在类com.sale.organiccrops.organiccropsonsale.CartData上找不到要序列化的属性com.google.firebase.database.DatabaseException：

public class CartData {
    public String productId;
    public String productName;
    public int quantity;

    public CartData() {
        // Default constructor required for Firebase
    }

    public CartData(String productId, String productName, int quantity) {
        this.productId = productId;
        this.productName = productName;
        this.quantity = quantity;
    }

    // Getters and setters

    @PropertyName("product_id")
    public String getProductId() {
        return productId;
    }

    @PropertyName("product_id")
    public void setProductId(String productId) {
        this.productId = productId;
    }

    @PropertyName("product_name")
    public String getProductName() {
        return productName;
    }

    @PropertyName("product_name")
    public void setProductName(String productName) {
        this.productName = productName;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }
}