Jquery ajax json 验证用户名是否存在

服务器(Terasoluna框架)以json的方式响应客户端      

1）客户端jquery相关代码：      

$("#idUser").blur(function(){
                $.post("a_usr_s03_ValidateUserIdAjaxBL.do",
                        {"idUser":$("#idUser").val(),  //需要验证的值

                        "validate_exit_msg":$("#validate_exit_msg").val()}, //当存在时返回的data（key：value）
                        function(date){          //回调函数
                            if(date!=null&&date!=""){
                                $("#idUserRequiredMsgtd").hide();
                                $("#ajaxValidateExittd").show().html(date);
                                $("#idUser").css({"border":"1px solid red"});
                                $(".btnSave").attr("disabled",true);
                            }else{
                                $("#idUser").css({"border":"1px solid #DBDFE6"});
                                $(".btnSave").removeAttr("disabled");
                            }
                });
            });
            $("#idUser").focus(function(){
                $("#idUserRequiredMsgtd").show();
                $("#ajaxValidateExittd").hide();
            });

jsp中的相关信息：

<input type="hidden" value="<bean:message key="errors.a_usr_s03.error1" />" id="validate_exit_msg" />  隐藏消息，当idUser存在时显示此消息

 

<td align="left" width="25%"><input type="text" id="idUser" class="disabled" name="idUser" maxlength="12" style=" 90%;background-color: white" value="<bean:write name="a_usr_s02Form" property="idUser" />" />
</td>
 <td align="left" width="20%" nowrap="nowrap" id="idUserRequiredMsgtd">&nbsp;</td>
<td id="ajaxValidateExittd" width="20%" nowrap="nowrap"></td>

       2）服务器端相关代码：

public class A_USR_S03_ValidateUserIdAjaxAction extends ActionEx {
    
    private QueryDAO queryDAO;

    /* (non-Javadoc)
     * @see jp.terasoluna.fw.web.struts.actions.ActionEx#doExecute(org.apache.struts.action.ActionMapping, org.apache.struts.action.ActionForm, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    @Override
    public ActionForward doExecute(ActionMapping mapping, ActionForm form, HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        PrintWriter out = response.getWriter();
        List<A_USR_S03_User> listUser = new ArrayList<A_USR_S03_User>();
        if(request.getParameter("idUser").trim()!=null&&request.getParameter("idUser").trim()!=""){
            String idUser=StringUtil.trim(request.getParameter("idUser")).toUpperCase();
            listUser = queryDAO.executeForObjectList("SELECT.A_USR_S03.CHECK_IDUSER", idUser);
        }
        if(listUser.size()==1){
            String message="<img src='../image/error.png'/><font color='red'>";
            message+=StringUtil.trim(request.getParameter("validate_exit"));
            message+="</font>";
            out.print(message);
            System.out.println(message);
            out.close();
        }
        return null;
    }

    public QueryDAO getQueryDAO() {
        return queryDAO;
    }

    public void setQueryDAO(QueryDAO queryDAO) {
        this.queryDAO = queryDAO;
    }
}