xml validation with local dtd passing local xml and dtd files using java

Question

I have found a lot of examples like this:

    public static boolean validateXMLSchema(String xsdPath, String xmlPath){

        try {
            SchemaFactory factory =
                    SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            Schema schema = factory.newSchema(new File(xsdPath));
            Validator validator = schema.newValidator();
            validator.validate(new StreamSource(new File(xmlPath)));
        } catch (IOException | SAXException e) {
            System.out.println("Exception: "+e.getMessage());
            return false;
        }
        return true;
    }
}

showing how to validate xml files over xsd, and I figured out that it's not so easy to do the same using dtd files. I have a bunch of xml files using different types of dtd (dtd files are in another location) with format:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE name SYSTEM "name.dtd">
<name>

  .
  .
  .

</name>

How should I validate, similarly as with example above, using dtd (passing local xml and dtd paths)?

Answer 1

If you use a SAX parser, you may want to look into the org.xml.sax.EntityResolver interface. You create a class that implements this interface and call .setEntityResolver(yourResolver) on your XMLReader . Most SAX Parsers will validate your XML automatically if a DTD is available, otherwise you may have to set the validation feature to true .