Can you tell me whether I do an ajax asynchronous verify account why repeat what all don't show? Didn't found the problem, has set up a night
The script code:

 $(function () {
$(" # uname "). The onblur (function () {//when XXX loses focus 
Var value=https://bbs.csdn.net/topics/$(" # uname "). Val ();//to get id for XXX element 
$. Ajax ({
Url:/servlet/AjaxServlet,//to request the server url 
Data: {value} "val" :,//it is an object, which represents the request parameter server can use request, getParamet () to obtain 
If async: true,//for asynchronous request 
Cache: false,//cache the results 
Type: "POST",//request 
DataType: "json",//what type the json data is returned from the server: receiving an object 
Success: the function (result) {//this function can be carried on the server when success is called, parameters, the result is, the value of the server returns 
If (result) {
Document. The getElementById (" notice "). The innerText="existing"; 
} else {
Document. The getElementById (" notice "). The innerText="hh"; 
} 
} 
}); 
}); 
}); 

The JSP code:

 & lt; The form action="ZuCe_result. JSP method=" post "" name=" frm_register & gt;" 
 
 User name: & lt;/td> 
   
 

The servlet code:

 @ WebServlet ("/AjaxServlet ") 
Public class AjaxServlet extends the HttpServlet {
Private static final long serialVersionUID=1 l; 

/* * 
* @ see HttpServlet# HttpServlet () 
*/
Public AjaxServlet () {
Super (); 
//TODO Auto - generated constructor stub 
} 

/* * 
* @ see HttpServlet# doGet (it request, HttpServletResponse response) 
*/
Protected void doGet (it request, HttpServletResponse response) throws ServletException, IOException {
//TODO Auto - generated method stub 
request.setCharacterEncoding("utf-8"); 
The response. SetCharacterEncoding (" utf-8 "); 
The String value=https://bbs.csdn.net/topics/request.getParameter (" val ");//in adjx data set 
UserDao dao=new UserDao (); 
Boolean rs=dao. IsExitUname (" value "); 
If (rs) {
//use the jquery ajax callback function return value is the print the string 
The response. GetWriter (). Print (" true "); 
} else {
The response. GetWriter (). Print (" false "); 
} 

} 

/* * 
* @ see HttpServlet# doPost (it request, HttpServletResponse response) 
*/
Protected void doPost (it request, HttpServletResponse response) throws ServletException, IOException {
//TODO Auto - generated method stub 
DoGet (request, response); 
} 

} 

CodePudding user response:

Is anyone here??

CodePudding user response:

You need to have a problem, the url request path is/servlet/AjaxServlet in ajax, you have to @ WebServlet ("/AjaxServlet "), less a servlet, then test you can break point, if the request is coming after the background you can see

CodePudding user response:

refer to the second floor dhacker1 response:

you need to have a problem, the url request path is/servlet/AjaxServlet in ajax, you have to @ WebServlet ("/AjaxServlet "), less a servlet, then test you can break point, if the request is coming after the background you can see

thank you!! , the problem in this, I was looking for ages