我已经编码12个小时了。直到出现此错误，我才编译我的代码。现在我无法解决。无法将对象转换为String。看来我必须转换这些位置，但是我已经在HomeFragment中进行转换。我仍然收到此错误。我在StackOverflow上进行了搜索，但是没有人的代码或建议无法解决该问题。
这是我的HomeFragment：
public class HomeFragment extends Fragment {
private RecyclerView mUsersList;
private DatabaseReference mUserDatabase;
private View mView;
private FirebaseAuth mAuth;
ProgressDialog mProgressDialog;
public HomeFragment() {
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mView = inflater.inflate(R.layout.fragment_home, container, false);
mUsersList = (RecyclerView) mView.findViewById(R.id.users_list);
mUsersList.setHasFixedSize(true);
mUsersList.setLayoutManager(new LinearLayoutManager(getActivity()));
mProgressDialog = new ProgressDialog(getActivity());
mProgressDialog.setTitle("İşlemler yapılıyor");
mProgressDialog.setMessage("İşlemleriniz yapılırken lütfen bekleyiniz");
mProgressDialog.setCanceledOnTouchOutside(true);
mAuth = FirebaseAuth.getInstance();
if (mAuth.getCurrentUser() != null) {
String cUID = mAuth.getCurrentUser().getUid();
mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Veriler").child(cUID);
ValueEventListener eventListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String sFirma = dataSnapshot.child("sFirma").getValue(String.class);
String sNot = dataSnapshot.child("sNot").getValue(String.class);
String sServis = dataSnapshot.child("sServis").getValue(String.class);
String sYakit = dataSnapshot.child("sYakit").getValue(String.class);
String veri = dataSnapshot.child("veri").getValue(String.class);
String zaman = dataSnapshot.child("zaman").getValue(String.class);
String nFirma = dataSnapshot.child("nFirma").getValue(String.class);
String nAlici_firma = dataSnapshot.child("nAlici_firma").getValue(String.class);
String nArac = dataSnapshot.child("nArac").getValue(String.class);
String nNot = dataSnapshot.child("nNot").getValue(String.class);
String nYakit = dataSnapshot.child("nYakit").getValue(String.class);
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
};
mUserDatabase.addListenerForSingleValueEvent(eventListener);
}
return mView;
}
@Override
public void onStart() {
super.onStart();
final FirebaseRecyclerAdapter<Users, UsersViewHolder>firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Users, UsersViewHolder>(Users.class, R.layout.user_single_layout, UsersViewHolder.class, mUserDatabase) {
@Override
protected void populateViewHolder(final UsersViewHolder viewHolder, final Users model, final int position) {
viewHolder.setSfirma(model.getsFirma());
viewHolder.setSservis(model.getsServis());
viewHolder.setSyakit(model.getsYakit());
viewHolder.setSnot(model.getsNot());
viewHolder.setNfirma(model.getnFirma());
viewHolder.setNalici_firma(model.getnAlici_firma());
viewHolder.setNarac(model.getnArac());
viewHolder.setNyakit(model.getsYakit());
viewHolder.setNnot(model.getnNot());
viewHolder.setVeri(model.getVeri());
viewHolder.setZaman(model.getZaman());
viewHolder.mView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
new AlertDialog.Builder(getActivity())
.setIcon(android.R.drawable.ic_dialog_alert)
.setTitle("Veriyi silmek")
.setMessage("Bu veriyi silmek ister misiniz?")
.setPositiveButton("Evet", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Log.i("position3", Integer.toString(position));
mUserDatabase.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
mProgressDialog.show();
try {
mUsersList.removeViewAt(position);
notifyItemRemoved(position);
notifyDataSetChanged();
} catch (Exception e) {
e.printStackTrace();
}
//BURADA BİR ÖNCEKİ HATANDA İLK VERİ TABANINDAN SİLİP SONRA EKRANDAN SİLMEYE ÇALIŞTIN
//BU DA SANA NULL POINTER HATASI DÖNDÜRDÜ UNUTMA!!!
mUserDatabase.child(model.getZaman()).removeValue().addOnCompleteListener(new OnCompleteListener<Void>() {
@Override
public void onComplete(@NonNull Task<Void> task) {
if (task.isSuccessful()) {
mProgressDialog.dismiss();
} else {
Toast.makeText(getActivity(), "Silinirken hata oluştu", Toast.LENGTH_SHORT).show();
}
}
});
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
})
.setNegativeButton("Hayır", null)
.show();
return true;
}
});
}
};
mUsersList.setAdapter(firebaseRecyclerAdapter);
firebaseRecyclerAdapter.notifyDataSetChanged();
}
public static class UsersViewHolder extends RecyclerView.ViewHolder {
private View mView;
public UsersViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setSfirma(String sFirma) {
TextView setFirma = mView.findViewById(R.id.user_firma_ismi);
setFirma.setText("Firma İsmi : " + sFirma);
}
public void setSservis(String sServis) {
TextView setServis = mView.findViewById(R.id.user_servis_adedi);
setServis.setText("Servis Adedi : " + sServis);
}
public void setSyakit(String sYakit) {
TextView setYakit = mView.findViewById(R.id.user_harcanan_yakit);
setYakit.setText("Yakit : " + sYakit);
}
public void setSnot(String sNot) {
TextView setNot = mView.findViewById(R.id.user_gunluk_not);
setNot.setText("Not : " + sNot);
}
public void setNfirma(String nFirma) {
TextView setNFirma = mView.findViewById(R.id.user_firma_ismi);
setNFirma.setText("Firma İsmi : " + nFirma);
}
public void setNalici_firma(String nAlici_firma) {
TextView setNAliciFirma = mView.findViewById(R.id.user_alici_firma_ismi);
setNAliciFirma.setText("Alici Firma İsmi : " + nAlici_firma);
}
public void setNarac(String nArac) {
TextView setNarac = mView.findViewById(R.id.user_servis_adedi);
setNarac.setText("Nakliyat Adedi : " + nArac);
}
public void setNyakit(String nYakit) {
TextView setNYakit = mView.findViewById(R.id.user_harcanan_yakit);
setNYakit.setText("Harcanan Yakit : " + nYakit);
}
public void setNnot(String nNot) {
TextView setNNot = mView.findViewById(R.id.user_gunluk_not);
setNNot.setText("Firma İsmi : " + nNot);
}
