为什么我按上一页会直接跳到登录页面

<table border="0" cellspacing="0" cellpadding="0" align="center">

  <tr>

    <td align="right">

      <span>第<s:property value="currPage"/>/<s:property value="totalPage"/>页</span>&nbsp;&nbsp;

      <span>总记录数：<s:property value="totalCount"/>&nbsp;&nbsp;每页显示：<s:property value="pageSize"/></span>&nbsp;&nbsp;

      <span>

        <s:if test="currPage != 1">

          <a href="${pageContext.request.contextPath }/user_findAll.action?currPage=1">[首页]</a>&nbsp;&nbsp;

          <a href="${pageContext.request.contextPath }/user_findAll.action?currPage=<s:property value="currPage-1"/>">[上一页]</a>&nbsp;&nbsp;

        </s:if>

        <s:if test="currPage != totalPage">

          <a href="${pageContext.request.contextPath }/user_findAll.action?currPage=<s:property value="currPage+1"/>">[下一页]</a>&nbsp;&nbsp;

          <a href="${pageContext.request.contextPath }/user_findAll.action?currPage=<s:property value="totalPage"/>">[尾页]</a>&nbsp;&nbsp;

        </s:if>

      </span>

    </td>

  </tr>

</table>