如何从android中的firebase获取对象?

how to get the object from firebase in android?

我有这样的用户类

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public class User{
int id;
String description;
String shortDescription;
String photo;

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getShortDescription() {
    return shortDescription;
}

public void setShortDescription(String shortDescription) {
    this.shortDescription = shortDescription;
}

public String getPhoto() {
    return photo;
}

public void setPhoto(String photo) {
    this.photo = photo;
}
}

我正在使用FirebaseRecyclerAdapter获取存储在我的firebase上的用户,如下所示

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 FirebaseRecyclerAdapter<User, UserHolder> adapter =
            new FirebaseRecyclerAdapter<User, UserHolder>(
                    User.class,
                    android.R.layout.two_line_list_item,
                    UserHolder.class,
                    mRef) {
                @Override
                protected void populateViewHolder(UserHolder userHolder, User u, int i) {
                    userHolder.mText.setText(u.getDescription());
                }
            };

但问题是用户对象的firebase密钥是什么时候

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 > -KDY9Pna7XqgFkyCHKFJ

然后它的工作正常,但如果firebase键是这样的

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 > c5755a68-69a7-4464-956e-c2f94d9b387d

这个唯一的ID然后它给出了一个错误

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> com.firebase.client.FirebaseException: Failed to bounce to type

FATAL EXCEPTION: main
Process: in.rofr, PID: 12399
com.firebase.client.FirebaseException: Failed to bounce to type
at com.firebase.client.DataSnapshot.getValue(DataSnapshot.java:183)
at com.firebase.ui.FirebaseRecyclerAdapter.parseSnapshot(FirebaseRecyclerAdapter.java:161)
at com.firebase.ui.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:150)
at com.firebase.ui.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:190)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5465)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5498)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4735)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4611)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1988)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1384)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1347)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:574)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3026)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2903)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3277)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:1183)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
at android.view.View.layout(View.java:15689)
at android.view.ViewGroup.layout(ViewGroup.java:5040)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2116)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1873)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1084)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5990)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)

什么是确切的问题,我没有得到任何人可以帮助我吗?

提前致谢 !!!


尝试将@JsonIgnoreProperties(ignoreUnknown = true)放在类之上

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@JsonIgnoreProperties(ignoreUnknown = true)
public class UserModel {

}

这可能有效,因为Firebase使用Jackson库来序列化/反序列化JSON,并且@JsonIgnoreProperties(ignoreUnknown = true)的使用是忽略新属性(类中未声明的属性),如此处所述https://stackoverflow.com/一个/二百三十三万一千七百零五分之五百四十五万五千五百六十三