spring 组合查询 报错? 400 报错

我的查询如下：

<!--申报列表查询框 -->
<div id="contentarea">      
    <div id="lb"><div id="rb"><div id="bb"><div id="blc">
    <div id="brc"><div id="tb"><div id="tlc"><div id="trc">
    <div id="content">
<form:form  action="${pageContext.request.contextPath}/selectApplicationList" method="POST" modelAttribute="project">
 <table cellpadding="0"  cellspacing="0" id="viewTable" >
 <tbody>
 <tr>
     <td class="label" valign="top">
        <fmt:message key="project.projectname.title"/>:
    </td><td>
        <form:input id="project_projectName" path="projectName" cssStyle="width:300px;"/>
    </td><td class="label" valign="top">
     <fmt:message key="projectartical.responserid.title"/>:
    </td><td>                            
     <!--负责人下拉框选择-->                
      <form:select path="user.id" id="projectartical.responserid" cssStyle=" width:300px;">
        <form:option value="" label="--Please Select"/>
        <form:options items="${users}"/>
       </form:select>    
     <!-- 负责人下拉框选择 -->                                
    </td>                
 </tr><tr>
     <td class="label" valign="top">
        <fmt:message key="projectapplication.applicationdate.title"/><fmt:message key="from"/>:
     </td><td>
        <input id="projectApplication_applicationDate" name="applicationDate"  dojoType="dijit.form.DateTextBox" constraints="{datePattern:'<fmt:message key="date.format"/>'}" trim="true" promptMessage="<fmt:message key="date.format" />" invalidMessage="<fmt:message key="date.format.invalid" /> <fmt:message key="date.format" />." style="width:300px;"/>
     </td><td class="label" valign="top">
    <fmt:message key="to"/>:
     </td><td>                            
     <input id="project_endDate" name="endDate"  dojoType="dijit.form.DateTextBox" constraints="{datePattern:'<fmt:message key="date.format"/>'}" trim="true" promptMessage="<fmt:message key="date.format" />" invalidMessage="<fmt:message key="date.format.invalid" /> <fmt:message key="date.format" />." style="width:300px;" />                                
     </td>                
 </tr>
 <tr>
 <td colspan="4">
 <span class="inputbutton"><input class="savebutton" id="save" type="submit" value="<fmt:message key="navigation.view"/>"/></span>
            <script type="text/javascript">Spring.addDecoration(new Spring.ValidateAllDecoration({elementId:'save', event:'onclick'}));</script>
 </td>
</tr>
 </tbody>
   </table>
 </form:form>
</div>
</div></div></div></div>
    </div></div></div></div>
</div>

control层是这么写的：

/**
     * Select all Project entities by Project
     *
     */
    @RequestMapping("/selectApplicationList")
    @ResponseBody
    public ModelAndView selectApplicationList( @RequestParam String projectName,@RequestParam Integer username,@ModelAttribute Project project) {
        ModelAndView mav = new ModelAndView();
        mav.addObject("projects",myProjectService.findProjects(projectName, username));
        mav.setViewName("_project/selectApplicationList.jsp");
        return mav;
    }

我点击查询时就报如下错：

HTTP Status 400 -

type Status report

message

description The request sent by the client was syntactically incorrect ().

Apache Tomcat/6.0.32