Question

我有一个Expense类，它有一个ExpenseType类型的字段expenseType。我想在视图页面上显示Expense和ExpenseType类的所有字段。我用每个标签显示ExpenseType中的所有字段，因为它是Expense类中的列表。但是这些字段没有在视图页面上呈现。

在下面的代码中，不显示每个标签内的标签名称和价格。我尝试使用放置在foreach标签旁边的c：out标签显示一些值，但它从未显示，这意味着它在c：forEach

失败

这是我的jsp代码：

    <form:form method="POST" modelAttribute="expenses" action="saveExpense">
          <div class="box-body">
                <div class="form-group col-xs-6 text-spacing">
                      <label>Expense Date</label>
                     <form:input path="date" id="expenseDate" class="form-control"/>
                     <form:errors path="date" cssClass="error" />
                    </div>
                <div class="form-group col-xs-6 text-spacing">
                  <label>Shop/Dealer Name</label>
                  <form:input path="shopName" type="text" class="form-control" placeholder="dealer name"/>
                  <form:errors path="shopName" cssClass="error" />
                </div>
                <div class="container">
                    <div class="row">
                        <div class="col-md-12">
                            <div data-role="dynamic-fields">
                                <div class="form-inline">
                                 <c:forEach items="${expenses.expensesType}" varStatus="status">
                                     <div class="form-group">
                                        <label class="sr-only" for="field-name">Name</label>
                                        <form:input path="expensesType[${status.index}].name" type="text"/>
                                    </div>
                                    <span>-</span>
                                    <div class="form-group">
                                        <label class="sr-only" for="field-value">Price</label>
                                         <form:input path="expensesType[${status.index}].price" type="text"/>
                                    </div>
                                    <button class="btn btn-danger" data-role="remove">
                                        <span class="glyphicon glyphicon-remove"></span>
                                    </button>
                                    <button class="btn btn-primary" data-role="add">
                                        <span class="glyphicon glyphicon-plus"></span>
                                    </button>
                                 </c:forEach>
                                </div>  
                            </div> 
                        </div> 
                    </div>
                </div>
            </div>
          <div class="box-footer">
            <button type="submit" class="btn btn-primary">Save</button>
             <a class="btn btn-primary" href="<c:url value='expensesList'/>"> Cancel </a>
          </div>
      </form:form>

我的控制器：

    @RequestMapping(value = "/expensesForm", method = RequestMethod.GET)
    public String getForm(Model model) {
        model.addAttribute("expenses", new Expenses());
        return "expensesForm";
    }

    @RequestMapping(value = "/saveExpense", method = RequestMethod.POST)
    public String saveCattleDetails(@Valid @ModelAttribute("expenses") Expenses expenses, BindingResult bindingResult,
            Model model) {
        if (bindingResult.hasErrors()) {
            return "expensesForm";
        }
        expensesService.add(expenses);
        return "redirect:expensesList";
    }

模型类

public class Expenses implements Serializable {

    private static final long serialVersionUID = 668608674926007321L;

    @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    @Column(name = "EXPENSES_ID", unique = true)
    private String id;

    @NotNull
    @Column(name = "DATE")
    private Date date;

    @Column(name = "SHOP_NAME")
    private String shopName;

    @Column(name = "TOTAL_EXPENSE")
    private String totalExpenses;

    @Column(name = "DESCRIPTION")
    private String description;

    @OneToMany(mappedBy = "expenses", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private List<ExpensesType> expensesType;

和

@Entity
@Table(name = "EXPENSES_TYPE")
public class ExpensesType implements Serializable {

    private static final long serialVersionUID = 3002107481242774411L;

    @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    @Column(name = "EXPENSE_TYPE_ID", unique = true)
    private String id;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "EXPENSES_ID")
    private Expenses expenses;

    @Column(name = "NAME")
    private String name;

    @Column(name = "CATEGORY")
    private CategoryType category;

    @Column(name = "PRICE")
    private String price;

这些字段未显示的可能错误是什么。

Answer 1

在模型中添加属性时，即

  model.addAttribute("expenses", new Expenses());

您尚未设置Bean费用的expenseType字段，您只需使用新的费用（）。

而是尝试将字段expenseType初始化为新的ArrayList（）。即

Expenses exp = new Expenses();
exp.setExpensesType(new ArrayList());
model.addAttribute("expenses", exp);

在spring中循环JSTL表单标记内的列表

1 个答案: