PHP无法获取Referer有关问题排查

<?phpecho <span class="str">'测试来源：直接载入页面<br/>'</span>;echo <span class="str">'<a href="test_cookie.php">进入页面</a><br/>'</span>;echo <span class="str">'测试来源：新窗口打开<br/>'</span>;echo <span class="str">'<a target="_blank" href="test_cookie.php">进入页面</a><br/>'</span>;

<?phpdate_default_timezone_set(<span class="str">'Asia/Shanghai'</span>);<span class="rem">//设置默认时区</span>header(<span class="str">'content-type:text/html; charset=utf8'</span>);<span class="rem">//设置返回头信息</span>echo date(<span class="str">'Y-m-d H:i:s'</span>);echo <span class="str">"<br/>\r\n"</span>;echo <span class="str">'PHP获取Refer是：'</span>;$refer=isset($_SERVER[<span class="str">'HTTP_REFERER'</span>])?$_SERVER[<span class="str">'HTTP_REFERER'</span>]:<span class="str">'No refer found'</span>;echo $refer;echo <span class="str">"<br/>\r\n"</span>;echo <span class="str">'JS获取Refer是：'</span>;    echo <span class="str">"<script>document.writeln(document.referrer);</script>"</span>;echo <span class="str">"<br/>\r\n"</span>;