我已经在我的应用程序中集成了一个firebase实时数据库,并且我得到了
java.lang.NullPointerException: Firebase Database component is not present
当我尝试使用以下代码创建Firebase数据库的实例时,
FirebaseApp firebaseApp = FirebaseApp.initializeApp(this);
mFirebaseInstance = FirebaseDatabase.getInstance(firebaseApp);
我也尝试过这个
mFirebaseInstance = FirebaseDatabase.getInstance();
每次遇到错误Firebase Database component is not present.
下面是项目gradle文件代码:
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.2.0'
//classpath 'com.google.gms:google-services:4.2.0'
classpath 'com.google.gms:google-services:3.2.1'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects{
repositories {
mavenCentral()
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
下面是我添加的依赖项 依赖项:
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
//implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'androidx.appcompat:appcompat:1.0.0'
//implementation 'com.android.support:design:28.0.0'
implementation 'com.google.android.material:material:1.0.0-rc01'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
// Firebase
implementation 'com.google.firebase:firebase-core:17.0.0'
implementation 'com.google.firebase:firebase-messaging:19.0.1'
implementation 'com.google.firebase:firebase-auth:18.0.0'
implementation 'android.arch.work:work-runtime:1.0.1'
// Firebase real time databse
implementation 'com.google.firebase:firebase-database:17.0.0'
// Glide
implementation 'com.github.bumptech.glide:glide:4.9.0'
annotationProcessor 'com.github.bumptech.glide:compiler:4.9.0'
// Link preview
implementation 'io.github.ponnamkarthik:richlinkpreview:1.0.9'
implementation 'org.jsoup:jsoup:1.10.2'
// Piccaso
implementation 'com.squareup.picasso:picasso:2.71828'
//AdMob
implementation 'com.google.android.gms:play-services-ads:18.0.0'
// Needed to fix a dependency conflict with FirebaseUI'
implementation 'androidx.arch.core:core-runtime:2.0.1'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
androidTestImplementation 'androidx.test:rules:1.2.0'
}
apply plugin: 'com.google.gms.google-services'
我还尝试更改数据库依赖版本,更改类路径并更新google-services.json
文件,但仍然遇到相同的错误。
答案 0 :(得分:1)
只需删除该软件包的android和ios文件夹并输入
flutter create .