java - 玩2模板如何访问列表类型的实体成员

Question

我的实体是:UserShoppingList、产品和类别，如下所示:

package models;

import java.util.*;

import play.db.ebean.*;
import play.data.validation.Validation;
import play.data.validation.Constraints.*;

import javax.persistence.*;

import com.avaje.ebean.Ebean;

/**
 * Entity managed by Ebean
 */


@Entity
public class UserShoppingList extends Model{

      @Id
      public Long id;

      @Required
      public String listName;

      @ManyToOne
      public User user;

      @ManyToMany
      public List<Product> products = new ArrayList<Product>();

      //getters and setters

//(I have included them, not shown here)

package models;

import java.util.*;

import play.db.ebean.*;
import play.data.validation.Constraints.*;
import javax.persistence.*;

/**
 * Product entity managed by Ebean
 */

@Entity
public class Product extends Model{
     @Id
     public Long Id;

     @ManyToOne
     public Category category;

     @Required
     public String brandName;

     @Required
     public String productName;


    // -- Queries

     public static Model.Finder<Long,Product> find = new Model.Finder(Long.class, Product.class);

package models;

import java.util.List;

import javax.persistence.*;

import play.db.ebean.*;
import play.data.validation.*;
import play.db.jpa.*;

/**
 * Category entity managed by JPA
 */
@Entity 

public class Category {
     @Id
     public Long id;


     @Constraints.Required
     public String categoryName;

     // --getters and setters

我的模板:

@(shoppinglist: List[models.Product], categorylist: List[Category], 
userShoppingListsForm: Form[models.UserShoppingList])

@import helper._


@main("Shopping list products") {

    var productlist = shoppinglist.getProducts()

    <h1>Shopping List</h1>


    @for(c <- categorylist){

    <ul>

            <li class = "categoryrow">@categorylist.getCategoryName()</li>



            @for(p <- productlist) {


            <ul>
                <li class="productcolumn">  
                    @p.getBrandName()
                </li>

                <li class="productcolumn">  
                    @p.getProductName()
                </li>               

                <li class="command">
                    id = @p.getId()!
                    @form(routes.ShoppingLists.deleteProduct(id)) {
                    <input type="submit" value="Delete">
                    }
                </li>

            </ul>

            }



        </ul>

        }



        <h2>Add a product to list</h2>

        @form(routes.ShoppingLists.newUserShoppingList()) {

            @inputText(userShoppingListsForm("listName")) 

            <input type="submit" value="Create">

        }



}

我收到以下错误:

value getCategoryName is not a member of java.util.List[models.Category]

有人可以建议我更好的方法来为基于 java 的 Play 2 框架创建模板来访问列表本身的实体成员(例如:“UserShoppingList”中的产品吗？

非常感谢任何帮助。谢谢一百万

Answer 1

您想要对列表元素使用 getter，但您试图在整个 List 上使用它

这可能是正确的解决方案:

<li class = "categoryrow">@c.getCategoryName()</li>