【问题标题】:Adding same objects into TableView more than once at different times在不同时间多次将相同的对象添加到 TableView 中
【发布时间】:2019-01-19 11:18:18
【问题描述】:

我正在尝试构建一个购物项目。该程序可以毫无问题地将所有添加的产品保存在 SQLite 数据库中。

有一些限制。

产品可以是主要产品或标准产品。主要产品有自己的子产品。如果客户想购买主产品,那么客户也必须购买它的子产品。

到目前为止,一切似乎都还不错。在 mainScreen 中,我在顶部用户上构建了 2 个 tableview,可以看到所有产品的列表(tableProductsInfo),在表格下方,您可以看到购物车表(tableShoppingBasket)。

如果用户从 tableProductsInfo 中选择一个产品并点击添加到购物车按钮,该产品将被添加到下面和图片中的 shoppingBasket(observableList) 上。

这里是我的添加到购物车按钮代码

@FXML
public void addtoShoppingBasket() throws IOException {

    if(tableProductInfo.getSelectionModel().getSelectedItem()!=null){ // eğer bir ürün seçiliyse // if any product selected?
        Product selectedItem = (Product) tableProductInfo.getSelectionModel().getSelectedItem(); //
        int inputQuantity = getInputDialogPane(); // Kaç tane ürün eklenmek istiyor? // how many products user wants to buy?
        if(selectedItem.getStock()>=inputQuantity){ // STOK KONTROL eğer eklenmek istenen ürün stokta varsa // Checking stock if its avaliable for selling
            selectedItem.setQuantity(inputQuantity);

            //main ürün şuan alınabilir durumda (sub ürünü varsa henüz değil)

            if (selectedItem.getSubProduct()==1){ // eğer sub ürünü varsa // if selected product has subProducts
                //that means its main product and we need to check its sub products

                //1)sub ürün listesini al, // get all subProducts of selectedItem
                //2) sub ürün stok kontrollerini yap main.Quantity*sub.Quantity <= Sub.stock // check its stock
                //3) eğer stokta varsa tabloya ekle yoksa uyarı ver // if any of subitems out of stock capasity then don't let user to buy the main product and its subProducts
                ProductDialogPaneController productDialogPaneController = new ProductDialogPaneController();
                ObservableList returnedList =FXCollections.observableArrayList();
                returnedList=productDialogPaneController.getSubProducts(selectedItem.getProductID()); // getting all subproducts of main Product


                Iterator<Product> productIterator = returnedList.iterator();
                boolean inStock=true;
                while (productIterator.hasNext()){
                    Product currentSubProduct = productIterator.next();

                if((currentSubProduct.getQuantity()*selectedItem.getQuantity())>currentSubProduct.getStock()){
                    //eğer eklenmek istenen alt ürünün tanımlanan Miktarı*Alınmak istenen Main ürünün miktarı stok kapasitesinden fazla değilse
                    //sub products should multiply with main product quantity
                    inStock=false;
                }

                }
                if(inStock==true){
                    System.out.println("in stock true");

                    // there is no stock problem for any sub product
                    //here we need to check if shoppingBasket contains selected item or its sub products

                    //if it contains then update/change its quantity
                    //else then add selected item and its subProducts into shoppingBasket






                    shoppingBasket.add(selectedItem);
                    shoppingBasket.addAll(returnedList);

                }else{
                    System.out.println("ALMAK İSTEDİĞİNİZ MAİN ÜRÜNLE BİRLİKTE ALINMASI GEREKEN ALT ÜRÜNLERDEN BİRİ VEYA BİRKAÇI STOKTA YOK!");
                }



            }else{ //eğer sub ürünü yoksa (selectedItem.getSubProduct==0)
                //if it's not the main product in another words if its standard Product

                shoppingBasket.add(selectedItem);

            }

        }else{
            System.out.println("ALMAK İSTEDİĞİNİZ MAİN ÜRÜN STOKTA YETERİ KADAR YOK");
            //the product you wanted to buy is out of stock capacity
        }




    }else{ // eğer ürün listesinden bir ürün seçilmediyse
        System.out.println("ALIŞ VERİŞ SEPETİNE EKLENECEK ÜRÜNÜ SEÇMEDİNİZ !");
        //no item selected to buy
    }

}

我像这样将我的产品放入购物桌;

@FXML
public void initialize(){
tableShoppingBasket.setItems(shoppingBasket);
}

我的问题

tableShoppingBasket 清空时;

