javax.xml.bind
interface Marshaller

All Known Implementing Classes:

AbstractMarshallerImpl

Most common way to construct:

JAXBContext jc = …;

Marshaller marshaller = jc.createMarshaller();

Based on 318 examples

public interface Marshaller

The Marshaller class is responsible for governing the process of serializing Java content trees back into XML data. It provides the basic marshalling methods:

Assume the following setup code for all following code fragments:

       JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );
       Unmarshaller u = jc.createUnmarshaller();
       Object element = u.unmarshal( new File( "foo.xml" ) );
       Marshaller m = jc.createMarshaller();
    

Marshalling to a File:

       OutputStream os = new FileOutputStream( "nosferatu.xml" );
       m.marshal( element, os );
    

Marshalling to a SAX ContentHandler:

       // assume MyContentHandler instanceof ContentHandler
       m.marshal( element, new MyContentHandler() );  
    

Marshalling to a DOM Node:

       DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
       dbf.setNamespaceAware(true);
       DocumentBuilder db = dbf.newDocumentBuilder();
       Document doc = db.newDocument();

       m.marshal( element, doc );
    

Marshalling to a java.io.OutputStream:

       m.marshal( element, System.out );
    

Marshalling to a java.io.Writer:

       m.marshal( element, new PrintWriter( System.out ) );
    

Marshalling to a javax.xml.transform.SAXResult:

       // assume MyContentHandler instanceof ContentHandler
       SAXResult result = new SAXResult( new MyContentHandler() );

       m.marshal( element, result );
    

Marshalling to a javax.xml.transform.DOMResult:

       DOMResult result = new DOMResult();
       
       m.marshal( element, result );
    

Marshalling to a javax.xml.transform.StreamResult:

       StreamResult result = new StreamResult( System.out );
 
       m.marshal( element, result );
    

Marshalling to a javax.xml.stream.XMLStreamWriter:

       XMLStreamWriter xmlStreamWriter = 
           XMLOutputFactory.newInstance().createXMLStreamWriter( ... );
 
       m.marshal( element, xmlStreamWriter );
    

Marshalling to a javax.xml.stream.XMLEventWriter:

       XMLEventWriter xmlEventWriter = 
           XMLOutputFactory.newInstance().createXMLEventWriter( ... );
 
       m.marshal( element, xmlEventWriter );
    

Marshalling content tree rooted by a JAXB element

The first parameter of the overloaded Marshaller.marshal(java.lang.Object, ...) methods must be a JAXB element as computed by {@link JAXBIntrospector#isElement(java.lang.Object)}; otherwise, a Marshaller.marshal method must throw a {@link MarshalException}. There exist two mechanisms to enable marshalling an instance that is not a JAXB element. One method is to wrap the instance as a value of a {@link JAXBElement}, and pass the wrapper element as the first parameter to a Marshaller.marshal method. For java to schema binding, it is also possible to simply annotate the instance's class with @{@link XmlRootElement}.

Encoding

By default, the Marshaller will use UTF-8 encoding when generating XML data to a java.io.OutputStream, or a java.io.Writer. Use the {@link #setProperty(String,Object) setProperty} API to change the output encoding used during these marshal operations. Client applications are expected to supply a valid character encoding name as defined in the W3C XML 1.0 Recommendation and supported by your Java Platform.

Validation and Well-Formedness

Client applications are not required to validate the Java content tree prior to calling any of the marshal API's. Furthermore, there is no requirement that the Java content tree be valid with respect to its original schema in order to marshal it back into XML data. Different JAXB Providers will support marshalling invalid Java content trees at varying levels, however all JAXB Providers must be able to marshal a valid content tree back to XML data. A JAXB Provider must throw a MarshalException when it is unable to complete the marshal operation due to invalid content. Some JAXB Providers will fully allow marshalling invalid content, others will fail on the first validation error.

Even when schema validation is not explictly enabled for the marshal operation, it is possible that certain types of validation events will be detected during the operation. Validation events will be reported to the registered event handler. If the client application has not registered an event handler prior to invoking one of the marshal API's, then events will be delivered to a default event handler which will terminate the marshal operation after encountering the first error or fatal error. Note that for JAXB 2.0 and later versions, {@link javax.xml.bind.helpers.DefaultValidationEventHandler} is no longer used.

