Feeds

A practical guide to JAXB 2.0

Take a peek at its new features

  • alert
  • submit to reddit

Remote control for virtualized desktops

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); 

Internet Security Threat Report 2014

More from The Register

next story
Be real, Apple: In-app goodie grab games AREN'T FREE – EU
Cupertino stands down after Euro legal threats
Download alert: Nearly ALL top 100 Android, iOS paid apps hacked
Attack of the Clones? Yeah, but much, much scarier – report
You stupid BRICK! PCs running Avast AV can't handle Windows fixes
Fix issued, fingers pointed, forums in flames
Microsoft: Your Linux Docker containers are now OURS to command
New tool lets admins wrangle Linux apps from Windows
Bada-Bing! Mozilla flips Firefox to YAHOO! for search
Microsoft system will be the default for browser in US until 2020
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
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
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.
5 critical considerations for enterprise cloud backup
Key considerations when evaluating cloud backup solutions to ensure adequate protection security and availability of enterprise data.
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.
Choosing a cloud hosting partner with confidence
Download Choosing a Cloud Hosting Provider with Confidence to learn more about cloud computing - the new opportunities and new security challenges.