48 lines
1.0 KiB
Go
48 lines
1.0 KiB
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 195.
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// Http4 is an e-commerce server that registers the /list and /price
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// endpoint by calling http.HandleFunc.
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package main
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import (
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"fmt"
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"log"
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"net/http"
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)
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//!+main
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func main() {
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db := database{"shoes": 50, "socks": 5}
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http.HandleFunc("/list", db.list)
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http.HandleFunc("/price", db.price)
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log.Fatal(http.ListenAndServe("localhost:8000", nil))
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}
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//!-main
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type dollars float32
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func (d dollars) String() string { return fmt.Sprintf("$%.2f", d) }
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type database map[string]dollars
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func (db database) list(w http.ResponseWriter, req *http.Request) {
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for item, price := range db {
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fmt.Fprintf(w, "%s: %s\n", item, price)
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}
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}
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func (db database) price(w http.ResponseWriter, req *http.Request) {
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item := req.URL.Query().Get("item")
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if price, ok := db[item]; ok {
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fmt.Fprintf(w, "%s\n", price)
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} else {
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w.WriteHeader(http.StatusNotFound) // 404
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fmt.Fprintf(w, "no such item: %q\n", item)
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}
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}
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