Feeds

A practical guide to JAXB 2.0

Take a peek at its new features

  • alert
  • submit to reddit

Beginner's guide to SSL certificates

Unmarshalling an XML Document

In this section we shall unmarshal the example XML document, catalog.xml. In the JAXBUnMarshaller.java class create a JAXBContext object, which provides a JAXB context for implementing JAXB binding framework operations. A JAXBContext object is initialised with a colon-separated list of Java package names, which consist of schema-derived classes and user annotated classes.

JAXBContext jaxbContext = JAXBContext.newInstance("generated");

Create an Unmarshaller object, which is used to convert an XML document to a Java object.

Unmarshaller unMarshaller = jaxbContext.createUnmarshaller();

If the application were a JAXB 1.0 application, we would have set the Unmarshaller to be validating using setValidating()method. The setValidating() method has been deprecated in JAXB 2.0. Schema validation in JAXB 2.0 is performed using JAXP 1.3 validation API. Create a SchemaFactory object and create a Schema object from the SchemaFactory object. Set the schema on the Unmarshaller object. Error handling in JAXB 2.0 is implemented using the ValidationEventHandler interface. To add error handling to the example application, create a class CustomValidationEventHandler that implements the ValidatonEventHandler interface. Create a ValidationEventHandler object and set the ValidationEventHandler object on the Unmarshaller object.

Unmarshal using the unmarshal() method, which returns a parameterized JAXBElement object. The parameter type is CatalogType in the example application.

JAXBElement<CatalogType> catalogElement =(JAXBElement<CatalogType>) unMarshaller.unmarshal(xmlDocument); 

Obtain a CatalogType object from the JAXBElement object.

CatalogType catalog=catalogElement.getValue();

Retrieve the journalTitle and publisher values. Obtain a parameterized list of parameter type JournalType. Iterate over the List object and obtain a parameterized list of parameter type ArticleType for each of the JournalType objects. Iterate over the parameterized list of parameter type ArticleType and output values for edition, title and author.

To run the JAXBUnMarshaller.java application in the Eclipse project JAXB2, right-click on the JAXBUnMarshaller.java application and select Run As>Run. Output generated by running the application in Eclipse is shown in Figure 7.

Output from Unmarshalling

Marshalling an XML Document

In this section we shall marshal an XML document, catalog.xml. In the JAXBMarshaller.java class create a JAXBContext object with the procedure similar to the previous section. Create a Marshaller object, which is used to marshal a Java object to an XML document.

Marshaller marshaller = jaxbContext.createMarshaller();

To produce formatted output, set the Marshaller property jaxb.formatted.output to true.

marshaller.setProperty("jaxb.formatted.output",new Boolean(true)); 

Next, create a Java object representation of the XML document to be marshalled. Create an ObjectFactory object, which is used to initialise the Java object

ObjectFactory factory = new ObjectFactory();

Create a CatalogType object, which represents root element catalog.

CatalogType catalog = factory.createCatalogType();

Set the journalTitle and publisher attributes of root element catalog. Create a JournalType object, which represents a journal element. Get a list of parameter type JournalType from the CatalogType object and add the JournalType object to the List object.

JournalType journal = factory.createJournalType();
List<JournalType> journalList = catalog.getJournal();
journalList.add(journal); 

Choosing a cloud hosting partner with confidence

More from The Register

next story
That dreaded syncing feeling: Will Microsoft EVER fix OneDrive?
Microsoft's long history of broken Windows sync
Mozilla, EFF, Cisco back free-as-in-FREE-BEER SSL cert authority
Let’s Encrypt to give HTTPS-everywhere a boost in 2015
SLURP! Flick your TONGUE around our LOLLIPOP – Google
Android 5 is coming – IF you're lucky enough to have the right gadget
Nokia's N1 fondleslab's HIDDEN BRILLIANCE: The 'Z Launcher'
Sugarcoating Android's Lollipop makes tab easier to swallow
Bug fixes! Get your APPLE BUG FIXES! iOS and OS X updates right here!
Yosemite fixes Wi-Fi hiccup, older iOS devices get performance boost
Microsoft: Your Linux Docker containers are now OURS to command
New tool lets admins wrangle Linux apps from Windows
Facebook, working on Facebook at Work, works on Facebook. At Work
You don't want your cat or drunk pics at the office
Soz, web devs: Google snatches its Wallet off the table
Killing off web service in 3 months... but app-happy bonkers are fine
Meet Windows 10's new UI for OneDrive – also known as File Explorer
New preview build continues Redmond's retreat to the desktop
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.
New hybrid storage solutions
Tackling data challenges through emerging hybrid storage solutions that enable optimum database performance whilst managing costs and increasingly large data stores.