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HTTP Client and Server

The HTTP protocol is used to communicate between Client and Server. The net/http package provides all methods needed to implement a client and a server and the most commonly used request methods.

The most commonly used request methods are:

  • GET:
    • This method is used to request data from the server or specified source. Used for fetching data.
  • POST:
    • This method is used to send a request with data in the body to a server. Used for creating data.
  • PATCH:
    • This method is used to partially update an existing data entry.
  • PUT:
    • This method is used to entirely update an existing data entry.

HTTP Client​

The HTTP Client consumes the API, it sends a request to the HTTP Server. The following code shows an example for all the commonly used HTTP requests.


// GET Requests: Pass the URL to request the data from.
// Returns a response and an error.
resp, err := http.Get("https://foomo.org") 

// Post Requests: Pass the URL to post data to, specify the content type of the data, 
// and pass the body containing the data of the request.
// Returns a response and an error.
resp, err := http.Post("https://foomo.org", "application/json", body)

// PATCH Requests, specify it's a PATCH request, pass the URL to request, 
// and the body containing the data of the request.
// Returns a response and an error.
resp, err := http.NewRequest(http.MethodPatch, "https://foomo.org", body) 

// PUT Requests, specify it's a PUT request, pass the URL to request,
// and the body containing the data of the request.
// Returns a response and an error.
resp, err := http.NewRequest(http.MethodPut, "https://foomo.org", body)

HTTP Server​

the HTTP Server accepts API calls from a Client. Handlers are a fundamental concept in the net/http package. They are your way of basically telling how a request is supposed to be handled. Handler functions always take a ResponseWriter and a pointer to a Request as argument:

func myHandler(w http.ResponseWriter, req *http.Request) {
    ...
}

In the main function of your server you register all the handlers implemented and serve them on a specified port:

func main () {

    http.HandleFunc("/myPage", myHandler) // specify the path and the handler function

    http.ListenAndServe(":8000", nil) // specify the port and the router, which is the default router in this case.
}

RESTful​