adaptor.md

title	Adaptor
date	2023-01-11
weight	16
keywords	Adaptor http.Request http.ResponseWriter net/http
description	Hertz provides access and related methods to Go standard library `http.Request` and `http.ResponseWriter`.

Hertz provides access and related methods to Go standard library http.Request and http.ResponseWriter, it is easy for users to integrate net/http to develop application.

Note: This adaptation comes at a performance penalty

Example

package main

import (
	"context"
	"fmt"
	"net/http"

	"github.com/cloudwego/hertz/pkg/app"
	"github.com/cloudwego/hertz/pkg/app/server"
	"github.com/cloudwego/hertz/pkg/common/adaptor"
)

func handler(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(200)

	_, err := w.Write([]byte("Hello World"))
	if err != nil {
		fmt.Println(err)
		return
	}
}

func main() {
	h := server.Default()

	h.GET("/hello", func(ctx context.Context, c *app.RequestContext) {
		req, err := adaptor.GetCompatRequest(&c.Request)
		if err != nil {
			fmt.Println(err)
			return
		}
		// You may build more logic on req
		fmt.Println(req.URL.String())

		// caution: don't pass in c.GetResponse() as it return a copy of response
		rw := adaptor.GetCompatResponseWriter(&c.Response)

		handler(rw, req)
	})

	h.Spin()
}

http.Request

Function	Function Signature	Description
GetCompatRequest	func GetCompatRequest(req *protocol.Request) (*http.Request, error)	Deprecated: Please use adaptor.HertzHandler instead. Build and fetch Go standard library http.Request from Hertz protocol.Request
CopyToHertzRequest	func CopyToHertzRequest(req *http.Request, hreq *protocol.Request)	Copy the URI, Host, Method, Protocol, Header of Go standard library http.Request to Hertz protocol.Request, The Body field will be adapted by sharing Reader

http.ResponseWriter

Function / Struct	Function Signature	Description
GetCompatResponseWriter	func GetCompatResponseWriter(resp *protocol.Response) http.ResponseWriter	Deprecated: Please use adaptor.HertzHandler instead. Build and fetch Go standard library http.ResponseWriter from Hertz protocol.Response
compatResponse	/	compatResponse implements the http.ResponseWriter interface and has adaptations to Header, Write and WriteHeader functions

Handler

Hertz pprof middleware provides adaptation methods for the Go standard library http.Handler and http.HandlerFunc, it is easy for users to adapt to Hertz app.HandlerFunc for development.

Function	Function Signature	Description
NewHertzHTTPHandlerFunc	func NewHertzHTTPHandlerFunc(h http.HandlerFunc) app.HandlerFunc	Used to convert Go standard library http.HandlerFunc to Hertz app.HandlerFunc
NewHertzHTTPHandler	func NewHertzHTTPHandler(h http.Handler) app.HandlerFunc	Used to convert Go standard library http.Handler to Hertz app.HandlerFunc

Note

• When modifying the resp header in the server handler, please use write function to write the header. Otherwise, the modification will not take effect.

func handler(resp http.ResponseWriter, req *http.Request) {
    resp.Header().Add("Content-Encoding", "test")
    _, err := resp.Write([]byte("Content-Encoding: test\n"))
    if err != nil {
        panic(err)
    }
}

Refer to hertz-example and pprof for more information