How to validate a XML document from a XML schema using javax.xml.validation.Validator

Since 1.5, you can validate a XML document from a XML schema using the javax.xml.validation.Validator object.

Here's a snippet of code showing how to use this validator.

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;

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

import org.w3c.dom.Document;
import org.xml.sax.SAXException;


public class Main {

  /**
   * Will throw a SAXException if the XML document is not valid
   * @param args
   * @throws ParserConfigurationException
   * @throws IOException
   * @throws SAXException
  */
  public static void main(String[] args) throws ParserConfigurationException,
     SAXException, IOException {
  
     String xml = "...";
      
     //XML parsing
     DocumentBuilderFactory docBuilderfactory = DocumentBuilderFactory.newInstance();
     DocumentBuilder builder = docBuilderfactory.newDocumentBuilder();
 
     InputStream is = new ByteArrayInputStream(xml.getBytes());
     Document xmlDocument = builder.parse(is);
     xmlDocument.getDocumentElement().normalize();
      
     //XSD parsing
     File xsd = new File("src/main/resources/xsd/yourXsd.xsd");
     SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
     Schema schema = schemaFactory.newSchema(xsd);
      
     //Validation
     javax.xml.validation.Validator validator = schema.newValidator();
     Source source = new DOMSource(xmlDocument);
     validator.validate(source);
  }
}

This validator is very verbose. In a real application, a good practice is to create a component encapsulating the code above.