Understanding Go's net/http package

Go's net/http package deals with HTTP client and server implementations. Here, we are mainly interested in the server implementation. Let us create a small Go program called basicHandler.go that defines the route and a function handler:

package main
import (
    "io"
    "net/http"
    "log"
)
// hello world, the web server
func MyServer(w http.ResponseWriter, req *http.Request) {
    io.WriteString(w, "hello, world!\n")
}
func main() {
    http.HandleFunc("/hello", MyServer)
    log.Fatal(http.ListenAndServe(":8000", nil))
}

This code does the following things: 

1. Create a route called  /hello. 
2. Create a handler called MyServer.
3. Whenever the request comes on the route (/hello), the handler function will be executed.
4. Write hello, world to the response.
5. Start the server on port 8000. ListenAndServe returns error if something goes wrong. So log it using log.Fatal.
6. The http package has a function called HandleFunc, using which we can map an URL to a function.

1. Here, w is a response writer. A ResponseWriter interface is used by an HTTP handler to construct an HTTP response.
2. req is a request object, which deals with all the properties and methods of an HTTP request.

Use the log function to debug potential errors. The ListenAndServe function returns an error if there are any.