How to parse an HTTP file

Hi.

I'm trying to parse a HTTP file
http://www.foo.com/foo.xml

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use XML::Xerces;

my $file  = XML::Xerces::LocalFileInputSource->new("http://www.foo.com/foo.xml");
my $parser = XML::Xerces::XercesDOMParser->new();
eval { $parser->parse($file); };
error($@,"Couldn't parse file: $ARGV[0]") if $@;
my $doc = $parser->getDocument();
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But I'm not able. I get this error message:
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Can't call method "getDocumentElement" on an undefined value at
parse_url.pl line 7.
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What am I doing wrong? Thank you very much.