<分区>
我正在尝试遵循有关使用 Firbase 数据库的教程，但我不确定为什么会发生这种情况，因为这是我第一次尝试。
我在我的应用程序 logcat 中收到此异常。
03-09 02:39:57.373 15997-15997/com.example.android.clouddatabase E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.android.clouddatabase, PID: 15997
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android.clouddatabase/com.example.android.clouddatabase.MainActivity}: java.lang.IllegalStateException: FirebaseApp with name [DEFAULT] doesn't exist.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2491)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2564)
at android.app.ActivityThread.access$800(ActivityThread.java:170)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1441)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5576)
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:955)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:750)
Caused by: java.lang.IllegalStateException: FirebaseApp with name [DEFAULT] doesn't exist.
at com.google.firebase.FirebaseApp.getInstance(Unknown Source)
at com.google.firebase.FirebaseApp.getInstance(Unknown Source)
at com.google.firebase.database.FirebaseDatabase.getInstance(Unknown Source)
at com.example.android.clouddatabase.MainActivity.onCreate(MainActivity.java:46)
at android.app.Activity.performCreate(Activity.java:6041)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1111)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2437)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2564)
at android.app.ActivityThread.access$800(ActivityThread.java:170)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1441)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5576)
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:955)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:750)
这是我的 build.gradle 应用程序文件的样子
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
defaultConfig {
applicationId "com.example.android.clouddatabase"
minSdkVersion 15
targetSdkVersion 26
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
compile 'com.android.support:design:26.1.0'
compile 'com.google.firebase:firebase-database:9.4.0'
compile 'com.google.firebase:firebase-auth:9.4.0'
compile 'com.google.firebase:firebase-core:9.4.0'
compile 'com.android.support:recyclerview-v7:26.1.0'
compile 'com.android.support:multidex:1.0.1'
}
我尝试了很多解决方案，但似乎没有一个有效。 所以我愿意接受任何建议