Gets the maximum field value in the table and saves it in the foreground page

Get Useridfunction getUserId () {     $.getjson (' <%=basepath%>user/getuserid.do ',        function (data) {            Alert (eval (data). userId);            document.getElementById ("UserId"). Value=data.userid;    });       


<input id= "userid" name= "userid" value= "" type= "text" readonly= "readonly"/><input value= "Get maximum UserId" onclic K= "Javascript:getuserid ();" type= "button" style= "width:100px"/>            

Userslavecontroller Getting parameters

@ResponseBody//@ResponseBody Returns the data, without @ResponseBody the page is returned. @RequestMapping (value= "/user/getuserid.do")//method=requestmethod.postpublic jsonobject getUserId (    HttpServletRequest request, HttpServletResponse response) throws Exception {Response.setcontenttype ("text/html");    Request.setcharacterencoding ("Utf-8");    Response.setcharacterencoding ("Utf-8");        Jsonobject jsonobject = new Jsonobject ();        Integer userId = 0;                   try {userId = Userslaveservice.getuserid ();        } catch (Exception e) {loger.logtxt ("user", "Get ID Exception:" + e.tostring ());        } jsonobject.accumulate ("userid", UserID);     System.out.println (Jsonobject.tostring ());       Output: {"UserId": 182888} System.out.println (Jsonobject.values ());                             Output: [182888] return jsonobject; Returns the JSON, receives it in the JSP page above, and saves the value into input. }

Userslaveservice.java Interface declaration method: public Integer GetUserId () throws Exception;

Userslaveserviceimpl.java implements the Userslaveservice interface:

@Override
Public Integer GetUserId () throws Exception {
return Userdao.getuserid ();
}

Iuserdao.java Interface declaration method: public Integer GetUserId () throws Exception;

Queries in User.xml:

<select id= "GetUserId" resulttype= "Java.lang.Integer" >

<! [cdata[
SELECT (MAX (userid) +1) as UserID from UserInfo
]]>

　　

Gets the maximum field value in the table and saves it in the foreground page