从 firebase 中的多节点检索产品

Question

Hello everyone! i am facing an issue, the given code is showing me same product  multiple times rather than showing all the available products. Can some one help me its my FYP and i really need to solve the issue today.

Details.

package com.rent.shopping;

import android.content.Intent;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import androidx.annotation.NonNull;

import androidx.appcompat.app.ActionBarDrawerToggle;

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.app.AppCompatDelegate;

import androidx.appcompat.widget.Toolbar;

import androidx.core.view.GravityCompat;

import androidx.drawerlayout.widget.DrawerLayout;

import androidx.recyclerview.widget.LinearLayoutManager;

import androidx.recyclerview.widget.RecyclerView;

import com.firebase.ui.database.FirebaseRecyclerAdapter;

import com.firebase.ui.database.FirebaseRecyclerOptions;

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import com.google.android.material.navigation.NavigationView;

import com.google.firebase.database.DataSnapshot;

import com.google.firebase.database.DatabaseError;

import com.google.firebase.database.DatabaseReference;

import com.google.firebase.database.FirebaseDatabase;

import com.google.firebase.database.ValueEventListener;

import com.rent.shopping.Model.Products;

import com.rent.shopping.Prevalent.Prevalent;

import com.rent.shopping.ViewHolder.ProductViewHolder;

import com.squareup.picasso.Picasso;

import java.util.ArrayList;

import java.util.Objects;

import de.hdodenhof.circleimageview.CircleImageView;

import io.paperdb.Paper;

public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {

private DatabaseReference ProductsRef;

DrawerLayout drawerLayout;

NavigationView navigationView;

Toolbar toolbar;

private RecyclerView recyclerView;

RecyclerView.LayoutManager layoutManager;

ArrayList<String> vendorIds = new ArrayList<String>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
    ProductsRef = FirebaseDatabase.getInstance().getReference().child("Vendors");
    drawerLayout=findViewById(R.id.drawer_layout);
    navigationView=findViewById(R.id.nav_view);
    toolbar=findViewById(R.id.toolbar);
    androidx.appcompat.widget.Toolbar toolbar = (androidx.appcompat.widget.Toolbar) findViewById(R.id.toolbar);
    toolbar.setTitle("Home");
    setSupportActionBar(toolbar);
    navigationView.bringToFront();
    ActionBarDrawerToggle toggle=new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.navigation_drawer_open,R.string.navigation_drawer_close);
    drawerLayout.addDrawerListener(toggle);
    toggle.syncState();
    navigationView.setNavigationItemSelectedListener(this);
    View headerView = navigationView.getHeaderView(0);
    TextView userNameTextView = headerView.findViewById(R.id.user_profile_name);
    CircleImageView profileImageView = headerView.findViewById(R.id.user_profile_image);
    userNameTextView.setText(Prevalent.currentOnlineUser.getName());
    Picasso.get().load(Prevalent.currentOnlineUser.getImage()).placeholder(R.drawable.profile).into(profileImageView);
    recyclerView = findViewById(R.id.recycler_menu);
    recyclerView.setHasFixedSize(true);
    layoutManager = new LinearLayoutManager(this);
    recyclerView.setLayoutManager(layoutManager);
    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(view -\> {
        Intent intent = new Intent(HomeActivity.this,CartActivity.class);
        startActivity(intent);
    });
}
@Override
protected void onStart() {
    super.onStart();

// Get a reference to the vendors node

// Retrieve vendor IDs

        ProductsRef.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                    for (DataSnapshot vendorSnapshot : dataSnapshot.getChildren()) {
                        String vendorId = vendorSnapshot.getKey();

                        ProductsRef.child(Objects.requireNonNull(vendorId)).child("Products").addListenerForSingleValueEvent(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot snapshot) {
                                FirebaseRecyclerOptions\<Products\> options =
                                        new FirebaseRecyclerOptions.Builder\<Products\>()
                                                .setQuery(ProductsRef, Products.class)
                                                .build();
                                FirebaseRecyclerAdapter\<Products, ProductViewHolder\> adapter =
                                        new FirebaseRecyclerAdapter\<Products, ProductViewHolder\>(options) {
                                            @Override
                                            protected void onBindViewHolder(@NonNull ProductViewHolder holder, int position, @NonNull final Products model) {
                                                for (DataSnapshot url : snapshot.getChildren()) {

