{"id":5930,"date":"2021-07-10T22:26:58","date_gmt":"2021-07-10T16:56:58","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=5930"},"modified":"2021-07-11T00:45:37","modified_gmt":"2021-07-10T19:15:37","slug":"json-response-body-http-go","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/","title":{"rendered":"Return JSON body in HTTP response in Go (Golang)"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_17 counter-hierarchy counter-decimal ez-toc-light-blue\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" style=\"display: none;\"><i class=\"ez-toc-glyphicon ez-toc-icon-toggle\"><\/i><\/a><\/span><\/div>\n<nav><ul class=\"ez-toc-list ez-toc-list-level-1\"><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/#Overview\" title=\"Overview\">Overview<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/#Example\" title=\"Example\">Example<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"has-luminous-vivid-orange-color has-text-color wp-block-heading\"><span class=\"ez-toc-section\" id=\"Overview\"><\/span><strong>Overvie<\/strong>w<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Write<\/strong> method of the ResponseWriter interface in <strong>net\/http<\/strong> package can be used to set the JSON body in an HTTP response<\/p>\n\n\n\n<p class=\"has-medium-font-size\">In GO a response is represented by the&nbsp;<strong>ResponseWriter<\/strong>&nbsp;Interface.&nbsp; Here is the link to the interface \u2013<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><a href=\"https:\/\/golang.org\/pkg\/net\/http\/#ResponseWriter\">https:\/\/golang.org\/pkg\/net\/http\/#ResponseWriter<\/a><\/p>\n\n\n\n<p class=\"has-medium-font-size\">ResponseWriter interface is used by an HTTP handler to construct an HTTP response. It provides three functions to set the response parameters<\/p>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>Header \u2013 For writing response header<\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>Write([]byte) \u2013 For writing response body<\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>WriteHeader(statusCode int) \u2013 For writing the http status code<\/li><\/ul>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Write<\/strong> function can be used to set the response body. It takes a slice of bytes as input. Also, there is a <strong>Header <\/strong>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 JSON response body, we need to set the Content-Type header as <strong>&#8220;application\/json&#8221;.<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">w.Header().Set(\"Content-Type\", \"application\/json\")<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Also, note that <strong>WriteHeader <\/strong>function can be used to set the HTTP status code for the response<\/p>\n\n\n\n<h2 class=\"has-luminous-vivid-orange-color has-text-color wp-block-heading\"><span class=\"ez-toc-section\" id=\"Example\"><\/span><strong>Example<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"has-medium-font-size\">Let&#8217;s see an example of sending http status code and JSON response body<\/p>\n\n\n\n<p class=\"has-medium-font-size\">Below is the program for the same<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">package main\n\nimport (\n\t\"encoding\/json\"\n\t\"log\"\n\t\"net\/http\"\n)\n\nfunc main() {\n\thandler := http.HandlerFunc(handleRequest)\n\thttp.Handle(\"\/example\", handler)\n\thttp.ListenAndServe(\":8080\", nil)\n}\n\nfunc handleRequest(w http.ResponseWriter, r *http.Request) {\n\tw.WriteHeader(http.StatusCreated)\n\tw.Header().Set(\"Content-Type\", \"application\/json\")\n\tresp := make(map[string]string)\n\tresp[\"message\"] = \"Status Created\"\n\tjsonResp, err := json.Marshal(resp)\n\tif err != nil {\n\t\tlog.Fatalf(\"Error happened in JSON marshal. Err: %s\", err)\n\t}\n\tw.Write(jsonResp)\n\treturn\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">In the above program, this is how we create a JSON response. We use the <strong>json.Marshal<\/strong> function to convert the <strong>map[string]string<\/strong> into json bytes.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">resp := make(map[string]string)\nresp[\"message\"] = \"Status Created\"\njsonResp, err := json.Marshal(resp)\nif err != nil {\n\tlog.Fatalf(\"Error happened in JSON marshal. Err: %s\", err)\n}\nw.Write(jsonResp)<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">It then uses the <strong>Write<\/strong> function to return the JSON response body. The above code returns the below JSON response body back in response<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">{\"message\":\"Status Created\"}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Also, we are using the <strong>WriteHeader<\/strong> function to specify the 201 http status code.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">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<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">curl -v -X POST http:\/\/localhost:8080\/example<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Below will be the output<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">* Connected to localhost (::1) port 8080 (#0)\n> POST \/example HTTP\/1.1\n> Host: localhost:8080\n> User-Agent: curl\/7.54.0\n> Accept: *\/*\n> \n< HTTP\/1.1 201 Created\n< Date: Sat, 10 Jul 2021 10:40:33 GMT\n< Content-Length: 28\n< Content-Type: text\/plain; charset=utf-8\n< \n* Connection #0 to host localhost left intact\n{\"message\":\"Status Created\"}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">As you can see from the output, it will correctly return the <strong>201<\/strong> status code along with the JSON body.