100 lines
2.6 KiB
Go
100 lines
2.6 KiB
Go
package main
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import (
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"image"
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"image/gif"
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"log"
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"net/http"
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"os"
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"regexp"
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"strconv"
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"github.com/chai2010/webp"
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"github.com/disintegration/imaging"
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)
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// 实现一个 web api 服务(获取指定尺寸的图片)
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func main() {
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http.HandleFunc("/img/", func(w http.ResponseWriter, r *http.Request) {
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// URL 格式: /img/{id}-{version}@{倍图}{宽度}.{格式}
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reg := regexp.MustCompile(`^/img/([0-9a-zA-Z]+)-([0-9a-zA-Z]+)@([0-9]{1,4})x([0-9]{1,4}).(jpg|jpeg|png|webp)$`)
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matches := reg.FindStringSubmatch(r.URL.Path)
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if len(matches) != 6 {
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log.Println("URL 格式错误", matches)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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// 正则表达式获取参数
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id, version, multiple_str, width_str, format := matches[1], matches[2], matches[3], matches[4], matches[5]
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multiple, err := strconv.Atoi(multiple_str)
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if err != nil {
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log.Println("倍图参数错误", multiple_str)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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width, err := strconv.Atoi(width_str)
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if err != nil {
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log.Println("宽度参数错误", width_str)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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log.Println(id, version, multiple, width, format)
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// 打開輸入文件
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file, err := os.Open("data/test.gif")
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if err != nil {
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log.Println("打开文件失败", err)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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defer file.Close()
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// 將輸入文件解碼為 image.Image
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img, ext, err := image.Decode(file)
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if err != nil {
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log.Println("解码图像失败", err)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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// 如果是 GIF 格式的动态图片，直接返回
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if ext == "gif" {
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giffile, err := os.Open("data/test.gif")
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if err != nil {
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log.Println("打开文件失败", err)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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defer giffile.Close()
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gifimg, err := gif.DecodeAll(giffile)
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if err != nil {
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log.Println("解码图像失败", err)
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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gif.EncodeAll(w, gifimg)
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return
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}
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// 將圖像轉換為 RGBA 格式（如果尚未採用該格式）
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if _, ok := img.(*image.RGBA); !ok {
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img = imaging.Clone(img)
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}
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// 將圖像調整為指定宽度的 WebP 格式並將其寫入輸出到瀏覽器(高度自适应)
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if err = webp.Encode(w, imaging.Resize(img, multiple*width, 0, imaging.Lanczos), &webp.Options{Quality: 80}); err != nil {
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log.Println("编码图像失败", err.Error())
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w.WriteHeader(http.StatusBadRequest)
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return
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}
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})
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log.Println("Server is running at http://localhost:6001")
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http.ListenAndServe(":6001", nil)
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}
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