ViewNote

public class ViewProduct extends AppCompatActivity {

    private String edit_product_ID;
    //private String edit_product_Product;
    private String edit_product_Price;

    private EditText productView, priceView;
    private TextView mSave, mDelete;
    private FirebaseFirestore db = FirebaseFirestore.getInstance();

    private static final String KEY_PRODUCT = "product";
    private static final String KEY_PRICE = "price";

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

        Intent intent = getIntent();
        String product;
        String price;
        String id;

        id = String.valueOf(getIntent().getExtras().get("Id"));
        product = String.valueOf(getIntent().getExtras().get("Product"));
        price = String.valueOf(getIntent().getExtras().get("Price"));

        Toast.makeText(this, "The Product ID: " + id +
                " Product Name " + product + " Product Price " + price, Toast.LENGTH_LONG).show();

        EditText productView = findViewById(R.id.product);
        productView.setText(product);
        EditText priceView = findViewById(R.id.price);
        priceView.setText(price);
        mSave = (TextView) findViewById(R.id.save);
        mDelete = (TextView) findViewById(R.id.delete);

    }

    public void saveProduct(View view) {
        String product = productView.getText().toString();
        String price = priceView.getText().toString();

        Map<String, Object> product_update = new HashMap<>();
        product_update.put(KEY_PRODUCT, product);
        product_update.put(KEY_PRICE, price);

        db.collection("ultra_liquors").document().set(product_update)
                .addOnSuccessListener(new OnSuccessListener<Void>() {
                    @Override
                    public void onSuccess(Void aVoid) {
                        Toast.makeText(ViewProduct.this, "Product saved", Toast.LENGTH_SHORT).show();
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        Toast.makeText(ViewProduct.this, "Not saved", Toast.LENGTH_SHORT).show();
                    }
                });
    }
}