{"id":5876,"date":"2021-07-10T12:49:49","date_gmt":"2021-07-10T07:19:49","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=5876"},"modified":"2021-07-10T16:49:57","modified_gmt":"2021-07-10T11:19:57","slug":"404-http-status-code-golang","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/404-http-status-code-golang\/","title":{"rendered":"Return 404 (Resource Not Found) Status Code 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\/404-http-status-code-golang\/#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\/404-http-status-code-golang\/#Program\" title=\"Program\">Program<\/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>Overview<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"has-medium-font-size\">http package of golang provides the status code constant which could be used to return different status codes- <a href=\"https:\/\/golang.org\/src\/net\/http\/status.go\">https:\/\/golang.org\/src\/net\/http\/status.go<\/a><\/p>\n\n\n\n<p class=\"has-medium-font-size\">The same can also be used to return the 404 (Resource Not Found) http status code. The http 404 status code is defined by the below constant<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">http.StatusNotFound<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">In this article, we will also see how to return a JSON body along with the 404 (Resource Not Found) http status code<\/p>\n\n\n\n<h2 class=\"has-luminous-vivid-orange-color has-text-color wp-block-heading\"><span class=\"ez-toc-section\" id=\"Program\"><\/span><strong>Program<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\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.StatusNotFound)\n\tw.Header().Set(\"Content-Type\", \"application\/json\")\n\tresp := make(map[string]string)\n\tresp[\"message\"] = \"Resource Not Found\"\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\">Here we are using the <strong>WriteHeader<\/strong> function to specify the 404 http status code and uses the <strong>Write<\/strong> function to also return the response bodyThe above code returns the below JSON request body back in response<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">{\"message\":\"Resource Not Found\"}<\/code><\/pre>\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\/1.1 404 Not Found\n< Date: Sat, 10 Jul 2021 06:18:12 GMT\n< Content-Length: 32\n< Content-Type: text\/plain; charset=utf-8\n< \n* Connection #0 to host localhost left intact\n{\"message\":\"Resource Not Found\"}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">As you can see from the output, it correctly returns the <strong>404<\/strong> status code along with the body.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">You can also directly pass 404 to the <strong>WriteHeader<\/strong> function to send the 404 response.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">w.WriteHeader(404)<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">This also works correctly. Try it out.<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><strong>net\/http<\/strong> package of golang also provides a <strong>\"NotFound\"<\/strong> handler that could be used to return a 404 for a particular API every time.<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><a href=\"https:\/\/golang.org\/pkg\/net\/http\/#NotFound\">https:\/\/golang.org\/pkg\/net\/http\/#NotFound<\/a><\/p>\n\n\n\n<p class=\"has-medium-font-size\">This handler function return 404 status and below response body<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">404 page not found<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Below is the simple 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\"net\/http\"\n)\n\nfunc main() {\n\thttp.HandleFunc(\"\/example\", http.NotFound)\n\thttp.ListenAndServe(\":8080\", nil)\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">In the above program, we simply specified the NotFound handler for <strong>localhost:8080\/example<\/strong> API as below<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">http.HandleFunc(\"\/example\", http.NotFound)<\/code><\/pre>\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<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\/1.1 404 Not Found\n< Content-Type: text\/plain; charset=utf-8\n< X-Content-Type-Options: nosniff\n< Date: Sat, 10 Jul 2021 06:23:41 GMT\n< Content-Length: 19\n< \n404 page not found\n* Connection #0 to host localhost left intact<\/code><\/pre>\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 OverviewProgram Overview http package of golang provides the status code constant which could be used to return different status codes- https:\/\/golang.org\/src\/net\/http\/status.go The same can also be used to return&#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":[330,3,4],"class_list":["post-5876","post","type-post","status-publish","format-standard","hentry","category-tech","tag-330","tag-go","tag-golang"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - 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