数据模型必须在启用选择时实现

Question

我想在选中复选框并按下删除按钮时从数据表中删除行。。

这是数据表片段：

<p:dataTable id="cartTable" lazy="true" scrollable="true"
             scrollHeight="115" selection="#{Cart_Check.selectedItems}"
             value="#{Cart_Check.cart}" var="cart" rowKey="#{cart.sheetno}"
             style="widht:100%;margin-top:10%;margin-left:1%;margin-right:30px ;box-shadow: 10px 10px 25px #888888;">
    <f:facet name="header">  
        Checkbox Based Selection  
    </f:facet>
    <p:column selectionMode="multiple" style="width:2%">
    </p:column>
    //Here the columns are metion
    <f:facet name="footer">
        <p:commandButton id="viewButton" value="Remove" />
    </f:facet>
</p:dataTable>

这是支持豆

public class checkcart {
        private int items;
        private ArrayList<User_Cart> cart;
        private ArrayList<User_Cart> selectedItems;
    public checkcart() {
        getvalues();
    }
//getter and setter 
    public void getvalues() {
        FacesContext context = FacesContext.getCurrentInstance();
        HttpSession session = (HttpSession) context.getExternalContext()
                .getSession(false);
        System.out.println("Cart Request ::::" + session.getAttribute("regid"));
        try {
            Connection connection = BO_Connector.getConnection();
            String sql = "Select * from cart_orderinfo where usrregno=?";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1, (String) session.getAttribute("regid"));
            ResultSet rs = ps.executeQuery();
            cart = new ArrayList<>();
            while (rs.next()) {
                User_Cart user_cart = new User_Cart();
                user_cart.setSheetno(rs.getString("sheetno"));
                user_cart.setState_cd(rs.getString("state_cd"));
                user_cart.setDist_cd(rs.getString("dist_cd"));
                user_cart.setLicensetype(rs.getString("license_type"));
                user_cart.setFormat(rs.getString("sheet_format"));
                user_cart.setQuantity(rs.getInt("quantity"));
                cart.add(user_cart);
            }
        } catch (Exception ex) {
            System.out.println(ex);
        }
    }
}

当我运行这个页面时，我会得到以下错误启用选择时，数据模型必须实现org.timefaces.model.selectabledatamodel

但当我删除复选框时，他们没有错误，但没有复选框。

该怎么办以及如何解决以下错误。。请帮忙。。

我想要这样的东西：http://www.primefaces.org/showcase/ui/datatableRowSelectionRadioCheckbox.jsf

Answer 1

您只需要定义ListDataModel，如下所示，

public class SD_User_Cart extends ListDataModel<User_Cart> implements SelectableDataModel<User_Cart> {
    public SD_User_Cart() {
    }
    public SD_User_Cart(List<User_Cart> data) {
        super(data);
    }
    @Override
    public User_Cart getRowData(String rowKey) {
        //In a real app, a more efficient way like a query by rowKey should be implemented to deal with huge data  
        List<User_Cart> rows = (List<User_Cart>) getWrappedData();
        for (User_Cart row : rows) {
            if (row.getCartId.toString().equals(rowKey)) {//CartId is the primary key of your User_Cart
                return row;
            }
        }
        return null;
    }
    @Override
    public Object getRowKey(User_Cart row) {
        return row.get.getCartId();
    }
}

将您的"购物车"对象更改为SD_User_cart，如下所示，

private SD_User_Cart cart;

然后在p:datatable中定义选择，并添加一列，如下所示，

<p:column selectionMode="multiple" style="width:18px"/>

希望这有帮助：）

Answer 2

您需要在像private User_Cart[] selectedItems;这样的后类public class checkcart中定义一个private ArrayList<User_Cart> selectedItems;数据成员，并为其提供setter和getter方法。我也遇到过同样的问题。