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Difference between revisions of "EclipseLink/UserGuide/MOXy/Runtime/Bootstrapping"

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<?xml version="1.0" encoding="US-ASCII"?>
 
<?xml version="1.0" encoding="US-ASCII"?>
 
<sessions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="file://xsd/eclipselink_sessions_1.0.xsd" version="0">
 
<sessions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="file://xsd/eclipselink_sessions_1.0.xsd" version="0">
<session xsi:type="database-session">
+
    <session xsi:type="database-session">
<name>example.moxy.project</name>
+
        <name>example.moxy.project</name>
<primary-project xsi:type="class">example.mappings.EclipseLinkProject</primary-project>
+
        <primary-project xsi:type="class">example.mappings.EclipseLinkProject</primary-project>
</session>
+
    </session>
 
</sessions>
 
</sessions>
  

Revision as of 14:16, 10 June 2011

EclipseLink MOXy

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Elug api package icon.png Key API

Bootstrapping

EclipseLink MOXy offers several options when creating your JAXBContext. You have the option of bootstrapping from:

  • A list of one or more JAXB-annotated Classes
  • A list of one or more EclipseLink OXM Bindings Files defining the mappings for your Java classes
  • A combination of classes and OXM files
  • A list of context paths
  • A list of Session names, referring to EclipseLink Sessions defined in sessions.xml


JAXBContext API

The following methods on JAXBContext are used to create new instances of JAXBContexts:

public static JAXBContext newInstance(Class... classesToBeBound) throws JAXBException
 
public static JAXBContext newInstance(Class[] classesToBeBound, Map<String,?> properties) throws JAXBException
 
public static JAXBContext newInstance(String contextPath) throws JAXBException
 
public static JAXBContext newInstance(String contextPath, ClassLoader classLoader) throws JAXBException
 
public static JAXBContext newInstance(String contextPath, ClassLoader classLoader, Map<String,?> properties) throws JAXBException
  • classesToBeBound - List of Java classes to be recognized by the new JAXBContext.
  • contextPath - List of Java package names that contain mapped classes.
  • classLoader - The class loader used to locate the mapped classes.
  • properties - A map of additional properties.


Bootstrapping from Classes

If you already have a collection of Java Classes annotated with JAXB annotations, you can provide a list of these Classes directly:

JAXBContext context = JAXBContext.newInstance(Company.class, Employee.class);


Bootstrapping from a Context Path

Another way to bootstrap your JAXBContext is with a String, called the "context path". This is a colon-delimited list of package names containing your mapped classes. Using this approach, there are a few different ways that EclipseLink will discover your model classes:

jaxb.index

The context path could contain a file named jaxb.index, which is a simple text file containing the class names from the current package that will be brought into the JAXBContext:

src/example/jaxb.index:

Employee
PhoneNumber

ObjectFactory

The context path could also contain a class called ObjectFactory, which is a special factory class that JAXB will look for. This class contains create() methods for each of the types in your model. Typically the ObjectFactory will be generated by the JAXB XSD-to-Java Compiler (xjc), but one can be written by hand as well.

src/example/ObjectFactory.java:

@XmlRegistry
public class ObjectFactory {
 
    private final static QName _Employee_QNAME = new QName("", "employee");
    private final static QName _PhoneNumber_QNAME = new QName("", "phone-number");
 
    public ObjectFactory() {
    }
 
    public EmployeeType createEmployeeType() {
        return new EmployeeType();
    }
 
    @XmlElementDecl(namespace = "", name = "employee")
    public JAXBElement<EmployeeType> createEmployee(EmployeeType value) {
        return new JAXBElement<EmployeeType>(_Employee_QNAME, EmployeeType.class, null, value);
    }
 
    public PhoneNumberType createPhoneNumberType() {
        return new PhoneNumberType();
    }
 
    @XmlElementDecl(namespace = "", name = "phone-number")
    public JAXBElement<PhoneNumberType> createPhoneNumber(PhoneNumberType value) {
        return new JAXBElement<PhoneNumberType>(_PhoneNumber_QNAME, PhoneNumberType.class, null, value);
    }
 
}

sessions.xml

EclipseLink MOXy also allows you to specify your mapping information in EclipseLink's legacy session.xml file. In this case, the context path will be a colon-delimited list of EclipseLink Session names.

sessions.xml

<?xml version="1.0" encoding="US-ASCII"?>
<sessions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="file://xsd/eclipselink_sessions_1.0.xsd" version="0">
    <session xsi:type="database-session">
        <name>example.moxy.project</name>
        <primary-project xsi:type="class">example.mappings.EclipseLinkProject</primary-project>
    </session>
</sessions>

Bootstrapping from EclipseLink OXM

If you would like to have more control over how your classes will be mapped to XML, you can instead bootstrap from an EclipseLink OXM bindings file. Using this approach, you can take advantage of EclipseLink's robust mappings framework and customize how each complex type in XML maps to its Java counterpart.

Links to the actual OXM files are passed in via the properties parameter, using a special key, JAXBContextFactory.ECLIPSELINK_OXM_XML_KEY. The value of this key will be a handle to the OXM metadata file, in the form of one of the following:

  • java.io.File
  • java.io.InputStream
  • java.io.Reader
  • java.net.URL
  • javax.xml.stream.XMLEventReader
  • javax.xml.stream.XMLStreamReader
  • javax.xml.transform.Source
  • org.w3c.dom.Node
  • org.xml.sax.InputSource


When bootstrapping from OXM, the package specified by contextPath must contain a jaxb.properties file that specifies the EclipseLink JAXBContextFactory.

InputStream iStream = myClassLoader.getResourceAsStream("example/eclipselink-oxm.xml");
 
Map<String, Object> properties = new HashMap<String, Object>();
properties.put(JAXBContextFactory.ECLIPSELINK_OXM_XML_KEY, iStream);
 
JAXBContext context = JAXBContext.newInstance("example", myClassLoader, properties);