在spring MVC hibernate注释中将下拉列表中选定项的值传递给控制器

Question

嗨，在我的spring hibernate注释应用程序中，我使用jsp作为视图。在jsp我加载值从我的mysql数据库下拉列表。但是我不能将所选值从jsp页面传输到控制器。我有两个表雇员表和团队表在mysql。我想显示所选团队中的所有员工。例如，如果我选择team1从下拉菜单，我想在team1中显示所有员工。在点击提交按钮时，我得到了空点异常错误。

加载mysql数据库值到下拉列表的JSP页面代码片段

 <form:form method="POST" action="Search.html">
  <table>
    <tr>
        <td>
                        <form:label path="teams.teamId" id="teams">Team Name</form:label>
                    </td>
                    <td>
                        <form:select path="teams.teamId" cssStyle="width: 150px;">    
                            <option value="-1">Select a type</option>
                            <c:forEach items="${teamKey}" var="teams">
                            <option value="${teams.teamId}" >${teams.teamName}</option>
                            </c:forEach>
                             <tr>
                       <td colspan="2"><input type="submit"  value="submit">  </td>
</tr>
                        </form:select>
    </tr>
   </table>
</form:form>

Hibernate select query in resourcedaoimpl

 @Override
public void serchResources(int teamid) {
    // TODO Auto-generated method stub
    System.out.println("teamid is given----------  :"+teamid);
    sessionfactory.getCurrentSession().createQuery("FROM Resource WHERE teamId=" +teamid);

    System.out.println("After query  teamid is given--*************  :"+teamid);
}

contrtoller类

@RequestMapping(value="/Search",method = RequestMethod.POST)
    public ModelAndView fromSearch(@ModelAttribute("command") Resource resource,BindingResult result){
        return new ModelAndView("redirect:/searchResult.html");
    }

@RequestMapping(value="/searchResult",method = RequestMethod.GET)
public ModelAndView searchResult(@ModelAttribute("command") Resource resource,BindingResult result){
    Map<String, Object> model = new HashMap<String, Object>();
    //to  print employee table
    model.put("resourcekey",resourceServices.listResources());
    //lists teams
    model.put("teamKey", addteamServices.listTeams());
    return new  ModelAndView("Search",model);
}

谢谢你的建议

Answer 1

您需要在表单标签中包含modelAttribute，

<form:form method="POST" action="Search.html" modelAttribute="command" >

当你试图在控制器