如果我想第一次添加主产品! 似乎没有问题。 您可以在这里看到主屏幕:

但是当我想添加相同的产品时第二次 有问题,我的表好像是这样的

我不想在不同的行中列出相同的产品。

如果之前添加了这个产品,我想更新它的数量。(oldProduct.getQuantity+newProduct.getQuantity)

我需要修复这个视图:

我想更新它的数量并看到像这样的表格行

标签名称价格数量

  • 主mProduct 200 2
  • 子产品X 10 2
  • 子产品 50 2

我尝试使用此代码解决我的问题,但它没有按我的意愿工作。 我的意思是它没有添加所选主产品的子产品。

  //checking for MAIN PRODUCT
                    if(shoppingBasket.contains(selectedItem)){

                     int index= shoppingBasket.indexOf(selectedItem);
                        Product existingItem=shoppingBasket.get(index);
                        shoppingBasket.remove(selectedItem); //removing old item
                        existingItem.setQuantity(existingItem.getQuantity()+inputQuantity);
                     shoppingBasket.add(index,existingItem); // adding updated item
                    }else{
                        shoppingBasket.add(selectedItem); // if if its adding first time
                    }

                    //Checking for Sub Products



                    Iterator subItemIterator=returnedList.iterator();
                    while (subItemIterator.hasNext()){
                        Product newSubItem = (Product) subItemIterator.next();
                        Iterator ShoppingIterator = shoppingBasket.iterator();
                        if(shoppingBasket!=null && !shoppingBasket.isEmpty()){
                        while (ShoppingIterator.hasNext()){
                            Product oldSubItem= (Product) ShoppingIterator.next();
                            if(oldSubItem.getProductID()==newSubItem.getProductID()){
                                oldSubItem.setQuantity(newSubItem.getQuantity()+oldSubItem.getQuantity());
                            }else{
                                shoppingBasket.add(newSubItem);
                            }
                        }
                        } else {shoppingBasket.add(newSubItem);
                                                        }
                    }

线程“JavaFX 应用程序线程”java.lang.RuntimeException 中的异常:java.lang.reflect.InvocationTargetException 引起:java.util.ConcurrentModificationException

【问题讨论】:

  • 目前还不清楚你在问什么。确切的问题是什么?链接到外部屏幕截图并不能说明问题所在。附带说明,请不要发布指向外部屏幕截图的链接;如有必要,将图片嵌入您的帖子中。
  • 您可以看到我将文本样式设置为 bold 的问题。但让我再澄清一次。当用户在不同时间将相同产品添加到购物车中时,我想更新购物桌视图
  • “我试图像这样更新 shoppingBasket(observableList) 上的产品数量,但它没有按我的意愿工作。”该代码在我看来(大部分)是正确的。 “没有按我的意愿工作”是什么意思?该代码的具体结果是什么?
  • 看来你需要做类似的事情。 if(checkouttable.contains(item){//Increment item quanity}else{//add new Item}.
  • 为什么要删除旧产品?为什么不只是提高他们的质量?

标签: java javafx tableview javafx-8


【解决方案1】:

我刚刚解决了我的问题。我发现了我的一些错误,如果你愿意,你可以找到我的运行代码。

我最大的错误之一

shoppingBasket.contains(selectedItem);

如果数量不同,则不会返回正确的项目。

我通过在 shoppingBasket 上使用迭代器并比较产品 ID 解决了我的这个问题

@FXML public void addtoShoppingBasket() 抛出 IOException {

    if(tableProductInfo.getSelectionModel().getSelectedItem()!=null){ // eğer bir ürün seçiliyse // if any product selected?
        Product selectedItem = (Product) tableProductInfo.getSelectionModel().getSelectedItem(); //
        int inputQuantity = getInputDialogPane(); // Kaç tane ürün eklenmek istiyor? // how many products user wants to buy?
        int totalQ=returnTotalQuantity(selectedItem); // if this item added already in the shopping basket we are subsraction added quantity

        if(selectedItem.getStock()-totalQ>=inputQuantity){ // STOK KONTROL eğer eklenmek istenen ürün stokta varsa // Checking stock if its avaliable for selling
            //selectedItem.setQuantity(inputQuantity);

            if (selectedItem.getSubProduct()==1){ // eğer sub ürünü varsa // if selected product has subProducts
                //that means its main product and we need to check its sub products