public void setVeri(String veri) {
}
public void setZaman(String zaman) {
}
}
}
这是我的Users.java课：
@IgnoreExtraProperties
public class Users {
public String sFirma;
public String sServis;
public String sYakit;
public String sNot;
public String nFirma;
public String nAlici_firma;
public String nArac;
public String nYakit;
public String nNot;
public String veri;
public String zaman;
public Users(String sFirma, String sServis, String sYakit, String sNot, String nFirma, String nAlici_firma, String nArac, String nYakit, String nNot, String veri, String zaman) {
this.sFirma = sFirma;
this.sServis = sServis;
this.sYakit = sYakit;
this.sNot = sNot;
this.nFirma = nFirma;
this.nAlici_firma = nAlici_firma;
this.nArac = nArac;
this.nYakit = nYakit;
this.nNot = nNot;
this.veri = veri;
this.zaman = zaman;
}
public Users(){
}
@Exclude
public String getsFirma() {
return sFirma;
}
public void setsFirma(String sFirma) {
this.sFirma = sFirma;
}
@Exclude
public String getsServis() {
return sServis;
}
public void setsServis(String sServis) {
this.sServis = sServis;
}
@Exclude
public String getsYakit() {
return sYakit;
}
public void setsYakit(String sYakit) {
this.sYakit = sYakit;
}
@Exclude
public String getsNot() {
return sNot;
}
public void setsNot(String sNot) {
this.sNot = sNot;
}
@Exclude
public String getnFirma() {
return nFirma;
}
public void setnFirma(String nFirma) {
this.nFirma = nFirma;
}
@Exclude
public String getnAlici_firma() {
return nAlici_firma;
}
public void setnAlici_firma(String nAlici_firma) {
this.nAlici_firma = nAlici_firma;
}
@Exclude
public String getnArac() {
return nArac;
}
public void setnArac(String nArac) {
this.nArac = nArac;
}
@Exclude
public String getnYakit() {
return nYakit;
}
public void setnYakit(String nYakit) {
this.nYakit = nYakit;
}
@Exclude
public String getnNot() {
return nNot;
}
public void setnNot(String nNot) {
this.nNot = nNot;
}
@Exclude
public String getVeri() {
return veri;
}
public void setVeri(String veri) {
this.veri = veri;
}
@Exclude
public String getZaman() {
return zaman;
}
public void setZaman(String zaman) {
this.zaman = zaman;
}
}
错误日志：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.anild.servo, PID: 17495
com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.anild.servo.Users
at com.google.android.gms.internal.zg.zzb(Unknown Source)
at com.google.android.gms.internal.zg.zza(Unknown Source)
at com.google.firebase.database.DataSnapshot.getValue(Unknown Source)
at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:22)
at com.firebase.ui.database.ObservableSnapshotArray.getObject(ObservableSnapshotArray.java:141)
at com.firebase.ui.database.CachingObservableSnapshotArray.getObject(CachingObservableSnapshotArray.java:40)
at com.firebase.ui.database.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:127)
at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:164)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6673)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6714)
at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5647)
at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5913)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5752)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5748)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2232)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1559)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1519)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:614)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3812)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3529)
at android.support.v7.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1767)
at android.support.v7.widget.RecyclerView$1.run(RecyclerView.java:356)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:603)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5525)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:730)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:620)
答案 0 :(得分：0)
if (mAuth.getCurrentUser() != null) {
String cUID = mAuth.getCurrentUser().getUid();
mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Veriler").child(cUID);
ValueEventListener eventListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Users muser = dataSnapshot.child("sFirma").getValue(Users.class);
Users mnewuser = new User();
String sFirma = muser.getsFirma();
String sServis= muser.getsServis();
String sYakit= muser.getsYakit();
String sNot= muser.getsNot();
String nFirma= muser.getnFirma();
String nAlici_firma= muser.getnAlici_firma();
String nArac= muser.getnArac();
String nYakit= muser.getnYakit();
String nNot= muser.getnNot();
String veri= muser.getveri();
String zaman= muser.getzaman();
mnewuser.setsFirma(sFirma);
//set rest of your string in model as above
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
};
mUserDatabase.addListenerForSingleValueEvent(eventListener);
}
答案 1 :(得分：0)
尝试如下更改您的onDataChange方法：
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String sFirma = dataSnapshot.child("sFirma").getValue(Users.class);
String sNot = dataSnapshot.child("sNot").getValue(Users.class);
String sServis = dataSnapshot.child("sServis").getValue(Users.class);
String sYakit = dataSnapshot.child("sYakit").getValue(Users.class);
String veri = dataSnapshot.child("veri").getValue(Users.class);
String zaman = dataSnapshot.child("zaman").getValue(Users.class);
String nFirma = dataSnapshot.child("nFirma").getValue(Users.class);
String nAlici_firma = dataSnapshot.child("nAlici_firma").getValue(Users.class);
String nArac = dataSnapshot.child("nArac").getValue(Users.class);
String nNot = dataSnapshot.child("nNot").getValue(Users.class);
String nYakit = dataSnapshot.child("nYakit").getValue(Users.class);
}