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

Question

我想要使用DTO获取用户及其关联对象的列表。到目前为止有一个错误。

型号

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页面

<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) 

它正在我想要检索的子对象发生异常。我怎样才能确保我想获得的领域能被接受。

Answer 1

您正在以错误的方式访问jsp中的模块。

此：

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

试图访问的userssModule构件，并且由于users是一个列表它试图转换sModule整数和使用，作为一个索引。

这也许应该是：

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