Supported Properties

All JAXB Providers are required to support the following set of properties. Some providers may support additional properties.

jaxb.encoding - value must be a java.lang.String

The output encoding to use when marshalling the XML data. The Marshaller will use "UTF-8" by default if this property is not specified.

jaxb.formatted.output - value must be a java.lang.Boolean

This property controls whether or not the Marshaller will format the resulting XML data with line breaks and indentation. A true value for this property indicates human readable indented xml data, while a false value indicates unformatted xml data. The Marshaller will default to false (unformatted) if this property is not specified.

jaxb.schemaLocation - value must be a java.lang.String

This property allows the client application to specify an xsi:schemaLocation attribute in the generated XML data. The format of the schemaLocation attribute value is discussed in an easy to understand, non-normative form in Section 5.6 of the W3C XML Schema Part 0: Primer and specified in Section 2.6 of the W3C XML Schema Part 1: Structures.

jaxb.noNamespaceSchemaLocation - value must be a java.lang.String

This property allows the client application to specify an xsi:noNamespaceSchemaLocation attribute in the generated XML data. The format of the schemaLocation attribute value is discussed in an easy to understand, non-normative form in Section 5.6 of the W3C XML Schema Part 0: Primer and specified in Section 2.6 of the W3C XML Schema Part 1: Structures.

jaxb.fragment - value must be a java.lang.Boolean

This property determines whether or not document level events will be generated by the Marshaller. If the property is not specified, the default is false. This property has different implications depending on which marshal api you are using - when this property is set to true:

• {@link #marshal(Object,org.xml.sax.ContentHandler) marshal(Object,ContentHandler)} - the Marshaller won't invoke {@link org.xml.sax.ContentHandler#startDocument()} and {@link org.xml.sax.ContentHandler#endDocument()}.
• {@link #marshal(Object,org.w3c.dom.Node) marshal(Object,Node)} - the property has no effect on this API.
• {@link #marshal(Object,java.io.OutputStream) marshal(Object,OutputStream)} - the Marshaller won't generate an xml declaration.
• {@link #marshal(Object,java.io.Writer) marshal(Object,Writer)} - the Marshaller won't generate an xml declaration.
• {@link #marshal(Object,javax.xml.transform.Result) marshal(Object,Result)} - depends on the kind of Result object, see semantics for Node, ContentHandler, and Stream APIs
• {@link #marshal(Object,javax.xml.stream.XMLEventWriter) marshal(Object,XMLEventWriter)} - the Marshaller will not generate {@link javax.xml.stream.events.XMLEvent#START_DOCUMENT} and {@link javax.xml.stream.events.XMLEvent#END_DOCUMENT} events.
• {@link #marshal(Object,javax.xml.stream.XMLStreamWriter) marshal(Object,XMLStreamWriter)} - the Marshaller will not generate {@link javax.xml.stream.events.XMLEvent#START_DOCUMENT} and {@link javax.xml.stream.events.XMLEvent#END_DOCUMENT} events.

Marshal Event Callbacks

"The {@link Marshaller} provides two styles of callback mechanisms that allow application specific processing during key points in the unmarshalling process. In 'class defined' event callbacks, application specific code placed in JAXB mapped classes is triggered during marshalling. 'External listeners' allow for centralized processing of marshal events in one callback method rather than by type event callbacks.

Class defined event callback methods allow any JAXB mapped class to specify its own specific callback methods by defining methods with the following method signatures:

   // Invoked by Marshaller after it has created an instance of this object.
   boolean beforeMarshal(Marshaller);
 
   // Invoked by Marshaller after it has marshalled all properties of this object.
   void afterMmarshal(Marshaller);
 

The class defined event callback methods should be used when the callback method requires access to non-public methods and/or fields of the class.

The external listener callback mechanism enables the registration of a {@link Listener} instance with a {@link Marshaller#setListener(Listener)}. The external listener receives all callback events, allowing for more centralized processing than per class defined callback methods.

