init

bin/main.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"image"
+	"image/gif"
+	"log"
+	"net/http"
+	"os"
+
+	"regexp"
+	"strconv"
+
+	"github.com/chai2010/webp"
+	"github.com/disintegration/imaging"
+)
+
+// 实现一个 web api 服务(获取指定尺寸的图片)
+func main() {
+
+	http.HandleFunc("/img/", func(w http.ResponseWriter, r *http.Request) {
+
+		// URL 格式: /img/{id}-{version}@{倍图}{宽度}.{格式}
+		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)$`)
+		matches := reg.FindStringSubmatch(r.URL.Path)
+		if len(matches) != 6 {
+			log.Println("URL 格式错误", matches)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+
+		// 正则表达式获取参数
+		id, version, multiple_str, width_str, format := matches[1], matches[2], matches[3], matches[4], matches[5]
+		multiple, err := strconv.Atoi(multiple_str)
+		if err != nil {
+			log.Println("倍图参数错误", multiple_str)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+
+		width, err := strconv.Atoi(width_str)
+		if err != nil {
+			log.Println("宽度参数错误", width_str)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+
+		log.Println(id, version, multiple, width, format)
+
+		// 打開輸入文件
+		file, err := os.Open("data/test.gif")
+		if err != nil {
+			log.Println("打开文件失败", err)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		defer file.Close()
+
+		// 將輸入文件解碼為 image.Image
+		img, ext, err := image.Decode(file)
+		if err != nil {
+			log.Println("解码图像失败", err)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+
+		// 如果是 GIF 格式的动态图片，直接返回
+		if ext == "gif" {
+			giffile, err := os.Open("data/test.gif")
+			if err != nil {
+				log.Println("打开文件失败", err)
+				w.WriteHeader(http.StatusBadRequest)
+				return
+			}
+			defer giffile.Close()
+			gifimg, err := gif.DecodeAll(giffile)
+			if err != nil {
+				log.Println("解码图像失败", err)
+				w.WriteHeader(http.StatusBadRequest)
+				return
+			}
+			gif.EncodeAll(w, gifimg)
+			return
+		}
+
+		// 將圖像轉換為 RGBA 格式（如果尚未採用該格式）
+		if _, ok := img.(*image.RGBA); !ok {
+			img = imaging.Clone(img)
+		}
+
+		// 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)
+		if err = webp.Encode(w, imaging.Resize(img, multiple*width, 0, imaging.Lanczos), &webp.Options{Quality: 80}); err != nil {
+			log.Println("编码图像失败", err.Error())
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+	})
+	log.Println("Server is running at http://localhost:6001")
+	http.ListenAndServe(":6001", nil)
+}