我想從我的數據庫中獲取所有孩子。我嘗試了幾乎類似於Google Developers發佈的YouTube上類似的代碼,但之後進行了更改。我只想獲取下面的userdata的所有信息(有用戶的配置文件)。 我的數據庫看起來像: Firebase數據庫獲取所有孩子
,我想那是在userdata
所有信息這裏是我的代碼。
FirebaseDatabase database5 = FirebaseDatabase.getInstance();
DatabaseReference myRef5 = database5.getReference("userdata");
myRef5.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and again
// whenever data at this location is updated.
Map<String, String> map = dataSnapshot.getValue(Map.class);
map.getClass();
Log.i("Mufz", "Value is: " + map.getClass());
// Toast.makeText(getApplicationContext(), `value3.toString(), Toast.LENGTH_SHORT).show();`
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
Log.w("TAG", "Failed to read value.", error.toException());
// Toast.makeText(getApplicationContext(), error.toException().toString(), Toast.LENGTH_SHORT).show();
}
});
運行這個沒有什麼後會發生,它運行prevoroius活動或有錯誤來
08-16 19:29:47.225 32507-32507/com.samo.facedatefb E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.samo.facedatefb, PID: 32507
com.google.firebase.database.DatabaseException: Class java.util.Map has generic type parameters, please use GenericTypeIndicator instead
at com.google.android.gms.internal.zzaln.zzb(Unknown Source)
at com.google.android.gms.internal.zzaln.zza(Unknown Source)
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source)
at com.samo.facedatefb.MapsActivity$3.onDataChange(MapsActivity.java:306)
at com.google.android.gms.internal.zzaie.zza(Unknown Source)
at com.google.android.gms.internal.zzaje.zzcta(Unknown Source)
at com.google.android.gms.internal.zzajh$1.run(Unknown Source)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5549)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:964)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:759)
凡可能是一個問題嗎?謝謝。
謝謝,但仍然是相同的錯誤。 – Samo