从数据库动态添加数据到下拉框（select）中

在controller中：

@RequestMapping("/type")
public String getType(HttpServletRequest req, HttpServletResponse rsp)
throws IOException {
req.setCharacterEncoding("utf-8");
rsp.setCharacterEncoding("utf-8");
System.out.println("进入gettype......");
List<Book> listType = libraryService.getBookType();
PrintWriter out=rsp.getWriter();
out.print(JSON.toJSONString(listType));
return null;
}

页面上：

<select id="sel_menu3" ></select>

js函数：

function cc(){
 $.post("<%=path%>/home/type",