错误写法
func main() {
openHttpListen()
}
func openHttpListen() {
http.HandleFunc("/", receiveClientRequest)
fmt.Println("go server start running...")
err := http.ListenAndServe(":9090", nil)
if err != nil {
log.Fatal("ListenAndServe: ", err)
}
}
func receiveClientRequest(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Access-Control-Allow-Origin", "*") //允许访问所有域
w.Header().Add("Access-Control-Allow-Headers", "Content-Type") //header的类型
w.Header().Set("content-type", "application/json") //返回数据格式是json
r.ParseForm()
fmt.Println("收到客户端请求: ", r.Form)
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这样还是会报错：
说没有得到响应跨域的头，chrome的network中确实没有响应Access-Control-Allow-Origin
正确写法：
func LDNS(w http.ResponseWriter, req *http.Request) {
if origin := req.Header.Get("Origin"); origin != "" {
w.Header().Set("Access-Control-Allow-Origin", origin)
w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
w.Header().Set("Access-Control-Allow-Headers",
"Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
}
if req.Method == "OPTIONS" {
return
}
// 响应http code
w.WriteHeader(200)
query := strings.Split(req.Host, ".")
value, err := ldns.RAMDBMgr.Get(query[0])
fmt.Println("Access-Control-Allow-Origin", "*")
if err != nil {
io.WriteString(w, `{"message": ""}`)
return
}
io.WriteString(w, value)
}
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补充：go http允许跨域
1.创建中间件
import (
"github.com/gin-gonic/gin"
"net/http"
)
// 跨域中间件
func Cors() gin.HandlerFunc {
return func(c *gin.Context) {
method := c.Request.Method
origin := c.Request.Header.Get("Origin")
if origin != "" {
c.Header("Access-Control-Allow-Origin", origin)
c.Header("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE, UPDATE")
c.Header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization")
c.Header("Access-Control-Expose-Headers", "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers, Cache-Control, Content-Language, Content-Type")
c.Header("Access-Control-Allow-Credentials", "false")
c.Set("content-type", "application/json")
}
if method == "OPTIONS" {
c.AbortWithStatus(http.StatusNoContent)
}
c.Next()
}
}
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2.在route中引用中间件
router := gin.Default()
// 要在路由组之前全局使用「跨域中间件」, 否则OPTIONS会返回404
router.Use(Cors())
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