XML with XSD JAVA

Question

Hi All,

I have been assigned a work to validate a XML against an XSD and if everthing passed will parse the XML so that can import the same in to my system.

My Qyestion is whats the best way to validate an XML against the XSD and which is the best API for parsing the XML in to my domain object.

Looking for valuable suggestions

Thnaks in advance

Answer 1

JAXB is the Java standard XML parsing library: http://www.oracle.com/technetwork/articles/javase/index-140168.html. It comes bundled with Java SE 6.

Have a look at the tutorial. It's easy to register a schema file with your Unmarshaler/Marshaler and validate.

Answer 2

You can use DOM or SAX parsers for these operation.

EDIT Here some example with sax parsing

    SAXParserFactory factory = SAXParserFactory.newInstance();
    factory.setValidating(true);
    factory.setNamespaceAware(true);

    SAXParser parser = factory.newSAXParser();
    parser.setProperty("http://java.sun.com/xml/jaxp/properties/schemaLanguage", 
          "http://www.w3.org/2001/XMLSchema");

    XMLReader reader = parser.getXMLReader();

    reader.setErrorHandler(new ErrorHandler(){
          public void warning(SAXParseException e) throws SAXException {
                System.out.println(e.getMessage());
            }

            public void error(SAXParseException e) throws SAXException {
                System.out.println(e.getMessage());
            }

            public void fatalError(SAXParseException e) throws SAXException {
                System.out.println(e.getMessage());
            }

    });
    reader.parse(new InputSource("document.xml"));

(I'd took source from here)

Answer 3

Part 1 - Validate XML

You can use the javax.xml.validation APIs for this.

SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI); 
URL schemaURL = // The URL to your XML Schema; 
Schema schema = sf.newSchema(schemaURL); 
Validator validator = schema.newValidator();
validator.validate(xml);

Part 2 - OXM

Regarding the second part of your question, the best API for parsing XML into the domain object is JAXB. JAXB is a specification with multiple implementations. I lead the MOXy JAXB implementation that contains useful extensions such as XPath based mapping.

You could always do the validation during the conversion of XML to objects:

JAXBContext jc = JAXBContext.newInstance(Customer.class);
Umarshaller unmarshaller = jc.createUnmarshaller();

SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI); 
URL schemaURL = // The URL to your XML Schema; 
Schema schema = sf.newSchema(schemaURL); 
unmarshaller.setSchema(schema);

Customer customer = (Customer) unmarshaller.unmarshal(xml);

Answer 4

You can use Castor, that generate Java classes for your XSD. So you can convert your XML to objects and vice versa in few lines of code.

http://www.castor.org/1.3/index.html