The 'class defined' and external listener event callback methods are independent of each other, both can be called for one event. The invocation ordering when both listener callback methods exist is defined in {@link Listener#beforeMarshal(Object)} and {@link Listener#afterMarshal(Object)}.

An event callback method throwing an exception terminates the current marshal process.

JAXB_ENCODING

public static final String JAXB_ENCODING

The name of the property used to specify the output encoding in the marshalled XML data.

JAXB_FORMATTED_OUTPUT

public static final String JAXB_FORMATTED_OUTPUT

The name of the property used to specify whether or not the marshalled XML data is formatted with linefeeds and indentation.

JAXB_FRAGMENT

public static final String JAXB_FRAGMENT

The name of the property used to specify whether or not the marshaller will generate document level events (ie calling startDocument or endDocument).

JAXB_NO_NAMESPACE_SCHEMA_LOCATION

public static final String JAXB_NO_NAMESPACE_SCHEMA_LOCATION

The name of the property used to specify the xsi:noNamespaceSchemaLocation attribute value to place in the marshalled XML output.

JAXB_SCHEMA_LOCATION

public static final String JAXB_SCHEMA_LOCATION

The name of the property used to specify the xsi:schemaLocation attribute value to place in the marshalled XML output.

getAdapter

public XmlAdapter getAdapter(Class type)

Gets the adapter associated with the specified type. This is the reverse operation of the {@link #setAdapter} method.

Parameters:

type

getAttachmentMarshaller

public AttachmentMarshaller getAttachmentMarshaller()

getEventHandler

public ValidationEventHandler getEventHandler()
                                       throws JAXBException

Return the current event handler or the default event handler if one hasn't been set.

Returns:

the current ValidationEventHandler or the default event handler if it hasn't been set

Throws:

JAXBException - if an error was encountered while getting the current event handler

getListener

public Marshaller.Listener getListener()

Return {@link Listener} registered with this {@link Marshaller}.

Returns:

registered {@link Listener} or null if no Listener is registered with this Marshaller.

getNode

public Node getNode(Object contentTree)
             throws JAXBException

Get a DOM tree view of the content tree(Optional). If the returned DOM tree is updated, these changes are also visible in the content tree. Use {@link #marshal(Object, org.w3c.dom.Node)} to force a deep copy of the content tree to a DOM representation.

Parameters:

contentTree - - JAXB Java representation of XML content

Returns:

the DOM tree view of the contentTree

Throws:

JAXBException - If any unexpected problem occurs

getProperty

public Object getProperty(String name)
                   throws PropertyException

Get the particular property in the underlying implementation of Marshaller. This method can only be used to get one of the standard JAXB defined properties above or a provider specific property. Attempting to get an undefined property will result in a PropertyException being thrown. See Supported Properties.

Parameters:

name - the name of the property to retrieve

Returns:

the value of the requested property

Throws:

PropertyException - when there is an error retrieving the given property or value property name

getSchema

public Schema getSchema()

Get the JAXP 1.3 {@link javax.xml.validation.Schema Schema} object being used to perform marshal-time validation. If there is no Schema set on the marshaller, then this method will return null indicating that marshal-time validation will not be performed.

Returns:

the Schema object being used to perform marshal-time validation or null if not present.

marshal

public void marshal(Object jaxbElement,
                    ContentHandler handler)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into SAX2 events.

Parameters:

jaxbElement - The root of content tree to be marshalled.

handler - XML will be sent to this handler as SAX2 events.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    File output)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into a file.

Parameters:

jaxbElement - The root of content tree to be marshalled.

output - File to be written. If this file already exists, it will be overwritten.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    Node node)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into a DOM tree.

Parameters:

jaxbElement - The content tree to be marshalled.

node - DOM nodes will be added as children of this node. This parameter must be a Node that accepts children ({@link org.w3c.dom.Document}, {@link org.w3c.dom.DocumentFragment}, or {@link org.w3c.dom.Element})

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    OutputStream os)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into an output stream.

Parameters:

jaxbElement - The root of content tree to be marshalled.

os - XML will be added to this stream.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    Result result)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into the specified javax.xml.transform.Result.