                                                    holder.txtProductName.setText(url.child("pname").getValue(String.class));
                                                    holder.txtProductDescription.setText(url.child("description").getValue(String.class));
                                                    holder.txtProductPrice.setText("Price = " + url.child("price").getValue(String.class) + "Rs.");
                                                    String productImage = url.child("image").getValue(String.class);
                                                    Picasso.get().load(productImage).into(holder.imageView);

                                                    holder.itemView.setOnClickListener(new View.OnClickListener() {
                                                        @Override
                                                        public void onClick(View view) {
                                                            Intent intent = new Intent(HomeActivity.this, ProductDetailsActivity.class);
                                                            intent.putExtra("pid", url.child("pid").getValue(String.class));
                                                            intent.putExtra("pname", url.child("pname").getValue(String.class));
                                                            intent.putExtra("description", url.child("description").getValue(String.class));
                                                            intent.putExtra("price", url.child("price").getValue(String.class));
                                                            intent.putExtra("image", url.child("image").getValue(String.class));
                                                            startActivity(intent);


                                                        }


                                                    });

                                                }


                                            }
                                            @NonNull
                                            @Override
                                            public ProductViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                                                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.product_items_layout, parent, false);
                                                return new ProductViewHolder(view);
                                            }

                                        };


                                recyclerView.setAdapter(adapter);
                                adapter.startListening();
                                vendorIds.add(vendorId);
                                System.out.println(vendorIds);

                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError error) {

                            }
                        });

                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
                System.out.println("The read failed: " + databaseError.getCode());
            }
        });




}
@Override
public void onBackPressed(){
    if(drawerLayout.isDrawerOpen(GravityCompat.START)){
        drawerLayout.closeDrawer(GravityCompat.START);
    }
    else
    {super.onBackPressed();
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main_menu, menu);
    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    //noinspection SimplifiableIfStatement

//        if (id == R.id.action_settings) {

//            return true;

//        }

return super.onOptionsItemSelected(item);

}

@Override

public boolean onNavigationItemSelected(MenuItem item) {

// Handle navigation view item clicks here.

int id = item.getItemId();

if (id == R.id.nav_cart) {

Intent intent = new Intent(HomeActivity.this,CartActivity.class);

startActivity(intent);

} else if (id == R.id.nav_search) {

Intent intent = new Intent(HomeActivity.this,SearchProductsActivity.class);

startActivity(intent);

}

else if (id == R.id.nav_settings) {

Intent intent=new Intent(HomeActivity.this,SettinsActivity.class);

startActivity(intent);

} else if (id == R.id.nav_logout) {

Paper.book().destroy();

Intent intent=new Intent(HomeActivity.this,MainActivity.class);

intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK |Intent.FLAG_ACTIVITY_CLEAR_TASK );

startActivity(intent);

finish();

}

drawerLayout.closeDrawer(GravityCompat.START);

return true;

}

}

Here is the database look

here is the code i used to upload the products

package com.rent.shopping;


import android.annotation.SuppressLint;
import android.app.ProgressDialog;
import android.content.Intent;
import android.net.Uri;

import android.os.Bundle;
import android.text.TextUtils;

import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.tasks.Continuation;
import com.google.android.gms.tasks.Task;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.UploadTask;


import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Objects;

public class AdminAddNewProductActivity extends AppCompatActivity {
    private String CategoryName, Description, Price, saveCurrentDate, saveCurrentTime ,security ,borowingprice;
    public static String Pname;
    private Button AddNewProductButton ;
    private ImageView InputProductImage;
    private EditText InputProductName, InputProductDescription, InputProductPrice,Securityprice,Borrowingprice;
    private static final int GalleryPick = 1;
    private Uri ImageUri;
    private String productRandomKey, downloadImageUrl;
    private StorageReference ProductImagesRef;
    private DatabaseReference ProductsRef;
    private ProgressDialog loadingBar;
String phone;
EditText PHONE;

    @SuppressLint("MissingInflatedId")
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_add_new_product);
        PHONE=findViewById(R.id.number);

