Go-压缩响应中间件

package main

import (
	"compress/gzip"
	"io"
	"log"
	"net/http"
	"strings"
)

func main() {
	// 创建一个新的处理程序
	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// 向客户端发送一些数据
		w.Write([]byte("Hello, World!"))
	})

	// 使用压缩中间件装饰处理程序
	handler = compressionMiddleware(handler)

	// 注册处理程序并开始监听 HTTP 请求
	http.Handle("/", handler)
	log.Fatal(http.ListenAndServe(":8080", nil))
}

// 压缩中间件
func compressionMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// 检查客户端是否支持压缩
		encoding := r.Header.Get("Accept-Encoding")
		if strings.Contains(encoding, "gzip") {
			// 使用 Gzip 压缩算法压缩响应体
			w.Header().Set("Content-Encoding", "gzip")
			gz := gzip.NewWriter(w)
			defer gz.Close()
			next = &gzipResponseWriter{Writer: gz, ResponseWriter: w}
		} else if strings.Contains(encoding, "deflate") {
			// 使用 Deflate 压缩算法压缩响应体
			w.Header().Set("Content-Encoding", "deflate")
			df, _ := gzip.NewWriterLevel(w, gzip.DefaultCompression)
			defer df.Close()
			next = &gzipResponseWriter{Writer: df, ResponseWriter: w}
		}

		// 执行下一个处理程序
		next.ServeHTTP(w, r)
	})
}

// 带 Gzip 压缩的响应写入器
type gzipResponseWriter struct {
	io.Writer
	http.ResponseWriter
}

func (w *gzipResponseWriter) Write(data []byte) (int, error) {
	return w.Writer.Write(data)
}