$.ajax({
url : "user!findUserList.action",
type : "post",
success: function(data){
var jsonObj=eval("("+data+")");
$.each(jsonObj, function (i, item) {
jQuery("#userList").append("option value="+ item.userId+">"+ item.userRealName+"/option>");
});
},
error: function(text) {}
});

public void findUserList() throws IOException {
ListUserModel> roleuserList = userService.findUserList();
String json = JSONArray.fromObject(roleuserList).toString();
writeHtml(json);;
}

protected void writeHtml(String strData) {
try {
response.setContentType("text/html; charset=UTF-8");
PrintWriter pw = response.getWriter();
pw.write(strData);
pw.flush();
pw.close();
} catch (IOException e) {
log.error("writeHtml()", e);
}
}