        CategoryName = getIntent().getExtras().get("category").toString();
        ProductImagesRef = FirebaseStorage.getInstance().getReference().child("Product Images");
        ProductsRef = FirebaseDatabase.getInstance().getReference().child("Vendors");
        AddNewProductButton = findViewById(R.id.add_new_product);
        InputProductImage = findViewById(R.id.select_product_image);
        InputProductName = findViewById(R.id.product_name);
        InputProductDescription = findViewById(R.id.product_description);
        InputProductPrice = findViewById(R.id.product_price);

        Securityprice= findViewById(R.id.security_price);
        Borrowingprice= findViewById(R.id.borrowing_price);
        loadingBar = new ProgressDialog(this);

        InputProductImage.setOnClickListener(view -> OpenGallery());


        AddNewProductButton.setOnClickListener(view -> ValidateProductData());
    }


    private void OpenGallery(){
        Intent galleryIntent = new Intent();
        galleryIntent.setAction(Intent.ACTION_GET_CONTENT);
        galleryIntent.setType("image/*");
        startActivityForResult(galleryIntent, GalleryPick);
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode==GalleryPick  &&  resultCode==RESULT_OK  &&  data!=null)
        {
            ImageUri = data.getData();
            InputProductImage.setImageURI(ImageUri);
        }
    }
    private void ValidateProductData() {
        Description = InputProductDescription.getText().toString();
        Price = InputProductPrice.getText().toString();
        Pname = InputProductName.getText().toString();
        security=Securityprice.getText().toString();
        borowingprice=Borrowingprice.getText().toString();
        phone=PHONE.getText().toString().trim();
        if (ImageUri == null)
        {
            Toast.makeText(this, "Product image is mandatory...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(Description))
        {
            Toast.makeText(this, "Please write product description...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(Price))
        {
            Toast.makeText(this, "Please write product Price...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(Pname))
        {
            Toast.makeText(this, "Please write product name...", Toast.LENGTH_SHORT).show();
        }else if (TextUtils.isEmpty(security))
        {
            Toast.makeText(this, "Please write Security fees...", Toast.LENGTH_SHORT).show();
        }else if (TextUtils.isEmpty(borowingprice))
        {
            Toast.makeText(this, "Please write Borrowing price...", Toast.LENGTH_SHORT).show();
        }
        else
        {
            StoreProductInformation();
        }

    }
    private void StoreProductInformation()
    {
        loadingBar.setTitle("Add New Product");
        loadingBar.setMessage("Dear Admin, please wait while we are adding the new product.");
        loadingBar.setCanceledOnTouchOutside(false);
        loadingBar.show();

        Calendar calendar = Calendar.getInstance();

        SimpleDateFormat currentDate = new SimpleDateFormat("MMM dd, yyyy");
        saveCurrentDate = currentDate.format(calendar.getTime());

        SimpleDateFormat currentTime = new SimpleDateFormat("HH:mm:ss a");
        saveCurrentTime = currentTime.format(calendar.getTime());

        productRandomKey = saveCurrentDate + saveCurrentTime;


        final StorageReference filePath = ProductImagesRef.child(ImageUri.getLastPathSegment() + productRandomKey + ".jpg");

        final UploadTask uploadTask = filePath.putFile(ImageUri);

        uploadTask.addOnFailureListener(e -> {
            String message = e.toString();
            Toast.makeText(AdminAddNewProductActivity.this, "Error: " + message, Toast.LENGTH_SHORT).show();
            loadingBar.dismiss();
        }).addOnSuccessListener(taskSnapshot -> {
            Toast.makeText(AdminAddNewProductActivity.this, "Product Image uploaded Successfully...", Toast.LENGTH_SHORT).show();
            Task<Uri> urlTask = uploadTask.continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
                @Override
                public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
                    if (!task.isSuccessful())
                    {
                        throw Objects.requireNonNull(task.getException());
                    }

                    downloadImageUrl = filePath.getDownloadUrl().toString();
                    return filePath.getDownloadUrl();
                }
            }).addOnCompleteListener(task -> {
                if (task.isSuccessful())
                {
                    downloadImageUrl = task.getResult().toString();

