JavaScript Ajax Json realizes linkage between upper and lower drop-down boxes

最近尝试做出一个部门和人员的下拉框联动功能，部门和人员的对应关系是1:N

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The onchange() event of the department drop-down box takes an AJAX method and returns a JSON object (the JSON contains a LIST).

js method is written on this page:

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The data returned here contains list (see list below), and the list contains two attributes: the person's code and the person's name. Then empty() the personnel drop-down box first, and add a new drop-down box element through the select control append method.

Backend code:

[java]

public String departmentChangeEvent() throws Exception{

                                                                  use using List.size()> ;0)

                                                                                                                                                                                           HttpServletResponse response = ServletActionContext.getResponse();            response.setHeader("Pragma","No-cache ");

Response.Setheader (" Cache-Control "," No-Cache ");

Response.Setheader (" Cache-Control "," No-Store "); twriter ( ; JSONObject jso = JSONObject.fromObject(map);

writer .write(jso.toString());

          writer.flush();                 writer.close();

                                                                                                                                                    using  departmentCode (field field with set, get) to retrieve the users under the current department and put them into the userList. www.2cto.com

Then put the userList into a defined HashMap through standard writing, and the KEY is list.

[java]

JSONObject jso = JSONObject.fromObject(map);

This is the most critical step. Some json object creation methods can also be JSONObject jso = new JSONObject( ); Then put the records in the list into jso. . .

It won’t work here, the frontend will think that the returned value is a string. . . The return type in

struts is json

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                                                                                                                   ;/result>