获取网站icon，常用最简单的方法就是通过website/favicon.ico来获取，不过由于很多网站都是在页面里面设置favicon，所以此方法很多情况都不可用。
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<style type="text/css">
#input {
height: 300px;
padding: 10px 5px;
line-height: 20px;
width: 1000px;
}
#submit {
height: 30px;
text-align: center;
color: #ffffff;
line-height: 30px;
width: 80px;
background-color: blue;
margin-top: 20px;
}
#result {
margin-top: 20px;
}
#result li {
height: 40px;
line-height: 40px;
float: left;
margin: 10px 14px;
}
</style>
</head>
<body>
<textarea id="input" placeholder="输入多个网址以空格间隔"></textarea>
<div id="submit">获取icon</div>
<ul id="result">
</ul>
<script type="text/javascript">
var input = document.getElementById("input");
var submit = document.getElementById("submit");
var result = document.getElementById("result");
var val;
function trim(str) {
var whitespace = ' \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000';
for (var i = 0, len = str.length; i < len; i++) {
if (whitespace.indexOf(str.charAt(i)) === -1) {
str = str.substring(i);
break;
}
}
for (i = str.length - 1; i >= 0; i--) {
if (whitespace.indexOf(str.charAt(i)) === -1) {
str = str.substring(0, i + 1);
break;
}
}
return whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
}
function getFavIconUrl(url) {
var prohost;
prohost = url.match(/([^:\/?#]+:\/\/)?([^\/@:]+)/i);
prohost = prohost ? prohost : [true, "http://", document.location.hostname];
//补全url
if (!prohost[1]) {
prohost[1] = "http://";
}
//抓取ico
return "http://www.google.com/s2/favicons?domain=" + prohost[1] + prohost[2];
}
submit.onclick = function() {
val = input.value;
if (!val) alert("输入为空！");
val = val.split(" ");
val.forEach(function(item) {
item = trim(item);
if (!item) return;
result.innerHTML += "<li>" + item + "<img src='" + getFavIconUrl(item) + "'></li>";
});
};
</script>
</body>
</html>
