jQuery Ajax请求后台数据并在前台接收

$.ajax({url: "r_getRolePer.action",dataType:'json', data: {userId:"1"}, //请求的附加参数，用json对象method:'POST',success: function(data){$.messager.alert('消息',data.add,'');//这里使用的时easyui的格式},});

public PrintWriter out()throws IOException{HttpServletResponse response=ServletActionContext.getResponse();     response.setContentType("text/html");     response.setContentType("text/plain; charset=utf-8");    PrintWriter out= response.getWriter();    return out;}*******JSONObject permision = new JSONObject();permision.put("add", 0);permision.put("delete", 0);permision.put("update", 0);out().print(permision.toString());out().flush();out().close();