Initializing gradle...
Resolving dependencies...
Gradle task 'assembleDebug'...
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:9: error: cannot find symbol
import androidx.annotation.NonNull;
                          ^
  symbol:   class NonNull
  location: package androidx.annotation
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:10: error: cannot find symbol
import androidx.annotation.Nullable;
                          ^
  symbol:   class Nullable
  location: package androidx.annotation
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:253: error: cannot find symbol
          public void onFailure(@NonNull Exception e) {
                                 ^
  symbol: class NonNull
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:274: error: cannot find symbol
                    public Void apply(@NonNull Transaction transaction)
                                       ^
  symbol: class NonNull
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:272: error: cannot find symbol
                    @Nullable
                     ^
  symbol: class Nullable
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:503: error: cannot find symbol
                    public void onFailure(@NonNull Exception e) {
                                           ^
  symbol: class NonNull
/Users/ipatel/Documents/AAAA/FlutterSetup/flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.9.0/android/src/main/java/io/flutter/plugins/firebase/cloudfirestore/CloudFirestorePlugin.java:558: error: cannot find symbol
                    public void onFailure(@NonNull Exception e) {
                                           ^
  symbol: class NonNull
7 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':cloud_firestore:compileDebugJavaWithJavac'.
> 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 4s
Finished with error: Gradle task assembleDebug failed with exit code 1

不知道为什么会发现“以上错误”？我只是尝试在系统中连接设备并运行。

以前，我尝试在未安装Android Studio的情况下通过VS
Code在设备上运行应用程序。因此，我已按照https://medium.com/@aubykhan/setting-up-flutter-
without-android-studio-6f7abdeb353c本教程进行操作，并通过终端手动安装了Gradle。

以下是我的终端的一些历史记录：

431 brew install gradle
432 brew cask install java
433 brew install gradle
434 flutter config –gradle-dir / usr / local / opt / gradle
435 flutter –version
436 clear
437 flutter doctor
438 sdkmanager“ system-images; android-21;默认值; x86_64“
439 vi〜/ .bash_profile
440打开$ HOME / .bash_profile

我以为问题可能是系统找到Gradle的两个路径还是问题是其他？不知道，但是我怎么解决这个问题呢？