Spring - java.lang.NumberFormatException：对于输入字符串

我正在尝试使用 DTO 获取用户及其关联对象的列表。到目前为止，还有一个错误。

Model

 public class UserEntity 
    @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="setter")
    private Set<Module> sModule = new HashSet<Module>();

    @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="checker")
    private Set<Module> cModule = new HashSet<Module>(); 
     //getters and setters

DTO

   public class UserEntityDTO {

private List<Module> sModule = new ArrayList<Module>();
private List<Module> cModule = new ArrayList<Module>();

控制器

   @RequestMapping(value = "/main/user/testing", method = RequestMethod.GET)
    public String getRecords(Model model) {

          List<UserEntity> users = userService.getUserEntity();

      List<UserEntityDTO> usersDTO = new ArrayList<UserEntityDTO>();

      for (UserEntity user: users) {
       UserEntityDTO dto = new UserEntityDTO();

      dto.setUserId(user.getUserId());
      dto.setName(user.getName());
      dto.setsModule(moduleService.getSetterModules(user.getUserId()));
      dto.setcModule(moduleService.getCheckerModules(user.getUserId()));

      usersDTO.add(dto);
     }
      model.addAttribute("users", usersDTO);


  return "/main/user/testing";
 }

JSP page

   <table>
        <tr>
            <th>User Id</th>
                    <th>User Name</th>
                    <th>Module</th>
              </tr>
        <c:forEach items="${users}" var="setter" >
             <c:forEach items="${users.sModule}" var="module" >
            <tr>
                <td><c:out value="${setter.userId}" escapeXml="true" /></td>
                <td><c:out value="${setter.name}" escapeXml="true" /></td>


                <td><c:out value="${module.moduleCode}" escapeXml="true" /></td>
                <td><c:out value="${module.moduleName}" escapeXml="true" /></td>
                <td><c:out value="${module.moduleStatus}" escapeXml="true" /></td>

            </tr>
            </c:forEach>
        </c:forEach>
    </table>

堆栈跟踪

    java.lang.NumberFormatException: For input string: "sModule"
java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
java.lang.Integer.parseInt(Integer.java:492)
java.lang.Integer.parseInt(Integer.java:527)
javax.el.ListELResolver.coerce(ListELResolver.java:173)
javax.el.ListELResolver.getValue(ListELResolver.java:52)
org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:104)
org.apache.el.parser.AstValue.getValue(AstValue.java:183)
org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:185)
org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:106)
org.apache.jsp.WEB_002dINF.views.main.user.testing_jsp._jspx_meth_c_005fforEach_005f1(testing_jsp.java:204)
org.apache.jsp.WEB_002dINF.views.main.user.testing_jsp._jspx_meth_c_005fforEach_005f0(testing_jsp.java:172)
org.apache.jsp.WEB_002dINF.views.main.user.testing_jsp._jspService(testing_jsp.java:111)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:264)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1208)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:992)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:939)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:915)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:811)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:796)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:183)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.access.channel.ChannelProcessingFilter.doFilter(ChannelProcessingFilter.java:144)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)

它在我想要检索的子对象上发生异常。我怎样才能确保我想要得到的字段可以被接受。

您以错误的方式访问 jsp 中的模块。

This:

<c:forEach items="${users}" var="setter" >
    <c:forEach items="${users.sModule}" var="module" >

尝试访问sModule成员users，并且自从users是它尝试转换的列表sModule为整数并将其用作索引。

大概应该是：

<c:forEach items="${users}" var="user" >
    <c:forEach items="${user.sModule}" var="module" >