Nesting Java code in JS

In the JSP sometimes in JS operation some Java background pass over the data logic more complex, such as the list content traversal, you can directly add Java script on the page to execute the content, the code is as follows:

        //inserting Java code actions in JS<%//Remove the Java background settings userlistList<map<string,string>> userlist = (list<map<string,string>>) request.getAttribute (" UserList "); //instantiate if the value of userlist is null              if(userlist==NULL) {userlist=NewArraylist<map<string,string>>(); }        %>//If there is data in the UserList          if(<%=userlist.size ()%>>0) {          <%//traversing the contents of a list                   for(map<string,string>user:userlist) {String UserId= User.get ("UserId"); String UserName= User.get ("UserName"); %>//invoke the JS method in the Java traversal, and pass the parameterToadd ("<%=userId%>", "<%=userName%>"); <%                  }          %>//if userlist in ignorance will be the Java background set up two parameters to take out the parameters}Else{            //Sales Person IDvar userId = "${userid}"; //name of sales personvar userName = "${username}";        Toadd (Userid,username); }

This operation eliminates the JS page to receive Java data content, Java code is as follows:

New Arraylist<map<string,string>>(); MapNew hashmap<string,string>(); Map.put ("UserId", "1"), Map.put ("UserName", "Water Wolf"); Maplist.add (map); Req.setattribute ("userlist", maplist);

Nesting Java code in JS