java - Spring 网络流: Understanding generated JSP

Question

这是为正在制作披萨的用户生成的 JSP 文件，它是另一个流程的子流程。我不明白为什么我需要选中至少一个复选框才能使提交按钮起作用。 我的意思是，当选中 0 个复选框时，提交按钮会将我带回同一站点。我希望我带来了足够的信息，如果还有什么我应该添加的，请写下来。

这个编码在哪里？在 JSP 中或流文件中的某个位置？

Updated with required class.

I made github repo of my project.

createPizza.jspx

<div xmlns:form="http://www.springframework.org/tags/form"
     xmlns:jsp="http://java.sun.com/JSP/Page">

  <jsp:output omit-xml-declaration="yes"/>  
  <jsp:directive.page contentType="text/html;charset=UTF-8" />  

    <h2>Create Pizza</h2>
    <form:form commandName="pizza">
      <input type="hidden" name="_flowExecutionKey" 
          value="${flowExecutionKey}"/>
    
      <b>Size: </b><br/>

  <form:radiobutton path="size" 
                    label="Small (12-inch)" value="SMALL"/><br/>
  <form:radiobutton path="size" 
                    label="Medium (14-inch)" value="MEDIUM"/><br/>
  <form:radiobutton path="size"
                    label="Large (16-inch)" value="LARGE"/><br/>
  <form:radiobutton path="size" 
                    label="Ginormous (20-inch)" value="GINORMOUS"/>
      <br/>
      <br/>
      
      <b>Toppings: </b><br/>
      <form:checkboxes path="toppings" items="${toppingsList}" 
                       delimiter="&lt;br/&gt;"/><br/><br/>

          
      <input type="submit" class="button" name="_eventId_addPizza" value="Continue"/>
      
      <input type="submit" class="button" name="_eventId_cancel" value="Cancel"/>          
    </form:form>
</div>

order-flow.xml

<?xml version="1.0" encoding="UTF-8"?>
<flow xmlns="http://www.springframework.org/schema/webflow"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.springframework.org/schema/webflow 
  http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd">

  <input name="order" required="true" />
  
  <view-state id="showOrder">
    <transition on="createPizza" to="createPizza" />
    <transition on="checkout" to="orderCreated" />
    <transition on="cancel" to="cancel" />
  </view-state>
  

  <!-- Corresponding state -->
  <view-state id="createPizza" model="flowScope.pizza">
  
    <on-entry>
      <set name="flowScope.pizza" 
          value="new com.springinaction.pizza.domain.Pizza()" />

      <evaluate result="viewScope.toppingsList"  expression=
                   "T(com.springinaction.pizza.domain.Topping).asList()" />
    </on-entry>
    
    <transition on="addPizza" to="showOrder">
      <evaluate expression="order.addPizza(flowScope.pizza)" />
    </transition>
    
    <transition on="cancel" to="showOrder" />
  </view-state>
  
  <end-state id="cancel" />
  <end-state id="orderCreated" />
</flow>

Pizza.java

package com.springinaction.pizza.domain;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

@SuppressWarnings("serial")
public class Pizza implements Serializable {
  private PizzaSize size;
  private List<Topping> toppings;
  
  public Pizza() {
    toppings = new ArrayList<Topping>();
    size = PizzaSize.LARGE;
  }

  public PizzaSize getSize() {
    return size;
  }

  public void setSize(PizzaSize size) {
    this.size = size;
  }
  
  public void setSize(String sizeString) {
    this.size = PizzaSize.valueOf(sizeString);
  }

  public List<Topping> getToppings() {
    return toppings;
  }

  public void setToppings(List<Topping> toppings) {
    this.toppings = toppings;
  }
  
  public void setToppings(String[] toppingStrings) {
    for (int i = 0; i < toppingStrings.length; i++) {
      toppings.add(Topping.valueOf(toppingStrings[i]));
    }
  }
}

Answer 1

显然，正如 shazin 所强调的，问题在于 Pizza 类中重载的 setToppings 方法，这会带来麻烦。在注释以字符串数组作为参数的那个之后，应用程序可以正常工作。可能它与 EL 有关，EL 以这种方式处理它，并且可能在另一个容器上发生变化(我使用 tomcat，我认为专用服务器是 Jetty)。