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无法转换java类型的对象。字符串输入tiagov。rideabike1.Model。弗雷特斯

firebaseui firebase-realtime-database firebase android

Tiago Vicente · 技术社区 · 7 年前

我正在使用FirebaseUi填充一个RecyclerView,但当我启动应用程序时,什么都没有显示。我看到了很多教程和视频,但都没有效果,也许这是一个愚蠢的问题,但我是android新手,以下是我正在使用的所有代码:

这是模型课

public class Fretes {

    private String mColeta;
    private String mEntrega;
    private String mStatus;


public Fretes() {

    }
    public Fretes(String mColetaLat, String mColetaLong, String mEntregaLat, String mEntregaLong, String mStatus) {
        this.mColeta= mColetaLat;
        this.mEntrega = mEntregaLat;
        this.mStatus = mStatus;
    }

    public String getmColeta() {
        return mColeta;
    }

    public void setmColeta(String mColetaLat) {
        this.mColeta = mColeta;
    }

    public String getmEntrega() {
        return mEntrega;
    }

    public void setmEntrega(String mEntrega) {
        this.mEntrega = mEntrega;
    }


    public String getmStatus() {
        return mStatus;
    }

    public void setmStatus(String mStatus) {
        this.mStatus = mStatus;
    }
}

这是holder类

public class FretesHolder extends RecyclerView.ViewHolder {

    private final TextView text_coleta;
    private final TextView text_entrega;
    private final TextView text_status;

    public FretesHolder(View itemView) {
        super(itemView);

        text_coleta = (TextView) itemView.findViewById(R.id.text_coleta);
        text_entrega = (TextView) itemView.findViewById(R.id.text_entrega);
        text_status = (TextView) itemView.findViewById(R.id.text_status);

    }

    public void setText_coleta(String coleta){
        setText_coleta(coleta);
    }

    public void setText_entrega(String entrega){ setText_entrega(entrega); }

    public void setText_status(String status){ setText_status(status); }
public class FretesHolder extends RecyclerView.ViewHolder {

    private final TextView text_coleta;
    private final TextView text_entrega;
    private final TextView text_status;

    public FretesHolder(View itemView) {
        super(itemView);

        text_coleta = (TextView) itemView.findViewById(R.id.text_coleta);
        text_entrega = (TextView) itemView.findViewById(R.id.text_entrega);
        text_status = (TextView) itemView.findViewById(R.id.text_status);

    }

    public void setText_coleta(String coleta){
        setText_coleta(coleta);
    }

    public void setText_entrega(String entrega){ setText_entrega(entrega); }

    public void setText_status(String status){ setText_status(status); }
}

这里是主课堂

public class RecyclerViewTest extends AppCompatActivity {

    private FirebaseRecyclerAdapter<Fretes, FretesHolder> adapter;
    private RecyclerView mRecyclerFretes;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_reclycler_view);


        mRecyclerFretes = (RecyclerView) findViewById(R.id.recyclerTest);
        mRecyclerFretes.setHasFixedSize(true);

        setupAdapter();
    }

    private void setupAdapter() {

        Query query = FirebaseDatabase.getInstance()
                .getReference()
                .child("test");

        FirebaseRecyclerOptions<Fretes> options =
                new FirebaseRecyclerOptions.Builder<Fretes>()
                        .setQuery(query, Fretes.class)
                        .build();

        adapter = new FirebaseRecyclerAdapter<Fretes, FretesHolder>(options) {
            @Override
            public FretesHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.layout_fretes, parent, false);

                return new FretesHolder(view);
            }

            @Override
            protected void onBindViewHolder(FretesHolder holder, int position, Fretes model) {
                holder.setText_status(model.getmStatus());
                holder.setText_entrega(model.getmEntrega());
                holder.setText_coleta(model.getmColeta());
            }

        };
        mRecyclerFretes.setAdapter(adapter);
    }

    @Override
    public void onStart() {
        super.onStart();
        adapter.startListening();
    }

    @Override
    public void onStop(){
        super.onStop();
        adapter.stopListening();

    }
}

我看不出我错过了什么,也看不出哪里错了,如果能得到一些帮助,我将不胜感激。谢谢

编辑我添加了onCreate上缺少的这一行

 mRecyclerFretes.setLayoutManager(new LinearLayoutManager(this));

现在我发现了这个错误:(

com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type tiagov.rideabike1.Model.Fretes
 at com.google.android.gms.internal.zzear.zzb(Unknown Source:842)
 at com.google.android.gms.internal.zzear.zza(Unknown Source:0)
 at com.google.firebase.database.DataSnapshot.getValue(Unknown Source:10)
 at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:23)
 at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:14)
 at com.firebase.ui.common.BaseCachingSnapshotParser.parseSnapshot(BaseCachingSnapshotParser.java:32)
 at com.firebase.ui.common.BaseObservableSnapshotArray.get(BaseObservableSnapshotArray.java:45)
 at com.firebase.ui.database.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:103)
 at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:118)
 at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6482)
 at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6515)
 at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5458)
 at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5724)
 at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563)
 at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559)
 at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2229)
 at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1556)
 at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1516)
 at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:608)
 at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693)
 at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3410)
 at android.support.v7.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1710)
 at android.support.v7.widget.RecyclerView$1.run(RecyclerView.java:346)
 at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966)
 at android.view.Choreographer.doCallbacks(Choreographer.java:778)
 at android.view.Choreographer.doFrame(Choreographer.java:710)
 at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:952)
 at android.os.Handler.handleCallback(Handler.java:789)
 at android.os.Handler.dispatchMessage(Handler.java:98)
 at android.os.Looper.loop(Looper.java:164)
 at android.app.ActivityThread.main(ActivityThread.java:6567)
 at java.lang.reflect.Method.invoke(Native Method)
 at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

我的数据库 firebase

1 回复 | 直到 7 年前

Frank van Puffelen 7 年前

当您将FirebaseUI适配器连接到位置/查询时,每个 子节点 并尝试将该子节点的属性映射到类中的属性。

位置下的子节点是 mColeta , mEntrega 和 mStatus . 对于其中的每一个,Firebase都创建了一个 Fretes 对象,然后尝试映射属性。每个子节点只有一个名为 true ,因此映射失败。

一种方法是为子节点的JSON添加一个级别:

test
  -Lsdfiuhsaiu
    mColeta: "teste"
    mEntrega: "teste"
    mStatus: "teste"

使用这种结构,有一个额外级别的节点,您的适配器可以找到属性。