Database server in Go that uses url.Value as temporary key-value store and path parameter + query string to set and get data.

server.go

/* Database server */

package main

import (
        "fmt"
        "html"
        "log"
        "net/http"
        "net/url"
)

// Temporary data store                                                                                                         
var db = url.Values{}

// urlHandler parses the request URL for path and query string, then decide whether to set or get data.                         
func urlHandler(next http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
                method := html.EscapeString(r.URL.Path[1:])
                current := r.URL.Query()
                switch method {
                case "set":
                        for key, vals := range current {
                                log.Printf("Setting %q: %q", key, vals[0])
                                db.Set(key, vals[0])
                        }
                case "get":
                        for key, kvs := range current {
                                if key == "key" {
                                        first := db.Get(kvs[0])
                                        log.Printf("Getting %q: %q", kvs[0], first)
                                        r.Header.Add(kvs[0], first)
                                }
                        }
                }

                // Call the next middleware                                                                                     
                next.ServeHTTP(w, r)
        })
}

// writeData invoke on a "get" operation and print the data stored at a given key to the browser.                               
func writeData(w http.ResponseWriter, r *http.Request) {
        current := r.URL.Query()
        for k, kv := range(current) {
                if k == "key" {
                        fmt.Fprintf(w, r.Header.Get(kv[0]))
                }
        }
}

func main() {
        webWriter := http.HandlerFunc(writeData)
        http.Handle("/", urlHandler(webWriter))

        // Run server at port 4000                                                                                              
        log.Fatal(http.ListenAndServe(":4000", nil))
}