177 lines
7.4 KiB
Plaintext
Generated
177 lines
7.4 KiB
Plaintext
Generated
<!DOCTYPE html>
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<html>
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<head>
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<meta charset="utf-8">
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<title>Go by Example: HTTP Clients</title>
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<link rel=stylesheet href="site.css">
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</head>
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<script>
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onkeydown = (e) => {
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if (e.key == "ArrowLeft") {
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window.location.href = 'environment-variables';
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}
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if (e.key == "ArrowRight") {
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window.location.href = 'http-servers';
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}
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}
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</script>
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<body>
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<div class="example" id="http-clients">
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<h2><a href="./">Go by Example</a>: HTTP Clients</h2>
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<table>
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<tr>
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<td class="docs">
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<p>The Go standard library comes with excellent support
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for HTTP clients and servers in the <code>net/http</code>
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package. In this example we’ll use it to issue simple
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HTTP requests.</p>
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</td>
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<td class="code leading">
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<a href="http://play.golang.org/p/VxYIifr_UuH"><img title="Run code" src="play.png" class="run" /></a><img title="Copy code" src="clipboard.png" class="copy" />
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<div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
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<span class="s">"bufio"</span>
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<span class="s">"fmt"</span>
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<span class="s">"net/http"</span>
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<span class="p">)</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code leading">
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<div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Issue an HTTP GET request to a server. <code>http.Get</code> is a
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convenient shortcut around creating an <code>http.Client</code>
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object and calling its <code>Get</code> method; it uses the
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<code>http.DefaultClient</code> object which has useful default
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settings.</p>
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</td>
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<td class="code leading">
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<div class="highlight"><pre> <span class="nx">resp</span><span class="p">,</span> <span class="nx">err</span> <span class="o">:=</span> <span class="nx">http</span><span class="p">.</span><span class="nx">Get</span><span class="p">(</span><span class="s">"http://gobyexample.com"</span><span class="p">)</span>
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<span class="k">if</span> <span class="nx">err</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
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<span class="nb">panic</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
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<span class="p">}</span>
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<span class="k">defer</span> <span class="nx">resp</span><span class="p">.</span><span class="nx">Body</span><span class="p">.</span><span class="nx">Close</span><span class="p">()</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Print the HTTP response status.</p>
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</td>
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<td class="code leading">
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<div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"Response status:"</span><span class="p">,</span> <span class="nx">resp</span><span class="p">.</span><span class="nx">Status</span><span class="p">)</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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<p>Print the first 5 lines of the response body.</p>
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</td>
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<td class="code leading">
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<div class="highlight"><pre> <span class="nx">scanner</span> <span class="o">:=</span> <span class="nx">bufio</span><span class="p">.</span><span class="nx">NewScanner</span><span class="p">(</span><span class="nx">resp</span><span class="p">.</span><span class="nx">Body</span><span class="p">)</span>
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<span class="k">for</span> <span class="nx">i</span> <span class="o">:=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">scanner</span><span class="p">.</span><span class="nx">Scan</span><span class="p">()</span> <span class="o">&&</span> <span class="nx">i</span> <span class="p"><</span> <span class="mi">5</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span> <span class="p">{</span>
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<span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="nx">scanner</span><span class="p">.</span><span class="nx">Text</span><span class="p">())</span>
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<span class="p">}</span>
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</pre></div>
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</td>
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</tr>
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<tr>
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<td class="docs">
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</td>
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<td class="code">
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<div class="highlight"><pre> <span class="k">if</span> <span class="nx">err</span> <span class="o">:=</span> <span class="nx">scanner</span><span class="p">.</span><span class="nx">Err</span><span class="p">();</span> <span class="nx">err</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
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<span class="nb">panic</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
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<span class="p">}</span>
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<span class="p">}</span>
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</pre></div>
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</td>
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</tr>
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</table>
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<table>
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<tr>
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<td class="docs">
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</td>
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<td class="code">
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<div class="highlight"><pre><span class="gp">$</span> go run http-clients.go
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<span class="go">Response status: 200 OK</span>
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<span class="go"><!DOCTYPE html></span>
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<span class="go"><html></span>
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<span class="go"> <head></span>
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<span class="go"> <meta charset="utf-8"></span>
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<span class="go"> <title>Go by Example</title></span>
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</pre></div>
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</td>
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</tr>
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</table>
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<p class="next">
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Next example: <a href="http-servers">HTTP Servers</a>.
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</p>
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<p class="footer">
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by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/http-clients">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
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</p>
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</div>
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<script>
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var codeLines = [];
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codeLines.push('package main\u000A');codeLines.push('import (\u000A \"bufio\"\u000A \"fmt\"\u000A \"net/http\"\u000A)\u000A');codeLines.push('func main() {\u000A');codeLines.push(' resp, err := http.Get(\"http://gobyexample.com\")\u000A if err != nil {\u000A panic(err)\u000A }\u000A defer resp.Body.Close()\u000A');codeLines.push(' fmt.Println(\"Response status:\", resp.Status)\u000A');codeLines.push(' scanner := bufio.NewScanner(resp.Body)\u000A for i := 0; scanner.Scan() && i \x3C 5; i++ {\u000A fmt.Println(scanner.Text())\u000A }\u000A');codeLines.push(' if err := scanner.Err(); err != nil {\u000A panic(err)\u000A }\u000A}\u000A');codeLines.push('');
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</script>
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<script src="site.js" async></script>
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</body>
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</html>
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