Validate XML against XSD

Hi I was trying to validate a XML document against XSD.

Everything is fine if that XSD is a very simple XSD. But if my XSD includes some other XSD's also as mentioned below as an example this program is not functioning.

<xs:include schemaLocation="ABC.xsd"

I am also attaching code which I used to validate.

package test;

import java.io.File;

import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;

import org.w3c.dom.Document;

public class XMLValidation {
  public static void main(String[] args) {
    try {
      validate();
    } catch (Exception e) {
      e.printStackTrace();
      // TODO Auto-generated catch block e.printStackTrace();
    }
  }

private static void validate() throws Exception {
    // build an XSD-aware SchemaFactory
    SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

// hook up org.xml.sax.ErrorHandler implementation.
    // schemaFactory.setErrorHandler( System.err );

// get the custom xsd schema describing the required format for my XML files.
    Schema schemaXSD = schemaFactory.newSchema(new File("xsd/Main.xsd"));

// Create a Validator capable of validating XML files according to my custom schema.
    Validator validator = schemaXSD.newValidator();

// Get a parser capable of parsing vanilla XML into a DOM tree
    DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();

// parse the XML purely as XML and get a DOM tree represenation.
    Document document = parser.parse(new File("xsd/main.xml"));

// parse the XML DOM tree againts the stricter XSD schema
    validator.validate(new DOMSource(document));
  }
}

Could anyone let me know, if I need to use something else to validate XML against complex XSD's. Any insight would be appreciated.>