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">Also, check out our Golang advance tutorial Series - <a href=\"https:\/\/golangbyexamples.com\/golang-comprehensive-tutorial\/\">Golang Advance Tutorial<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Table of Contents OverviewExample Overview Write method of the ResponseWriter interface in net\/http package can be used to set the JSON body in an HTTP response In GO a response is represented&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[1],"tags":[3,4],"class_list":["post-5930","post","type-post","status-publish","format-standard","hentry","category-tech","tag-go","tag-golang"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Return JSON body in HTTP response in Go (Golang) - Welcome To Golang By Example<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Return JSON body in HTTP response in Go (Golang) - Welcome To Golang By Example\" \/>\n<meta property=\"og:description\" content=\"Table of Contents OverviewExample Overview Write method of the ResponseWriter interface in net\/http package can be used to set the JSON body in an HTTP response In GO a response is represented...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/\" \/>\n<meta property=\"og:site_name\" content=\"Welcome To Golang By Example\" \/>\n<meta property=\"article:published_time\" content=\"2021-07-10T16:56:58+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2021-07-10T19:15:37+00:00\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/\",\"url\":\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/\",\"name\":\"Return JSON body in HTTP response in Go (Golang) - Welcome To Golang By Example\",\"isPartOf\":{\"@id\":\"https:\/\/golangbyexamples.com\/#website\"},\"datePublished\":\"2021-07-10T16:56:58+00:00\",\"dateModified\":\"2021-07-10T19:15:37+00:00\",\"author\":{\"@id\":\"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f\"},\"breadcrumb\":{\"@id\":\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/golangbyexamples.com\/json-response-body-http-go\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/golangbyexamples.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Return JSON body in HTTP response in Go (Golang)\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/golangbyexamples.com\/#website\",\"url\":\"https:\/\/golangbyexamples.com\/\",\"name\":\"Welcome To Golang By Example\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/golangbyexamples.com\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/golangbyexamples.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g\",\"caption\":\"admin\"},\"url\":\"https:\/\/golangbyexamples.com\/author\/admin\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Return JSON body in HTTP response in Go (Golang) - Welcome To Golang By Example","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/","og_locale":"en_US","og_type":"article","og_title":"Return JSON body in HTTP response in Go (Golang) - Welcome To Golang By Example","og_description":"Table of Contents OverviewExample Overview Write method of the ResponseWriter interface in net\/http package can be used to set the JSON body in an HTTP response In GO a response is represented...","og_url":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/","og_site_name":"Welcome To Golang By Example","article_published_time":"2021-07-10T16:56:58+00:00","article_modified_time":"2021-07-10T19:15:37+00:00","author":"admin","twitter_card":"summary_large_image","twitter_misc":{"Written by":"admin","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/","url":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/","name":"Return JSON body in HTTP response in Go (Golang) - Welcome To Golang By Example","isPartOf":{"@id":"https:\/\/golangbyexamples.com\/#website"},"datePublished":"2021-07-10T16:56:58+00:00","dateModified":"2021-07-10T19:15:37+00:00","author":{"@id":"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f"},"breadcrumb":{"@id":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/golangbyexamples.com\/json-response-body-http-go\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/golangbyexamples.com\/json-response-body-http-go\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/golangbyexamples.com\/"},{"@type":"ListItem","position":2,"name":"Return JSON body in HTTP response in Go (Golang)"}]},{"@type":"WebSite","@id":"https:\/\/golangbyexamples.com\/#website","url":"https:\/\/golangbyexamples.com\/","name":"Welcome To Golang By Example","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/golangbyexamples.com\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/golangbyexamples.com\/#\/schema\/person\/8833ea7638dafd763cb1db6c0ca4576f","name":"admin","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/golangbyexamples.com\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g","caption":"admin"},"url":"https:\/\/golangbyexamples.com\/author\/admin\/"}]}},"jetpack_featured_media_url":"","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paOs1b-1xE","amp_validity":null,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts\/5930","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/comments?post=5930"}],"version-history":[{"count":2,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts\/5930\/revisions"}],"predecessor-version":[{"id":5940,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/posts\/5930\/revisions\/5940"}],"wp:attachment":[{"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/media?parent=5930"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/categories?post=5930"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/golangbyexamples.com\/wp-json\/wp\/v2\/tags?post=5930"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}