流式响应

  • 当数据产生的时候发送数据
  • 使用分块传输编码（Chunked transfer encoding）的流式 JOSN 响应。

Server

server.go

  1. package main
  3. import (
  4.     "net/http"
  5.     "time"
  7.     "encoding/json"
  9.     "github.com/labstack/echo"
  10. )
  12. type (
  13.     Geolocation struct {
  14.         Altitude  float64
  15.         Latitude  float64
  16.         Longitude float64
  17.     }
  18. )
  20. var (
  21.     locations = []Geolocation{
  22.         {-97, 37.819929, -122.478255},
  23.         {1899, 39.096849, -120.032351},
  24.         {2619, 37.865101, -119.538329},
  25.         {42, 33.812092, -117.918974},
  26.         {15, 37.77493, -122.419416},
  27.     }
  28. )
  30. func main() {
  31.     e := echo.New()
  32.     e.GET("/", func(c echo.Context) error {
  33.         c.Response().Header().Set(echo.HeaderContentType, echo.MIMEApplicationJSON)
  34.         c.Response().WriteHeader(http.StatusOK)
  35.         for _, l := range locations {
  36.             if err := json.NewEncoder(c.Response()).Encode(l); err != nil {
  37.                 return err
  38.             }
  39.             c.Response().Flush()
  40.             time.Sleep(1 * time.Second)
  41.         }
  42.         return nil
  43.     })
  44.     e.Logger.Fatal(e.Start(":1323"))
  45. }

客户端

  1. $ curl localhost:1323

输出

  1. {"Altitude":-97,"Latitude":37.819929,"Longitude":-122.478255}
  2. {"Altitude":1899,"Latitude":39.096849,"Longitude":-120.032351}
  3. {"Altitude":2619,"Latitude":37.865101,"Longitude":-119.538329}
  4. {"Altitude":42,"Latitude":33.812092,"Longitude":-117.918974}
  5. {"Altitude":15,"Latitude":37.77493,"Longitude":-122.419416}