即使在发送邮件后Firebase数据库也不会更新，我收到错误：
30165/? A/FirebaseApp: Firebase API initialization failure.
java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.google.firebase.FirebaseApp.zza(Unknown Source)
at com.google.firebase.FirebaseApp.initializeApp(Unknown Source)
at com.google.firebase.FirebaseApp.initializeApp(Unknown Source)
at com.google.firebase.FirebaseApp.zzbu(Unknown Source)
at com.google.firebase.provider.FirebaseInitProvider.onCreate(Unknown Source)
at android.content.ContentProvider.attachInfo(ContentProvider.java:1730)
at android.content.ContentProvider.attachInfo(ContentProvider.java:1705)
at com.google.firebase.provider.FirebaseInitProvider.attachInfo(Unknown Source)
at android.app.ActivityThread.installProvider(ActivityThread.java:5116)
at android.app.ActivityThread.installContentProviders(ActivityThread.java:4700)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4640)
at android.app.ActivityThread.access$1500(ActivityThread.java:156)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:211)
at android.app.ActivityThread.main(ActivityThread.java:5371)
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:945)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:740)
Caused by: java.lang.IncompatibleClassChangeError: The method 'java.io.File android.support.v4.content.ContextCompat.getNoBackupFilesDir(android.content.Context)' was expected to be of type virtual but instead was found to be of type direct (declaration of 'java.lang.reflect.ArtMethod' appears in /system/framework/core-libart.jar)
at com.google.firebase.iid.zzg.zzeC(Unknown Source)
at com.google.firebase.iid.zzg.<init>(Unknown Source)
at com.google.firebase.iid.zzg.<init>(Unknown Source)
at com.google.firebase.iid.zzd.zzb(Unknown Source)
at com.google.firebase.iid.FirebaseInstanceId.getInstance(Unknown Source)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.google.firebase.FirebaseApp.zza(Unknown Source)
at com.google.firebase.FirebaseApp.initializeApp(Unknown Source)
at com.google.firebase.FirebaseApp.initializeApp(Unknown Source)
at com.google.firebase.FirebaseApp.zzbu(Unknown Source)
at com.google.firebase.provider.FirebaseInitProvider.onCreate(Unknown Source)
at android.content.ContentProvider.attachInfo(ContentProvider.java:1730)
at android.content.ContentProvider.attachInfo(ContentProvider.java:1705)
at com.google.firebase.provider.FirebaseInitProvider.attachInfo(Unknown Source)
at android.app.ActivityThread.installProvider(ActivityThread.java:5116)
at android.app.ActivityThread.installContentProviders(ActivityThread.java:4700)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4640)
at android.app.ActivityThread.access$1500(ActivityThread.java:156)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1412)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:211)
at android.app.ActivityThread.main(ActivityThread.java:5371)
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:945)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:740)
02-03 17:55:18.351 30165-30209/com.google.firebase.udacity.friendlychat E/FA: Task exception on worker thread: java.lang.IncompatibleClassChangeError: The method 'java.io.File android.support.v4.content.ContextCompat.getNoBackupFilesDir(android.content.Context)' was expected to be of type virtual but instead was found to be of type direct (declaration of 'java.lang.reflect.ArtMethod' appears in /system/framework/core-libart.jar): com.google.android.gms.measurement.internal.zzt.zzEd(Unknown Source)
我已经将数据库的规则更改为：
{
"rules": {
".read": true,
".write": true
}
}
我项目中的依赖项：
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:design:24.2.0'
compile 'com.android.support:appcompat-v7:24.2.0'
// Displaying images
compile 'com.github.bumptech.glide:glide:3.6.1'
compile 'com.google.firebase:firebase-core:9.0.0'
compile 'com.google.firebase:firebase-database:9.0.0'
apply plugin: 'com.google.gms.google-services'
}
代码应该允许用户在EditText字段中输入并按send，以便消息可以存储在firebase DB中。：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mUsername = ANONYMOUS;
mFirebaseDatabase = FirebaseDatabase.getInstance();
mMessagesDatabaseReference = mFirebaseDatabase.getReference().child("messages");
// Initialize references to views
mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
mMessageListView = (ListView) findViewById(R.id.messageListView);
mPhotoPickerButton = (ImageButton) findViewById(R.id.photoPickerButton);
mMessageEditText = (EditText) findViewById(R.id.messageEditText);
mSendButton = (Button) findViewById(R.id.sendButton);
// Send button sends a message and clears the EditText
mSendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FriendlyMessage friendlyMessage = new FriendlyMessage(mMessageEditText.getText().toString(), mUsername, null);
mMessagesDatabaseReference.push().setValue(friendlyMessage);
// Clear input box
mMessageEditText.setText("");
}
});
答案 0 :(得分：3)
您需要使用setValue在Firebase数据库中设置消息。
mSendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FriendlyMessage friendlyMessage = new FriendlyMessage(mMessageEditText.getText().toString(), mUsername, null);
mMessagesDatabaseReference.push().setValue(friendlyMessage);
// Clear input box
mMessageEditText.setText("");
}
});
答案 1 :(得分：0)
我认为问题出在依赖关系中，通过替换来解决：
compile 'com.google.firebase:firebase-core:9.0.0'
compile 'com.google.firebase:firebase-database:9.0.0'
由：
compile 'com.google.firebase:firebase-core:11.8.0'
compile 'com.google.firebase:firebase-database:11.8.0'