XML Validation using custom DTD file

Question

Well, I thought that my problem is about to be a trivial one, but now, I don't think so. I have to develop XML-based protocol over HTTP. XML Document doesn't contain any reference to DTD, but I have some DTDs. I want to validate my XML messages in real time and I want to find some library that allows to do something like that:
SomeXmlValidatingParser s = new SomeXmlValidatingParser(InputStream dtdFileStream);
for(;;)
    InputStream is = message.recive();
    DocumentObject = s.parseAndValidate(is);
}So, the issue is to pass my custom DTD file (it is already loaded to memory) into validating parser.
So, which library have such functionality? And if there are some, could you be so kind to advice some of them?

Answer 1

Well, I've just realized that JDK 1.5 has standard way to validate XMLs using XSD schemas. Ok. But look at the sample
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:import namespace="http://www.w3.org/XML/1998/namespace"
        schemaLocation="http://www.w3.org/2001/xml.xsd" />
  <xs:element name="birthdate">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="month" type="xs:string" />
        <xs:element name="day" type="xs:int" />
        <xs:element name="year" type="xs:int" />
      </xs:sequence> 
    </xs:complexType>
  </xs:element>
</xs:schema>Every time I process this schema, it goes to w3c.org... And I wonder if it cause some problems if I delete
  <xs:import namespace="http://www.w3.org/XML/1998/namespace"
        schemaLocation="http://www.w3.org/2001/xml.xsd" />