从网址获取元数据

Question

I have used Jsoup library to fetch the metadata from url.

Document doc = Jsoup.connect("http://www.google.com").get();  
String keywords = doc.select("meta[name=keywords]").first().attr("content");  
System.out.println("Meta keyword : " + keywords);  
String description = doc.select("meta[name=description]").get(0).attr("content");  
Elements images = doc.select("img[src~=(?i)\\.(png|jpe?g|gif)]");  

String src = images.get(0).attr("src");
System.out.println("Meta description : " + description); 
System.out.println("Meta image URl : " + src);

But I want to do it in client side using javascript

Answer 1

You can't do it client only because of the cross-origin issue. You need a server side script to get the content of the page.

OR You can use YQL. In this way, the YQL will used as proxy. _{https://policies.yahoo.com/us/en/yahoo/terms/product-atos/yql/index.htm}

Or you can use https://cors-anywhere.herokuapp.com. In this way, cors-anywhere will used as proxy:

For example:

$('button').click(function() {
  $.ajax({
    url: 'https://cors-anywhere.herokuapp.com/' + $('input').val()
  }).then(function(data) {
    var html = $(data);

    $('#kw').html(getMetaContent(html, 'description') || 'no keywords found');
    $('#des').html(getMetaContent(html, 'keywords') || 'no description found');
    $('#img').html(html.find('img').attr('src') || 'no image found');
  });
});

function getMetaContent(html, name) {
  return html.filter(
  (index, tag) => tag && tag.name && tag.name == name).attr('content');
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<input type="text" placeholder="Type URL here" value="http://www.html5rocks.com/en/tutorials/cors/" />
<button>Get Meta Data</button>

<pre>
  <div>Meta Keyword: <div id="kw"></div></div>
  <div>Description: <div id="des"></div></div>
  <div>image: <div id="img"></div></div>
</pre>

</div>