<div class="htmledit_views">                 <p style="line-height:1.55;"></p><h1 style="font-weight:500;color:rgb(51,51,51);font-size:30px;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><br></h1><p style="line-height:1.55;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;">版權所屬：<a href="https://www.sojson.com/" rel="nofollow" style="color:rgb(1,170,237);" target="_blank">SO JSON線上解析</a></p><p style="line-height:1.55;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;">原文地址：<a href="https://www.sojson.com/blog/58.html" rel="nofollow" style="color:rgb(1,170,237);" target="_blank">https://www.sojson.com/blog/58.html</a></p><p class="yellow" style="line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;color:rgb(255,87,34);">轉載時必須以連結形式註明原始出處及本宣告。</p><br><p style="line-height:1.55;"><span style="color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;"><a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">Referer&nbsp;&nbsp;</a>是&nbsp;<a href="http://www.sojson.com/tag_http.html" rel="nofollow" title="HTTP" style="color:rgb(1,170,237);" target="_blank">&nbsp;HTTP&nbsp;&nbsp;</a>請求<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">header</code>&nbsp;的一部分，當瀏覽器（或者模擬瀏覽器行為）向<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">web</code>&nbsp;伺服器傳送請求的時候，頭資訊裡有包含&nbsp;<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>。比如我在</span><span style="font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;color:#c7254e;"><span style="font-size:13.95px;background-color:rgb(249,242,244);">www.google.com</span></span><span style="font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;color:#333333;"><span style="font-size:15px;">&nbsp;裡有一個</span></span><code style="color:rgb(51,51,51);font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;font-size:.93em;">www.baidu.com</code><span style="font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;color:#333333;"><span style="font-size:15px;">&nbsp;連結，那麼點選這個</span></span><code style="color:rgb(51,51,51);font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;font-size:.93em;">www.baidu.com</code><span style="font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;color:#333333;"><span style="font-size:15px;">&nbsp;，它的</span></span><code style="color:rgb(51,51,51);font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;font-size:.93em;">header</code><span style="font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;color:#333333;"><span style="font-size:15px;">&nbsp;資訊裡就有：</span></span></p><p style="line-height:1.55;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;">&nbsp;&nbsp;&nbsp;&nbsp;Referer=http://www.google.com</p><p style="line-height:1.55;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;">由此可以看出來吧。它就是表示一個來源。看下圖的一個請求的<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>資訊。</p><p style="line-height:1.55;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;font-size:15px;"><img src="https://img-blog.csdn.net/20180302212146140?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvc2hlbnF1ZXlpbmc=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70" alt=""><br></p><p style="line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"></p><h3 style="font-size:18px;color:rgb(51,51,51);font-weight:500;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><a name="t1"></a>這裡有一個小問題要說明下。</h3><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">Referer&nbsp;&nbsp;</a>的正確英語拼法是<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">referrer</code>&nbsp;。由於早期HTTP規範的拼寫錯誤，為了保持向後相容就將錯就錯了。其它網路技術的規範企圖修正此問題，使用正確拼法，所以目前拼法不統一。還有它第一個字母是大寫。</p><br><br><h1 style="font-size:30px;color:rgb(51,51,51);font-weight:500;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><a name="t2"></a>Referer的作用？</h1><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">1.防盜鏈。</p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">剛剛前面有提到一個小<a href="http://www.sojson.com/tag_demo.html" rel="nofollow" title="Demo" style="color:rgb(1,170,237);" target="_blank">&nbsp;Demo&nbsp;&nbsp;</a>。</p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">我在www.google.com裡有一個<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">www.baidu.com</code>連結，那麼點選這個<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">www.baidu.com</code>，它的header資訊裡就有：<br></p><blockquote style="font-size:15px;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;border-left:5px solid rgb(208,229,242);line-height:1.4;">Referer=http://www.google.com</blockquote><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">那麼可以利用這個來防止盜鏈了，比如我只允許我自己的網站訪問我自己的圖片伺服器，那我的域名是<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">www.google.com</code>，那麼圖片伺服器每次取到Referer來判斷一下是不是我自己的域名<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">www.google.com</code>，如果是就繼續訪問，不是就攔截。</p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">這是不是就達到防盜鏈的效果了？</p><p style="line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><span style="font-size:24px;color:#cc0000;"><strong><u>將這個http請求發給伺服器後，如果伺服器要求必須是某個地址或者某幾個地址才能訪問，而你傳送的referer不符合他的要求，就會攔截或者跳轉到他要求的地址，然後再通過這個地址進行訪問。</u></strong></span></p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">2.防止惡意請求。</p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">比如靜態請求是<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">*.html</code>結尾的，動態請求是<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">*.shtml</code>，那麼由此可以這麼用，所有的<code style="font-size:.93em;font-family:Menlo, Monaco, Consolas, 'Courier New', monospace;">*.shtml</code>請求，必須<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>為我自己的網站。</p><blockquote style="font-size:15px;color:rgb(51,51,51);font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;border-left:5px solid rgb(208,229,242);line-height:1.4;"><p style="line-height:1.55;">Referer=http://www.google.com</p></blockquote><h1 style="font-size:30px;color:rgb(51,51,51);font-weight:500;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><a name="t3"></a>空Referer是怎麼回事？什麼情況下會出現Referer?</h1><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">首先，我們對空<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>的定義為，<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>頭部的內容為空，或者，一個<a href="http://www.sojson.com/tag_http.html" rel="nofollow" title="HTTP" style="color:rgb(1,170,237);" target="_blank">&nbsp;HTTP&nbsp;&nbsp;</a>請求中根本不包含<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>頭部。</p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">那麼什麼時候<a href="http://www.sojson.com/tag_http.html" rel="nofollow" title="HTTP" style="color:rgb(1,170,237);" target="_blank">&nbsp;HTTP&nbsp;&nbsp;</a>請求會不包含<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>欄位呢？根據Referer的定義，它的作用是指示一個請求是從哪裡連結過來，那麼當一個請求並不是由連結觸發產生的，那麼自然也就不需要指定這個請求的連結來源。</p><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">比如，直接在瀏覽器的位址列中輸入一個資源的URL地址，那麼這種請求是不會包含<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>欄位的，因為這是一個“憑空產生”的<a href="http://www.sojson.com/tag_http.html" rel="nofollow" title="HTTP" style="color:rgb(1,170,237);" target="_blank">&nbsp;HTTP&nbsp;&nbsp;</a>請求，並不是從一個地方連結過去的。<br></p><h3 style="font-size:18px;color:rgb(51,51,51);font-weight:500;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;"><a name="t4"></a>那麼在防盜鏈設定中，允許空Referer和不允許空Referer有什麼區別？</h3><p style="font-size:15px;color:rgb(51,51,51);line-height:1.55;font-family:PingFangSC, 'helvetica neue', 'hiragino sans gb', arial, 'microsoft yahei ui', 'microsoft yahei', simsun, sans-serif;">允許<a href="http://www.sojson.com/tag_referer.html" rel="nofollow" title="Referer" style="color:rgb(1,170,237);" target="_blank">&nbsp;Referer&nbsp;&nbsp;</a>為空，意味著你允許比如瀏覽器直接訪問，就是空。</p>            </div>