它的firebase错误我无法得到它请帮助我解决并告诉我它发生的原因。 对不起英语并试着解决它
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.kunalgharate.weedon, PID: 16793
com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.kunalgharate.weedon.Friends
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:160)
at com.firebase.ui.database.CachingObservableSnapshotArray.getObject(CachingObservableSnapshotArray.java:40)
at com.firebase.ui.database.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:180)
at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:217)
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:871)
at android.view.Choreographer.doCallbacks(Choreographer.java:683)
at android.view.Choreographer.doFrame(Choreographer.java:616)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:857)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6123)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)
申请已终止。
活动主要
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.squareup.picasso.Picasso;
import de.hdodenhof.circleimageview.CircleImageView;
public class MainActivity extends AppCompatActivity {
private FirebaseAuth mAuth;
RecyclerView mSubsList;
DatabaseReference mFriendsDatabase;
DatabaseReference mUsersDatabase;
private String mCurrent_user_id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.main_page_toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("WeedON");
mAuth = FirebaseAuth.getInstance();
mCurrent_user_id = mAuth.getCurrentUser().getUid();
mSubsList =findViewById(R.id.subscribes_list);
mSubsList.setHasFixedSize(true);
mSubsList.setLayoutManager(new LinearLayoutManager(this));
mFriendsDatabase = FirebaseDatabase.getInstance().getReference().child("subscribers").child(mCurrent_user_id);
mFriendsDatabase.keepSynced(true);
mUsersDatabase = FirebaseDatabase.getInstance().getReference().child("Users");
mUsersDatabase.keepSynced(true);
}
private void signOut() {
mAuth.signOut();
}
@Override
protected void onStart() {
super.onStart();
FirebaseRecyclerAdapter<Friends,MainViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Friends,MainViewHolder>(
Friends.class,
R.layout.single_service_layout,
MainViewHolder.class,
mFriendsDatabase
)
{
@Override
protected void populateViewHolder(MainViewHolder viewHolder, Friends model, int position) {
}
};
mSubsList.setAdapter(firebaseRecyclerAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.main_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
if(item.getItemId() == R.id.main_logout_btn){
// mUserRef.child("online").setValue(ServerValue.TIMESTAMP);
signOut();
Intent intent = new Intent(this, LoginActivity.class);
startActivity(intent);
finish();
// sendToStart();
}
if(item.getItemId() == R.id.main_settings_btn){
Intent settingsIntent = new Intent(MainActivity.this, SettingsActivity.class);
startActivity(settingsIntent);
}
if(item.getItemId() == R.id.main_all_btn){
Intent settingsIntent = new Intent(MainActivity.this, AllServicesActivity.class);
startActivity(settingsIntent);
}
return true;
}
public static class MainViewHolder extends RecyclerView.ViewHolder{
View mView;
public MainViewHolder(View itemView) {
super(itemView);
mView =itemView;
}
}
}
数据库截图
其未显示布局错误或代码错误我该怎么办?
答案 0 :(得分:1)
通过查看您的数据库,我可以看到您的mFriendsDatabase DatabseReference指向某些&#39; String&#39;值和你告诉你的firebaseRecyclerAdapter那些类型为&#39; Friends,这就是抛出异常的原因。大概可能是你在保存值到数据库时犯了一个错误,而不是保存你正在保存一些的Friends对象字符串值。但如果不是这样,您可以将firebaseRecyclerAdapter更改为此...
FirebaseRecyclerAdapter<String,MainViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<String,MainViewHolder>(
String.class,
R.layout.single_service_layout,
MainViewHolder.class,
mFriendsDatabase
)
{
@Override
protected void populateViewHolder(MainViewHolder viewHolder, String mString, int position) {
Log.d("TAG",mString);
}
};
mSubsList.setAdapter(firebaseRecyclerAdapter);
答案 1 :(得分:0)
要显示这些消息,请使用以下代码:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("subscribers").child(mCurrent_user_id);
ValueEventListener eventListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String message = ds.getValue(String.class);
Log.d("TAG", message);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {}
};
uidRef.addListenerForSingleValueEvent(eventListener);