fireBaseFireStore.getInstance();导致nullPointerException尝试调用虚拟方法“void com.google.firebase.auth.internal.zzab.zzf(int)”。

我在一个我已经有一段时间没有工作的项目中得到这个错误:

这是错误消息(活动开始时我会纠正):

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.app, PID: 12798
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.app/com.example.app.GettingStarted}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.firebase.auth.internal.zzab.zzf(int)' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2450)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
    at android.app.ActivityThread.access$1200(ActivityThread.java:165)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1373)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5593)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.firebase.auth.internal.zzab.zzf(int)' on a null object reference
    at com.google.firebase.auth.FirebaseAuth.addIdTokenListener(Unknown Source)
    at com.google.firebase.firestore.auth.FirebaseAuthCredentialsProvider.<init>(com.google.firebase:firebase-firestore@@17.1.5:76)
    at com.google.firebase.firestore.FirebaseFirestore.newInstance(com.google.firebase:firebase-firestore@@17.1.5:111)
    at com.google.firebase.firestore.FirestoreMultiDbComponent.get(com.google.firebase:firebase-firestore@@17.1.5:51)
    at com.google.firebase.firestore.FirebaseFirestore.getInstance(com.google.firebase:firebase-firestore@@17.1.5:89)
    at com.google.firebase.firestore.FirebaseFirestore.getInstance(com.google.firebase:firebase-firestore@@17.1.5:74)
    at com.example.app.GettingStarted.onCreate(GettingStarted.java:92)
    at android.app.Activity.performCreate(Activity.java:6102)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2403)

这是一些活动:

public class GettingStarted extends AppCompatActivity implements View.OnClickListener {

public static String RESUME_MATCH_KEY = "resumeMatch";
public static String TAG = "GettingStarted.java";

private FirebaseFirestore firestore;
private FirebaseUser user;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_getting_started);
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            startActivity(new Intent(GettingStarted.this, NewMatchActivity.class));
        }
    });

    user = FirebaseAuth.getInstance().getCurrentUser();
    //FIREBASE FIRESTORE
    firestore = FirebaseFirestore.getInstance(); //this is where the error keeps happening
    FirebaseFirestoreSettings firestoreSettings = new FirebaseFirestoreSettings.Builder()
            .setTimestampsInSnapshotsEnabled(true)
            .build();
    firestore.setFirestoreSettings(firestoreSettings);
(closing tags and rest of the code)

我一直试图通过更新依赖项来解决这个问题,但这并没有改变错误。我还尝试更新google-services.json文件。

谢谢你的帮助!

更新:

以下是我的build.gradle文件:

apply plugin: 'com.android.application'

android {
compileSdkVersion 28
buildToolsVersion '28.0.3'
defaultConfig {
    multiDexEnabled true
    applicationId "com.example.app"
    minSdkVersion 19
    targetSdkVersion 28
    versionCode 59
    versionName "3.6.259"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    vectorDrawables.useSupportLibrary = true
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
dexOptions {

}
lintOptions {

    checkReleaseBuilds false

}
}

 dependencies {
api 'com.android.support:design:28.0.0'
api 'com.android.support:support-v4:28.0.0'
api 'com.android.support:support-vector-drawable:28.0.0'
api 'com.android.support:recyclerview-v7:28.0.0'
api 'com.android.support:cardview-v7:28.0.0'
api 'com.android.support:appcompat-v7:28.0.0'
api 'com.android.support.constraint:constraint-layout:1.1.3'
api "com.android.support:customtabs:28.0.0"

api "com.google.android.gms:play-services-base:16.1.0"
api "com.google.android.gms:play-services-auth:16.0.1"
api "com.google.android.gms:play-services-flags:16.0.1"

api 'com.crashlytics.sdk.android:crashlytics:2.9.8'

api 'com.google.firebase:firebase-core:16.0.6'
api 'com.google.firebase:firebase-messaging:17.3.4'
api 'com.google.firebase:firebase-appindexing:17.1.0'
api 'com.google.firebase:firebase-invites:16.0.6'

api "com.firebaseui:firebase-ui-auth:4.1.0"
api 'com.google.firebase:firebase-firestore:17.1.5'
androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
implementation fileTree(include: ['*.jar'], dir: 'libs')
}
// Add to the bottom of the file - this is for Google Firebase
apply plugin: 'com.google.gms.google-services'

第二个是:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
repositories {
    google()
    jcenter()

}
dependencies {
    classpath 'com.android.tools.build:gradle:3.3.0'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files

    // Add this line
    classpath 'com.google.gms:google-services:4.2.0'
}
}

allprojects {
repositories {
    jcenter()
    maven {
        url "https://maven.google.com"
    }
    google()
}
}

task clean(type: Delete) {
delete rootProject.buildDir
}