14 - strange "unknown host" error

[joshsh]

Occasionally, an attempt to dereference an HTTP URI will fail for what
appears to be the wrong reason.  For example, the
<http://www.sw-app.org/foaf/mic.rdf#mic> points to an RDF/XML document
which is served as text/xml (which is not accepted by LinkedDataSail), but
in at least one instance, the dereferencer failed not with a BadMediaType
error, but with an UnknownHostException at the HTTP client level.  That's
strange because the host in question definitely does exist.  I noticed this
 error repeatedly with different hosts which do in fact exist.

2008-04-24 11:57:08,210 [Thread-10] INFO WebClosure - Dereferencing URI
<http://www.sw-app.org/foaf/mic.rdf#mic>
2008-04-24 11:57:54,885 [Thread-10] ERROR RippleException -
java.net.UnknownHostException: www.sw-app.org
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:430)
        at java.net.Socket.connect(Socket.java:520)
        at java.net.Socket.connect(Socket.java:470)
        at java.net.Socket.<init>(Socket.java:367)
        at java.net.Socket.<init>(Socket.java:240)
        at
org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket(DefaultProtocolSocketFactory.java:80)
        at
org.apache.commons.httpclient.protocol.ControllerThreadSocketFactory$1.doit(ControllerThreadSocketFactory.java:91)
        at
org.apache.commons.httpclient.protocol.ControllerThreadSocketFactory$SocketTask.run(ControllerThreadSocketFactory.java:158)
        at java.lang.Thread.run(Thread.java:613)

Original link: http://code.google.com/p/ripple/issues/detail?id=14