                    Toast.makeText(AdminAddNewProductActivity.this, "got the Product image Url Successfully...", Toast.LENGTH_SHORT).show();

                    SaveProductInfoToDatabase();
                }
            });
        });

    }
    private void SaveProductInfoToDatabase()
    {
        HashMap<String, Object> productMap = new HashMap<>();
        productMap.put("pid", productRandomKey);
        productMap.put("date", saveCurrentDate);
        productMap.put("time", saveCurrentTime);
        productMap.put("description", Description);
        productMap.put("image", downloadImageUrl);
        productMap.put("category", CategoryName);
        productMap.put("price", Price);
        productMap.put("Borrowing price", borowingprice);
        productMap.put("Security Fees", security);
        productMap.put("pname", Pname);

        ProductsRef.child(phone).child("Products").child(Pname).updateChildren(productMap)
                .addOnCompleteListener(task -> {
                    if (task.isSuccessful())
                    {
                        Intent intent = new Intent(AdminAddNewProductActivity.this, AdminCategoryActivity.class);
                        startActivity(intent);

                        loadingBar.dismiss();
                        Toast.makeText(AdminAddNewProductActivity.this, "Product is added successfully..", Toast.LENGTH_SHORT).show();
                    }
                    else
                    {
                        loadingBar.dismiss();
                        String message = Objects.requireNonNull(task.getException()).toString();
                        Toast.makeText(AdminAddNewProductActivity.this, "Error: " + message, Toast.LENGTH_SHORT).show();
                    }

                });

    }}


    

package com.rent.shopping;


import android.annotation.SuppressLint;
import android.app.ProgressDialog;
import android.content.Intent;
import android.net.Uri;

import android.os.Bundle;
import android.text.TextUtils;

import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.tasks.Continuation;
import com.google.android.gms.tasks.Task;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.UploadTask;


import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Objects;

public class AdminAddNewProductActivity extends AppCompatActivity {
    private String CategoryName, Description, Price, saveCurrentDate, saveCurrentTime ,security ,borowingprice;
    public static String Pname;
    private Button AddNewProductButton ;
    private ImageView InputProductImage;
    private EditText InputProductName, InputProductDescription, InputProductPrice,Securityprice,Borrowingprice;
    private static final int GalleryPick = 1;
    private Uri ImageUri;
    private String productRandomKey, downloadImageUrl;
    private StorageReference ProductImagesRef;
    private DatabaseReference ProductsRef;
    private ProgressDialog loadingBar;
String phone;
EditText PHONE;

    @SuppressLint("MissingInflatedId")
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_add_new_product);
        PHONE=findViewById(R.id.number);

        CategoryName = getIntent().getExtras().get("category").toString();
        ProductImagesRef = FirebaseStorage.getInstance().getReference().child("Product Images");
        ProductsRef = FirebaseDatabase.getInstance().getReference().child("Vendors");
        AddNewProductButton = findViewById(R.id.add_new_product);
        InputProductImage = findViewById(R.id.select_product_image);
        InputProductName = findViewById(R.id.product_name);
        InputProductDescription = findViewById(R.id.product_description);
        InputProductPrice = findViewById(R.id.product_price);

        Securityprice= findViewById(R.id.security_price);
        Borrowingprice= findViewById(R.id.borrowing_price);
        loadingBar = new ProgressDialog(this);

        InputProductImage.setOnClickListener(view -> OpenGallery());