All JAXB Providers must at least support {@link javax.xml.transform.dom.DOMResult}, {@link javax.xml.transform.sax.SAXResult}, and {@link javax.xml.transform.stream.StreamResult}. It can support other derived classes of Result as well.

Parameters:

jaxbElement - The root of content tree to be marshalled.

result - XML will be sent to this Result

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    Writer writer)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into a Writer.

Parameters:

jaxbElement - The root of content tree to be marshalled.

writer - XML will be sent to this writer.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    XMLEventWriter writer)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into a {@link javax.xml.stream.XMLEventWriter}.

Parameters:

jaxbElement - The content tree rooted at jaxbElement to be marshalled.

writer - XML will be sent to this writer.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

marshal

public void marshal(Object jaxbElement,
                    XMLStreamWriter writer)
             throws JAXBException

Marshal the content tree rooted at jaxbElement into a {@link javax.xml.stream.XMLStreamWriter}.

Parameters:

jaxbElement - The content tree to be marshalled.

writer - XML will be sent to this writer.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

setAdapter

public void setAdapter(Class type,
                       XmlAdapter adapter)

Associates a configured instance of {@link XmlAdapter} with this marshaller.

Every marshaller internally maintains a {@link java.util.Map}<{@link Class},{@link XmlAdapter}>, which it uses for marshalling classes whose fields/methods are annotated with {@link javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter}.

This method allows applications to use a configured instance of {@link XmlAdapter}. When an instance of an adapter is not given, a marshaller will create one by invoking its default constructor.

Parameters:

type - The type of the adapter. The specified instance will be used when {@link javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter#value()} refers to this type.

adapter - The instance of the adapter to be used. If null, it will un-register the current adapter set for this type.

setAdapter

public void setAdapter(XmlAdapter adapter)

Associates a configured instance of {@link XmlAdapter} with this marshaller.

This is a convenience method that invokes setAdapter(adapter.getClass(),adapter);.

Parameters:

adapter

setAttachmentMarshaller

public void setAttachmentMarshaller(AttachmentMarshaller am)

Associate a context that enables binary data within an XML document to be transmitted as XML-binary optimized attachment. The attachment is referenced from the XML document content model by content-id URIs(cid) references stored within the xml document.

Parameters:

am

setEventHandler

public void setEventHandler(ValidationEventHandler handler)
                     throws JAXBException

Allow an application to register a validation event handler.

The validation event handler will be called by the JAXB Provider if any validation errors are encountered during calls to any of the marshal API's. If the client application does not register a validation event handler before invoking one of the marshal methods, then validation events will be handled by the default event handler which will terminate the marshal operation after the first error or fatal error is encountered.

Calling this method with a null parameter will cause the Marshaller to revert back to the default default event handler.

Parameters:

handler - the validation event handler

Throws:

JAXBException - if an error was encountered while setting the event handler

setListener

public void setListener(Marshaller.Listener listener)

Register marshal event callback {@link Listener} with this {@link Marshaller}.

There is only one Listener per Marshaller. Setting a Listener replaces the previous set Listener. One can unregister current Listener by setting listener to null.

Parameters:

listener - an instance of a class that implements {@link Listener}

setProperty

public void setProperty(String name,
                        Object value)
                 throws PropertyException

Set the particular property in the underlying implementation of Marshaller. This method can only be used to set one of the standard JAXB defined properties above or a provider specific property. Attempting to set an undefined property will result in a PropertyException being thrown. See Supported Properties.

Parameters:

name - the name of the property to be set. This value can either be specified using one of the constant fields or a user supplied string.

value - the value of the property to be set

Throws:

PropertyException - when there is an error processing the given property or value

setSchema

public void setSchema(Schema schema)

Specify the JAXP 1.3 {@link javax.xml.validation.Schema Schema} object that should be used to validate subsequent marshal operations against. Passing null into this method will disable validation.

This method allows the caller to validate the marshalled XML as it's marshalled.

Initially this property is set to null.

Parameters:

schema - Schema object to validate marshal operations against or null to disable validation