在list< object>中获取项目的ID；在JSF中 [英] Getting id of item in list<object> in JSF

问题描述

我不知道单击表单按钮时应该使用哪种方法以及如何开始编码以获取特定对象项的id.

I don't have any idea what approach and how I should start coding to get the id of a specific object item when a form button is clicked.

显示的产品ID 值是我创建的产品表的主键.我来自Swing编程，并且在 Swing 中，我可以轻松地使用JLabel.getText();来将产品ID 1,4,5,6显示在屏幕截图中.但是我想 JSF 会有所不同.

The Product Id values showing are primary keys of the product table I created. I'm coming from Swing programming and in Swing I can easily use the JLabel.getText(); to get the product Ids 1,4,5,6 shown on the screenshot. But I guess it's different with JSF.

此外，这些对象值包含在ui:repeat循环中

Also, these object values are contained in a ui:repeat loop

frames.xhtml

<ui:repeat value="#{frameBean.all}" var="f" varStatus="loop">
            <h:outputText escape="false" rendered="#{loop.index % 3 == 0}" />
            <div >
                <div class="col-sm-6 col-md-3">
                    <div class="thumbnail clearfix">
                        <img src="..." alt="frame image placeholder" width="240" height="180"/>
                            <div class="caption">
                                <p>
                                    <h:outputLabel>Product ID: </h:outputLabel>
                                    <h:outputText value="#{f.product_id}"/>
                                </p>
                                <p><h:outputLabel value="#{f.name}"/></p>
                                <p><h:outputText value="#{f.description}"/></p>
                                <p>
                                    <h:panelGroup rendered="#{login.userRole eq 'customer' or login.userRole eq null}">
                                        <a href="#" class="btn btn-primary pull-right" role="button">Add To Cart</a> 
                                    </h:panelGroup>
                                </p>
                            </div>
                    </div>
                </div>
            </div>
            <h:outputText escape="false" rendered="#{loop.last or (loop.index + 1) % 3 == 0}" />
        </ui:repeat>

当然可以使用f.product_Id，但是如果单击添加到购物车按钮，如何获得特定的ID?

Surely, I can use the f.product_Id but how can I get a specific Id if Add To Cart button is clicked?

这是包含getAll()框架方法的实现

Here's the implementation containing the getAll() frames method

public List<Frame> getAll() throws SQLException {
        List<Frame> list = new ArrayList<>();

        PreparedStatement ps = null;
        try {
            String SQL = "select product_id, name, description, price_per_sqft, material from product where isFrame = 1";
            ps = con.prepareStatement(SQL);

            //get customer data from database
            ResultSet result = ps.executeQuery();
            while (result.next()) {
                Frame frame = new Frame();

                frame.setProduct_id(result.getInt("product_id"));
                frame.setName(result.getString("name"));
                frame.setDescription(result.getString("description"));
                frame.setPrice_per_sqft(result.getDouble("price_per_sqft"));
                frame.setMaterial(result.getString("material"));

                //store all data into a List
                list.add(frame);
            }
        } catch (SQLException | HeadlessException e) {
            e.printStackTrace();

        } finally {
            try {
                con.close();
                ps.close();
            } catch (Exception e) {
                e.printStackTrace();

            }
        }

        return list;
    }

为了获得框架的乘积ID，我正在考虑创建一个addToCart(int aProductId)方法.它将需要aProductId参数.

For the purpose of obtaining the product Id of the frame I'm thinking of creating an addToCart(int aProductId) method. It will require aProductId argument.

谢谢.

推荐答案

您可以使用f:param组件存储产品ID

You can use f:param component for store the product id

<p>
    <h:outputLabel>Product ID: </h:outputLabel>
    <h:outputText value="#{f.product_id}"/>
    <f:param name="productId" value=""#{f.product_id}""></f:param>
</p>

然后在bean中，您可以使用FacesContext获取值

and later in the bean you can get the value by using FacesContext

String propertyId = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap()
                .get("productId");

这篇关于在list< object>中获取项目的ID；在JSF中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！