如何使用Thymeleaf发布实体类型数据列表？

Question

我的项目基于springboot、Thymeleaf、mysql、html和Jquery。

场景我的场景是使用Thyemeleaf并点击Spring boot@RestController发布EntSetCharges数据列表。以前我处理过这个错误错误错误1：错误2：现在又出现了一个错误

2017-11-22 14:58:19.717错误1420---[nio-8080-exec-1]o. a. c. c.C.[.[.]Servlet.service（）的servlet[调度Servlet]在上下文中与路径[]抛出异常[请求处理失败；嵌套异常是org.thymeleaf.exceptions.TemplateProcessingExc0019：异常评估SpringEL表达式："temEntSetChargesList[0]. chargesName"（模板："SetCharges"-行37， col91）]与根本原因org.springframework.expression.spel.SpelEvalue ationExc0019： EL1025E：集合有'0'元素，索引'0'无效

该行表示HTML代码是表的第一列

th： field="*{temEntSetChargesList[__${status.index}__]. chargesName}"

我仍然无法将数据发布到控制器。。请帮帮我。。

<form id="setchargesformid" method="post" th:object="${wrpSetCharges}" th:action="@{/updatesetcharges}">
	<div class="table-responsive"> 
	
	<table class="table table-hover">
	<thead>
	    <tr>
      <th>Charge Name</th>
      <th>Amount</th>
      <th>Charge/Unit Type</th>
    </tr>
    </thead>
    
    <tbody>
    <tr th:each="savedcharges,status:${savedchargeslist}">
     <!--  <td id="colhide" hidden="true">
      <label th:value="${savedcharges.pkSetCharges}" th:field="*{pkSetCharges}" ></label>
      </td> -->
      
      <td>
      <label th:text="${savedcharges.chargesName}" th:value="${savedcharges.chargesName}" th:field="*{tempEntSetChargesList[__${status.index}__].chargesName}"></label>
      </td>
      
      <td>
      <input id="amt1" class="form-control" th:field="*{tempUnitAmount}">
      </td>
      
      <td>
		<select id="societyname" class="form-control" th:field="*{tempunitType}" >
		<option value="perFlat" selected="selected">perFlat</option>
		<option value="perUnit">perUnit</option>
		<option value="perSqrft">perSqrft</option>
		</select>
      </td>
    </tr>
    </tbody>
    
	</table>
	</div>
	
	<button type="submit" class="btn btn-info">Submit</button>
	<button type="reset" class="btn btn-warn">Reset</button>
	</form>

@RestController

@GetMapping(value="/setchargeslist")
    public ModelAndView doGetSetchargesList()
    {
        List<EntSetCharges> listCharges = new ArrayList<>();
        ModelAndView respondResult = new ModelAndView("SetCharges");
        try {
            /*Get the set charges list*/
            listCharges = serSetCharges.doGetSetChargesList();
            if(listCharges!=null)
            {
            respondResult.addObject("savedchargeslist",listCharges);
            //respondResult.addObject("tempEntSetChargesList",new EntSetCharges());
            respondResult.addObject("wrpSetCharges",new WrpSetCharges());
            }
            else
            {
                respondResult.addObject("savedchargeslist",new ArrayList<>());
            }

        } catch (Exception e) {
            // TODO: handle exception
        }
        return respondResult;
    }

单击Submit按钮时，将点击to/updatesetcharges

@PostMapping(value="/updatesetcharges")
public ModelAndView doUpdateSetCharges(@ModelAttribute WrpSetCharges wrpSetCharges)
{
    ModelAndView respondResult = new ModelAndView();
    try {
        List<EntSetCharges> entSetChargesList = new ArrayList<>();
    Boolean result = serSetCharges.doUpdateSetCharges(entSetChargesList);
} catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
        return respondResult;
    }

这是一个包装类

 public class WrpSetCharges {

        private List<EntSetCharges> tempEntSetChargesList = new ArrayList<>();

        public List<EntSetCharges> getTempEntSetChargesList() {
            return tempEntSetChargesList;
        }

        public void setTempEntSetChargesList(List<EntSetCharges> tempEntSetChargesList) {
            this.tempEntSetChargesList = tempEntSetChargesList;
        }
      }

Answer 1

如评论中所述：异常的原因是

“org.springframework.expression.spel.SpelEvaluationException‌​: EL1025E：（位置10）：集合具有“0”元素，索引“0”无效

只要在团队中添加th:if条件即可。用户可以有零个元素。