Return plain text body in HTTP response in Go (Golang)

Overview

Write method of the ResponseWriter interface in net/http package can be used to set the text/plain body in an HTTP response

In GO a response is represented by the ResponseWriter Interface.  Here is the link to the interface –https://golang.org/pkg/net/http/#ResponseWriter

ResponseWriter interface is used by an HTTP handler to construct an HTTP response. It provides three functions to set the response parameters

• Header – For writing response header

• Write([]byte) – For writing response body

• WriteHeader(statusCode int) – For writing the http status code

Write function can be used to set the response body. It takes a slice of bytes as input. Also, there is a Header function. This function can be used to set the content type of the response body using the Content-Type header. For eg in the case of the text/plain response body, we need to set the Content-Type header as “text/plain”.

w.Header().Set("Content-Type", "text/plain")

Also, note that WriteHeader function can be used to set the HTTP status code for the response

Example

Let’s see an example of sending http status code and text/plain response body

Below is the program for the same

package main

import (
	"net/http"
)

func main() {
	handler := http.HandlerFunc(handleRequest)
	http.Handle("/example", handler)
	http.ListenAndServe(":8080", nil)
}

func handleRequest(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Header().Set("Content-Type", "application/text")
	w.Write([]byte("Success"))
	return
}

We use the Write function to return the text/plain response body. The above code returns the below text/plain body back in response

Success

Also, we are using the WriteHeader function to specify the 200 http status code.  We are also setting the correct header

Run the above program. It will start a server on 8080 port on your local machine. Now make the below curl call to the server

curl -v -X POST http://localhost:8080/example

Below will be the output

* Connected to localhost (::1) port 8080 (#0)
> POST /example HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.54.0
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Sat, 10 Jul 2021 19:01:56 GMT
< Content-Length: 7
< Content-Type: text/plain; charset=utf-8
< 
* Connection #0 to host localhost left intact
Success

As you can see from the output, it will correctly return the 200 status code along with the text/plain body. Also, the Content-Type response header is set to text/plain

Also, check out our Golang advance tutorial Series - Golang Advance Tutorial