XML with DOCTYPE Parsing Problem

Does anyone know how to remove the DOCTYPE in XML input file before passing it to the SAX parser using Java? The problem is how to get or trace the input file content which has DOCTYPE in it? Another problem is how to output the content of input XML file in normalized form of XML? It means there would be declarations of namespaces only in the first element of the XML. Each element would have prefixes based on the namespaces it has. If the input file already has elements which have prefixes declared, it will be replaced with the any prefixes as long as matches the namespaces prefixes. I really need help for this. Hope someone is familiar in this. Thanks.