Using Matcher to extract URL domain name - regex

Question

static String AdrPattern="http://www.([^&]+)\\.com\\.*";
static Pattern WebUrlPattern = Pattern.compile (AdrPattern);
static Matcher WebUrlMatcher;
WebUrlMatcher = WebUrlPattern.matcher ("keyword");
if(WebUrlMatcher.matches())
String extractedPath = WebUrlMatcher.group (1);
Considering above codes, My aim is to extract the domain name from the URL and dismiss the rest. But the trouble is that, first of all, if the URL has deeper path, it will not ignore it and second, it does not work for all URL with .com extension.
For example, if the URL is http://www.lego.com/en-us/technic/?domainredir=technic.lego, the result will not be lego but lego.com/en-us/technic/?domainredir=technic.lego.

Answer 1

Use
static String AdrPattern="http://www\\.([^&]+)\\.com.*";
^^ ^
You escaped the final dot, and it was treated as a literal, and matches could not match the entire string. Also, the first dot must be escaped.
Also, to make the regex a bit more strict, you can replace the [^&]+ with [^/&].
UPDATE:
static String AdrPattern="http://www\\.([^/&]+)\\.com/([^/]+)/([^/]+)/([^/]+).*";
static Pattern WebUrlPattern = Pattern.compile (AdrPattern);
static Matcher WebUrlMatcher = WebUrlPattern.matcher("http://www.lego.com/en-us/technic/?domainredir=technic.lego");
if(WebUrlMatcher.matches()) {
String extractedPath = WebUrlMatcher.group(1);
String extractedPart1 = WebUrlMatcher.group(2);
String extractedPart2 = WebUrlMatcher.group(3);
String extractedPart3 = WebUrlMatcher.group(4);
}
Or, with \G:
static String AdrPattern="(?:http://www\\.([^/&]+)\\.com/|(?!^)\\G)/?([^/]+)";
static String AdrPattern="http://www\\.([^/&]+)\\.com/([^/]+)/([^/]+)/([^/]+)";
static Pattern WebUrlPattern = Pattern.compile (AdrPattern);
static Matcher WebUrlMatcher = WebUrlPattern.matcher("http://www.lego.com/en-us/technic/?domainredir=technic.lego");
int cnt = 0;
while(WebUrlMatcher.find()) {
if (cnt == 0) {
String extractedPath = WebUrlMatcher.group(1);
String extractedPart = WebUrlMatcher.group(2);
cnt = cnt + 1;
}
else {
String extractedPart = WebUrlMatcher.group(2);
}
}