        AddNewProductButton.setOnClickListener(view -> ValidateProductData());
    }


    private void OpenGallery(){
        Intent galleryIntent = new Intent();
        galleryIntent.setAction(Intent.ACTION_GET_CONTENT);
        galleryIntent.setType("image/*");
        startActivityForResult(galleryIntent, GalleryPick);
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode==GalleryPick  &&  resultCode==RESULT_OK  &&  data!=null)
        {
            ImageUri = data.getData();
            InputProductImage.setImageURI(ImageUri);
        }
    }
    private void ValidateProductData() {
        Description = InputProductDescription.getText().toString();
        Price = InputProductPrice.getText().toString();
        Pname = InputProductName.getText().toString();
        security=Securityprice.getText().toString();
        borowingprice=Borrowingprice.getText().toString();
        phone=PHONE.getText().toString().trim();
        if (ImageUri == null)
        {
            Toast.makeText(this, "Product image is mandatory...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(Description))
        {
            Toast.makeText(this, "Please write product description...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(Price))
        {
            Toast.makeText(this, "Please write product Price...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(Pname))
        {
            Toast.makeText(this, "Please write product name...", Toast.LENGTH_SHORT).show();
        }else if (TextUtils.isEmpty(security))
        {
            Toast.makeText(this, "Please write Security fees...", Toast.LENGTH_SHORT).show();
        }else if (TextUtils.isEmpty(borowingprice))
        {
            Toast.makeText(this, "Please write Borrowing price...", Toast.LENGTH_SHORT).show();
        }
        else
        {
            StoreProductInformation();
        }

    }
    private void StoreProductInformation()
    {
        loadingBar.setTitle("Add New Product");
        loadingBar.setMessage("Dear Admin, please wait while we are adding the new product.");
        loadingBar.setCanceledOnTouchOutside(false);
        loadingBar.show();

        Calendar calendar = Calendar.getInstance();

        SimpleDateFormat currentDate = new SimpleDateFormat("MMM dd, yyyy");
        saveCurrentDate = currentDate.format(calendar.getTime());

        SimpleDateFormat currentTime = new SimpleDateFormat("HH:mm:ss a");
        saveCurrentTime = currentTime.format(calendar.getTime());

        productRandomKey = saveCurrentDate + saveCurrentTime;


        final StorageReference filePath = ProductImagesRef.child(ImageUri.getLastPathSegment() + productRandomKey + ".jpg");

        final UploadTask uploadTask = filePath.putFile(ImageUri);

        uploadTask.addOnFailureListener(e -> {
            String message = e.toString();
            Toast.makeText(AdminAddNewProductActivity.this, "Error: " + message, Toast.LENGTH_SHORT).show();
            loadingBar.dismiss();
        }).addOnSuccessListener(taskSnapshot -> {
            Toast.makeText(AdminAddNewProductActivity.this, "Product Image uploaded Successfully...", Toast.LENGTH_SHORT).show();
            Task<Uri> urlTask = uploadTask.continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
                @Override
                public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
                    if (!task.isSuccessful())
                    {
                        throw Objects.requireNonNull(task.getException());
                    }

                    downloadImageUrl = filePath.getDownloadUrl().toString();
                    return filePath.getDownloadUrl();
                }
            }).addOnCompleteListener(task -> {
                if (task.isSuccessful())
                {
                    downloadImageUrl = task.getResult().toString();

                    Toast.makeText(AdminAddNewProductActivity.this, "got the Product image Url Successfully...", Toast.LENGTH_SHORT).show();

                    SaveProductInfoToDatabase();
                }
            });
        });

    }
    private void SaveProductInfoToDatabase()
    {
        HashMap<String, Object> productMap = new HashMap<>();
        productMap.put("pid", productRandomKey);
        productMap.put("date", saveCurrentDate);
        productMap.put("time", saveCurrentTime);
        productMap.put("description", Description);
        productMap.put("image", downloadImageUrl);
        productMap.put("category", CategoryName);
        productMap.put("price", Price);
        productMap.put("Borrowing price", borowingprice);
        productMap.put("Security Fees", security);
        productMap.put("pname", Pname);

        ProductsRef.child(phone).child("Products").child(Pname).updateChildren(productMap)
                .addOnCompleteListener(task -> {
                    if (task.isSuccessful())
                    {
                        Intent intent = new Intent(AdminAddNewProductActivity.this, AdminCategoryActivity.class);
                        startActivity(intent);

                        loadingBar.dismiss();
                        Toast.makeText(AdminAddNewProductActivity.this, "Product is added successfully..", Toast.LENGTH_SHORT).show();
                    }
                    else
                    {
                        loadingBar.dismiss();
                        String message = Objects.requireNonNull(task.getException()).toString();
                        Toast.makeText(AdminAddNewProductActivity.this, "Error: " + message, Toast.LENGTH_SHORT).show();
                    }

                });

    }}


    

i am using java and firebase for  MULTIVENDER renting app but its not showing me the products rightly only one product is showing me repeatedly