Serve Compressed Javascript

<p>If your client side web app has lots of javascript files, here is the basic code to serve them as a single compressed file. For testing, include links for each js file (in index.html), then for production comment out those lines and include 1 line for the merged/compressed js file. This method will also return a &#34;304 Not Modified&#34; if the client already has the current version of the code. </p> <pre><code>codeFiles := []string{&#34;code1.js&#34;, &#34;code2.js&#34;, &#34;code3.js&#34;} fileOut, _ := os.Create(&#34;codejs.gzip&#34;) compressor := gzip.NewWriter(fileOut) for _, file := range codeFiles { fileIn, _ := os.Open(file) io.Copy(compressor, fileIn) fileIn.Close() } compressor.Close() fileOut.Close() modTime := time.Now() codeFile, _ := os.Open(&#34;codejs.gzip&#34;) defer codeFile.Close() // url does not have to match actual file name, in html use &lt;script src=&#34;code.js&#34; ... http.HandleFunc(&#34;/code.js&#34;, func(w http.ResponseWriter, r *http.Request) { w.Header().Set(&#34;Content-Type&#34;, &#34;application/javascript&#34;) w.Header().Set(&#34;Content-Encoding&#34;, &#34;gzip&#34;) http.ServeContent(w, r, &#34;&#34;, modTime, codeFile) }) http.ListenAndServe(&#34;:http&#34;, nil) </code></pre> <hr/>**评论：**<br/><br/>BitWarrior: <pre><p>Being that <code>modTime</code> is being set on execution, wouldn&#39;t the mod time always return the current time, thus the client always will request a new file?</p></pre>jayposs: <pre><p>No, modTime is set when the app loads. Typically the app will run for a long time (like weeks). Of course you can use some other logic for setting this value.</p></pre>BitWarrior: <pre><p>You have the opportunity to take the md5 value of your concatenated file and produce an etag out of it. You would get more accurate and potentially longer lived caching out of the deal.</p></pre>jayposs: <pre><p>Sounds like a good idea. I&#39;ll have to get the details on how to get the md5 value.</p></pre>