                //1)sub ürün listesini al, // get all subProducts of selectedItem
                //2) sub ürün stok kontrollerini yap main.Quantity*sub.Quantity <= Sub.stock // check its stock
                //3) eğer stokta varsa tabloya ekle yoksa uyarı ver // if any of subitems out of stock capasity then don't let user to buy the main product and its subProducts
                ProductDialogPaneController productDialogPaneController = new ProductDialogPaneController();
                ObservableList returnedList =FXCollections.observableArrayList();
                returnedList=productDialogPaneController.getSubProducts(selectedItem.getProductID()); // getting all subproducts of main Product


                Iterator<Product> productIterator = returnedList.iterator();
                boolean inStock=true;
                while (productIterator.hasNext()){
                    Product currentSubProduct = productIterator.next();
                    int totalSubQ=returnTotalQuantity(currentSubProduct);
                if((currentSubProduct.getQuantity()*inputQuantity)>currentSubProduct.getStock()-totalSubQ){
                    //eğer eklenmek istenen alt ürünün tanımlanan Miktarı*Alınmak istenen Main ürünün miktarı stok kapasitesinden fazla değilse
                    //sub products should multiply with main product quantity
                    inStock=false;
                }

                }
                if(inStock==true){
                    if(shoppingBasket!=null && !shoppingBasket.isEmpty()){
                    Iterator mainIterator=shoppingBasket.iterator();
                    while (mainIterator.hasNext()){
                        Product oldMain= (Product) mainIterator.next();
                        if(oldMain.getProductID()==selectedItem.getProductID()){
                            oldMain.setQuantity(oldMain.getQuantity()+inputQuantity);
                        }
                    }
                        Iterator subItemIterator=returnedList.iterator();
                    while (subItemIterator.hasNext()){
                        Product newSubItem = (Product) subItemIterator.next();
                        Iterator ShoppingIterator = shoppingBasket.iterator();
                        while (ShoppingIterator.hasNext()){
                            Product oldSubItem= (Product) ShoppingIterator.next();
                            if(oldSubItem.getProductID()==newSubItem.getProductID() && oldSubItem.getSubProduct()!=1){
                                oldSubItem.setQuantity((newSubItem.getQuantity()*inputQuantity)+oldSubItem.getQuantity());
                                calculateTotalPriceofShoppingBasket();
                            }
                        }
                        }
                            }else{
                        selectedItem.setQuantity(inputQuantity);
                        shoppingBasket.add(selectedItem);
                        // we should multiply subItem Quantity with new InputQuantity
                       Iterator iterator = returnedList.iterator();
                       while (iterator.hasNext()){
                           Product newQforSubItem= (Product) iterator.next();
                           newQforSubItem.setQuantity(inputQuantity*newQforSubItem.getQuantity());
                       }
                        shoppingBasket.addAll(returnedList);
                    }

                }else{
                    System.out.println("ALMAK İSTEDİĞİNİZ MAİN ÜRÜNLE BİRLİKTE ALINMASI GEREKEN ALT ÜRÜNLERDEN BİRİ VEYA BİRKAÇI STOKTA YOK!");
                            //one of sub product out of its stock capacity
                }
            }else{ //eğer sub ürünü yoksa (selectedItem.getSubProduct==0)
                //if its not main product in other word if its standart Product
                selectedItem.setQuantity(inputQuantity);
                Iterator standartProduct = shoppingBasket.iterator();
                if(!shoppingBasket.isEmpty()&&shoppingBasket!=null) {
                    while (standartProduct.hasNext()) {
                        Product standart = (Product) standartProduct.next();
                        if (standart.getProductID() == selectedItem.getProductID()) {
                            standart.setQuantity(standart.getQuantity() + inputQuantity);
                            calculateTotalPriceofShoppingBasket();
                        }
                    }
                }else { // shoppingbasket is empty
                    selectedItem.setQuantity(inputQuantity);
                    shoppingBasket.add(selectedItem);
                }
            }

        }else{
            System.out.println("ALMAK İSTEDİĞİNİZ MAİN ÜRÜN STOKTA YETERİ KADAR YOK");
            //the product you wanted to buy is out of stock capacity
        }




    }else{ // eğer ürün listesinden bir ürün seçilmediyse
        System.out.println("ALIŞ VERİŞ SEPETİNE EKLENECEK ÜRÜNÜ SEÇMEDİNİZ !");
        //no item selected to buy
    }

}

【讨论】:

  • 您始终可以在您的Product 类中创建自己的equals()hashcode() 方法来比较ID,而不是使用循环。那么contains()方法仍然可以使用。
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