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:25)
        at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:129)
        at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)


The plugin flutter_plugin_android_lifecycle could not be built due to the issue above.

我的 Flutter Doctor 回复。

flutter doctor

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, v1.12.13, on Microsoft Windows [Version 10.0.18362.720], locale en-US)

[√] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[√] Android Studio (version 3.4)
[!] IntelliJ IDEA Ultimate Edition (version 2019.1)
    X Flutter plugin not installed; this adds Flutter specific functionality.
    X Dart plugin not installed; this adds Dart specific functionality.
[√] VS Code (version 1.43.1)
[!] Connected device
    ! No devices available

! Doctor found 

2 类问题。

Answer 1

对于线程“main” java.lang.NullPointerException
关于文件 gradle-wrapper.properties ， 我变了:
distributionUrl=https://services.gradle.org/distributions/gradle-4.10.2-all.zip
distributionUrl=https://services.gradle.org/distributions/gradle-5.6.2-all.zip
那么请尝试 flutter clean然后运行