+* File UriSchemeNameMatcher.java
+*----------------------------------------------------------------------------*/
+
+package org.alfresco.repo.avm.util;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.List;
+
+import org.alfresco.util.NameMatcher;
+
+/**
+ * A NameMatcher that matches an incoming URL against list of schemes
+ * (less formally known as "protocols"), case insensitively.
+ * The formal spec for parsing URIs is RFC-3986
+ *
+ * Perhaps someday, it might be worthwhile to create a specific
+ * parser for each registered scheme-specific part, and validate
+ * that; for now, we'll just be be more lax, and assume the URI
+ * is alwasy scheme-qualified. This matcher will look no further
+ * than the leading colon, and declare "no match" otherwise.
+ * The discussion below explains why.
+ *
+ * See: http://tools.ietf.org/html/rfc3986):
+ *
+ * The following regex parses URIs:
+ * ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+ *
+ * Given the following URI:
+ * http://www.ics.uci.edu/pub/ietf/uri/#Related
+ *
+ * The captured subexpressions are:
+ *
+ * $1 = http:
+ * $2 = http
+ * $3 = //www.ics.uci.edu
+ * $4 = www.ics.uci.edu
+ * $5 = /pub/ietf/uri/
+ * $6 =
+ * $7 =
+ * $8 = #Related
+ * $9 = Related
+ *
+ * N0TE:
+ * A URI can be non-scheme qualified because $1 is optional. Therefore,
+ * the following are all exaples of valid non-scheme qualified URIS:
+ *
+ * ""
+ * "moo@cow.com"
+ * "moo@cow.com?wow"
+ * "moo@cow.com?wow#zow"
+ * "moo@cow.com#zow"
+ * "/"
+ * "/moo/cow"
+ * "/moo/cow?wow"
+ * "/moo/cow?wow#zow"
+ * "/moo/cow#zow"
+ * "//moo/cow"
+ * "//moo.com/cow"
+ * "//moo.com/cow/"
+ * "//moo.com/cow?wow"
+ * "//moo.com/cow?wow#zow"
+ * "//moo.com/cow#zow"
+ * "//moo.com:8080/cow"
+ * "//moo.com:/cow"
+ * "//moo.com:8080/cow?wow"
+ * "//moo.com:8080/cow?wow#zow"
+ * "//moo.com:8080/cow#zow"
+ * "///moo/cow"
+ * "///moo/cow?wow"
+ * "///moo/cow?wow#zow"
+ * "///moo/cow#zow"
+ *
+ * And so forth...
+ *
+ *
+ *
+ * Thus the business end of things as far as scheme matching is: $2,
+ * Most schemes will have a $3 that starts with '//', but not all.
+ * Specificially, the following have no "network path '//' segment,
+ * or aren't required to (source: http://en.wikipedia.org/wiki/URI_scheme):
+ *
+ *
+ * cid data dns fax go h323 iax2 mailto mid news pres sip
+ * sips tel urn xmpp about aim callto feed magnet msnim
+ * psyc skype sms stream xfire ymsgr
+ *
+ *
+ *
+ * Visually the parts are as follows:
+ *
+ *
+ * foo://example.com:10042/over/there?name=ferret#nose
+ * \_/ \_______________/\_________/ \_________/ \__/
+ * | | | | |
+ * scheme authority path query fragment
+ * | _____________________|__
+ * / \ / \
+ * urn:example:animal:ferret:nose
+ *
+ *
+ *
+ * This is useful for classifying URLs for things like whether or not
+ * they're supported by an application.
+ *
+ * For example, the LinkValidationService supports http, and https,
+ * is willing to ignore certain well-formed URLs, but treats URLs
+ * will unknown and unsupported protocols as broken. Concretely,
+ * we'd like to avoid treating something like the following one
+ * as being non-broken even though you can't apply GET or HEAD
+ * to it.
+ *
+ *
+ * Email
+ *
+ *
+ * As of June 2007,IANA had over 70 registered and provisional protocols
+ * listed at http://www.iana.org/assignments/uri-schemes.html but sometimes
+ * people create their own too (e.g.: cvs). Here's the official list:
+ *
+ *
+ * aaa aaas acap afs cap cid crid data dav dict dns dtn fax file
+ * ftp go gopher h323 http https iax2 icap im imap info ipp iris
+ * iris.beep iris.lwz iris.xpc iris.xpcs ldap mailserver mailto
+ * mid modem msrp msrps mtqp mupdate news nfs nntp opaquelocktoken
+ * pop pres prospero rtsp service shttp sip sips snmp soap.beep
+ * soap.beeps tag tel telnet tftp thismessage tip tn3270 tv urn
+ * vemmi wais xmlrpc.beep xmlrpc.beeps xmpp z39.50r z39.50s
+ *
+ *
+ */
+public class UriSchemeNameMatcher implements NameMatcher, Serializable
+{
+ /**
+ * The extensions to match.
+ */
+ HashMap scheme_;
+
+ /**
+ * Default constructor.
+ */
+ public UriSchemeNameMatcher()
+ {
+ scheme_ = new HashMap();
+ }
+
+ /**
+ * Set the protocols case insensitively (cannonicalized to lower-case).
+ *
+ * @param protocols
+ */
+ public void setExtensions(List protocols)
+ {
+ for (String protocol : protocols)
+ {
+ scheme_.put( protocol.toLowerCase(), null );
+ }
+ }
+
+ /**
+ * Returns true if the URL's protocol is in the of
+ * being matched. Everything up to but not including
+ * the intial colon is
+ */
+ public boolean matches(String uri)
+ {
+ if ( uri == null ) { return false; }
+
+ int colon_index = uri.indexOf(':');
+
+ if ( colon_index >= 0)
+ {
+ String proto =
+ uri.substring(0, colon_index).toLowerCase();
+
+ return scheme_.containsKey( proto );
+ }
+ return false;
+ }
+}
+