XML Validate with DTD

Wikipedia Document Type Definition
W3C Document Type Definition

import java.io.ByteArrayInputStream;
import java.io.InputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;


public class Main implements ErrorHandler {

  public void error(SAXParseException exception) throws SAXException {
    throw exception;    
  }

  public void fatalError(SAXParseException exception) throws SAXException {
    throw exception;        
  }

  public void warning(SAXParseException exception) throws SAXException {
    throw exception;        
  }

  public static void main(String[] args) throws Exception {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    factory.setNamespaceAware(true);
    factory.setValidating(true);
    DocumentBuilder builder = factory.newDocumentBuilder();
    ErrorHandler errorHandler = new Main();
    builder.setErrorHandler(errorHandler);
    StringBuilder sb = new StringBuilder();
    sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>")
        .append("<!DOCTYPE root [")
        .append("<!ELEMENT root (user)>")
        .append("<!ELEMENT user (name,birthday,address)>")
        .append("<!ELEMENT name (#PCDATA)>")
        .append("<!ELEMENT birthday (#PCDATA)>")        
        .append("]>")
        .append("<root>")
        .append("<user>")
        .append("<name>Solnone</name>")
        .append("<birthday>1974-01-01</birthday>")          
        .append("</user>")        
        .append("</root>");
    byte[] buf = sb.toString().getBytes("UTF-8");
    InputStream is = new ByteArrayInputStream(buf);
    try {   
      builder.parse(is);
    } finally {
      is.close();
    }   
  } 
}