golang实现图片缩放服务器

测试地址

中间数字是图片尺寸

package main

import (

    "fmt"

    "graphics"

    "image"

    "image/png"

    "log"

    "net/http"

    "os"

    "strconv"

    "strings"

)

func main() {

    http.HandleFunc("/", doImageHandler)

    http.ListenAndServe("127.0.0.1:6789", nil)

}

func doImageHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Printf("%q\n", strings.Split(r.URL.Path, "/"))
    url := strings.Split(r.URL.Path, "/")
    if len(url) != 3 {
        return
    }
    newdx, uerr := strconv.Atoi(url[1])
    if uerr != nil {
        log.Fatal(uerr)
    }
    src, err := LoadImage(url[2])
    bound := src.Bounds()
    dx := bound.Dx()
    dy := bound.Dy()
    if err != nil {
        log.Fatal(err)
    }
    // 缩略图的大小
    dst := image.NewRGBA(image.Rect(0, 0, newdx, newdx*dy/dx))
    // 产生缩略图,等比例缩放
    err = graphics.Scale(dst, src)
    if err != nil {
        log.Fatal(err)
    }
    header := w.Header()
    header.Add("Content-Type", "image/jpeg")
    
    png.Encode(w, dst)
}

// Load Image decodes an image from a file of image.

func LoadImage(path string) (img image.Image, err error) {

    file, err := os.Open(path)

    if err != nil {

        return

    }

    defer file.Close()

    img, _, err = image.Decode(file)

    return

}