pgx/examples/url_shortener/main.go

91 lines
2.2 KiB
Go

package main
import (
"context"
"io"
"log"
"net/http"
"os"
"github.com/jackc/pgx/v5"
"github.com/jackc/pgx/v5/pgxpool"
)
var db *pgxpool.Pool
func getUrlHandler(w http.ResponseWriter, req *http.Request) {
var url string
err := db.QueryRow(context.Background(), "select url from shortened_urls where id=$1", req.URL.Path).Scan(&url)
switch err {
case nil:
http.Redirect(w, req, url, http.StatusSeeOther)
case pgx.ErrNoRows:
http.NotFound(w, req)
default:
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
}
func putUrlHandler(w http.ResponseWriter, req *http.Request) {
id := req.URL.Path
var url string
if body, err := io.ReadAll(req.Body); err == nil {
url = string(body)
} else {
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
if _, err := db.Exec(context.Background(), `insert into shortened_urls(id, url) values ($1, $2)
on conflict (id) do update set url=excluded.url`, id, url); err == nil {
w.WriteHeader(http.StatusOK)
} else {
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
}
func deleteUrlHandler(w http.ResponseWriter, req *http.Request) {
if _, err := db.Exec(context.Background(), "delete from shortened_urls where id=$1", req.URL.Path); err == nil {
w.WriteHeader(http.StatusOK)
} else {
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
}
func urlHandler(w http.ResponseWriter, req *http.Request) {
switch req.Method {
case "GET":
getUrlHandler(w, req)
case "PUT":
putUrlHandler(w, req)
case "DELETE":
deleteUrlHandler(w, req)
default:
w.Header().Add("Allow", "GET, PUT, DELETE")
w.WriteHeader(http.StatusMethodNotAllowed)
}
}
func main() {
poolConfig, err := pgxpool.ParseConfig(os.Getenv("DATABASE_URL"))
if err != nil {
log.Fatalln("Unable to parse DATABASE_URL:", err)
}
db, err = pgxpool.NewWithConfig(context.Background(), poolConfig)
if err != nil {
log.Fatalln("Unable to create connection pool:", err)
}
http.HandleFunc("/", urlHandler)
log.Println("Starting URL shortener on localhost:8080")
err = http.ListenAndServe("localhost:8080", nil)
if err != nil {
log.Fatalln("Unable to start web server:", err)
}
}