go-cache利用アプリ。

http-with-cache.go

package main

import (
	"database/sql"
	_ "github.com/go-sql-driver/mysql"
	"github.com/patrickmn/go-cache"
	"html/template"
	"net/http"
	"strconv"
	"time"
)

var c = cache.New(10*time.Minute, 30*time.Second)

func getValue() string {
	var targetId = 100000
	var key = strconv.Itoa(targetId)
	var pad string

  if x, found := c.Get(key); found {
      pad = x.(string)
  } else {
		db, err := sql.Open("mysql", "root@/sbtest")
		if err != nil {
			panic(err.Error())
		}
		defer db.Close()

		rows, err := db.Query("SELECT pad FROM sbtest WHERE id = " + key)
		defer rows.Close()
		if err != nil {
			panic(err.Error())
		}

		for rows.Next() {
			if err := rows.Scan(&pad); err != nil {
				panic(err.Error())
			}
		}
		c.Set(key, pad, cache.DefaultExpiration)
	}

	return pad
}

func viewHandler(w http.ResponseWriter, r *http.Request) {
	tmpl, err := template.ParseFiles("index.html")
	if err != nil {
		panic(err)
	}

	pad := getValue()
	err = tmpl.Execute(w, struct {
		Pad string
	}{
		Pad: pad,
	})

	if err != nil {
		panic(err)
	}
}

func main() {
	http.HandleFunc("/", viewHandler)
	http.ListenAndServe(":8081", nil)
}