Given such a domain:
http%3a%2f%2fwww.google.com%2fpagead%2fconversion%2f1001680686%2f%3flabel%3d4dahCKKczAYQrt7R3QM%26value%3d%26muid%3d_0RQqV8nf-ENh3b4qRJuXQ%26bundleid%3dcom.google.android.youtube%26appversion%3d5.10
I want to replace the
%3a%2f%2
with
://
and get rid all the content behind ".com", so finally I just want to got
http://www.google.com
How can I implement this in Java using a regex?
You can use:
String u = URLDecoder.decode(url, "UTF-8").replaceFirst("(\\.[^/]+).*$", "$1");
// http://www.google.com
\\. and then using negation regex [^/]+ it matches text until it hits a slash /. (\\.[^/]+) is capturing this in captured group #1 and .*$ matches everything till end of URL. In the replacement part we just a back reference $1 for captured group #1 thus giving us http://nfl.demdex.net and discarding the rest.So you have a URL of this scheme after you decoded it (e.g. with java.net.URLDecoder.decode()):
http://www.google.com/here/is/some/content
To get the Domain and the Protocol from the input, you can use a regex like this:
String input = URLDecoder.decode("http%3a%2f%2fwww.google.com%2fpagead%2fconversion%2f1001680686%2f%3flabel%3d4dahCKKczAYQrt7R3QM%26value%3d%26muid%3d_0RQqV8nf-ENh3b4qRJuXQ%26bundleid%3dcom.google.android.youtube%26appversion%3d5.10");
Matcher m = Pattern.compile("(http[s]?)://([^/]+)(/.*)?").matcher(input);
if (!m.matches()) return;
String protocol = m.group(1);
String domain = m.group(2);
System.out.println(protocol + "://" + domain);
Explanation of the regex:
(http[s]?)://([^/]+)(/.*)?
|---1----|-2-|--3--|--4---|
http and https[^/]+ is any string that doesn't contain a slash)One way;
java.net.URI uri = new java.net.URI(java.net.URLDecoder.decode(url, "UTF-8"));
System.out.println( uri.getScheme() + "://" + uri.getHost() );
