good good study, day day up!

vendor/gopl.io/ch7/http2/main.go

@@ -0,0 +1,48 @@
+// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+// See page 192.
+
+// Http2 is an e-commerce server with /list and /price endpoints.
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+func main() {
+	db := database{"shoes": 50, "socks": 5}
+	log.Fatal(http.ListenAndServe("localhost:8000", db))
+}
+
+type dollars float32
+
+func (d dollars) String() string { return fmt.Sprintf("$%.2f", d) }
+
+type database map[string]dollars
+
+//!+handler
+func (db database) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	switch req.URL.Path {
+	case "/list":
+		for item, price := range db {
+			fmt.Fprintf(w, "%s: %s\n", item, price)
+		}
+	case "/price":
+		item := req.URL.Query().Get("item")
+		price, ok := db[item]
+		if !ok {
+			w.WriteHeader(http.StatusNotFound) // 404
+			fmt.Fprintf(w, "no such item: %q\n", item)
+			return
+		}
+		fmt.Fprintf(w, "%s\n", price)
+	default:
+		w.WriteHeader(http.StatusNotFound) // 404
+		fmt.Fprintf(w, "no such page: %s\n", req.URL)
+	}
+}
+
+//!-handler