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 byJAXBIntrospector.isElement(java.lang.Object)
; otherwise, a Marshaller.marshal method must throw aMarshalException
. 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 aJAXBElement
, 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 @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
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,
DefaultValidationEventHandler
is no longer used.
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:
marshal(Object,ContentHandler)
- the Marshaller won't invokeContentHandler.startDocument()
andContentHandler.endDocument()
.marshal(Object,Node)
- the property has no effect on this API.marshal(Object,OutputStream)
- the Marshaller won't generate an xml declaration.marshal(Object,Writer)
- the Marshaller won't generate an xml declaration.marshal(Object,Result)
- depends on the kind of Result object, see semantics for Node, ContentHandler, and Stream APIsmarshal(Object,XMLEventWriter)
- the Marshaller will not generateXMLStreamConstants.START_DOCUMENT
andXMLStreamConstants.END_DOCUMENT
events.marshal(Object,XMLStreamWriter)
- the Marshaller will not generateXMLStreamConstants.START_DOCUMENT
andXMLStreamConstants.END_DOCUMENT
events.
"TheMarshaller
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:
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.// 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 external listener callback mechanism enables the registration of a
Marshaller.Listener
instance with asetListener(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
Marshaller.Listener.beforeMarshal(Object)
andMarshaller.Listener.afterMarshal(Object)
.An event callback method throwing an exception terminates the current marshal process.
JAXBContext
,
Validator
,
Unmarshaller
Modifier and Type | Interface and Description |
---|---|
static class |
Marshaller.Listener
Register an instance of an implementation of this class with a
Marshaller to externally listen
for marshal events. |
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
JAXB_ENCODING
The name of the property used to specify the output encoding in
the marshalled XML data.
|
static java.lang.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.
|
static java.lang.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).
|
static java.lang.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.
|
static java.lang.String |
JAXB_SCHEMA_LOCATION
The name of the property used to specify the xsi:schemaLocation
attribute value to place in the marshalled XML output.
|
Modifier and Type | Method and Description |
---|---|
<A extends XmlAdapter> |
getAdapter(java.lang.Class<A> type)
Gets the adapter associated with the specified type.
|
AttachmentMarshaller |
getAttachmentMarshaller() |
ValidationEventHandler |
getEventHandler()
Return the current event handler or the default event handler if one
hasn't been set.
|
Marshaller.Listener |
getListener()
Return
Marshaller.Listener registered with this Marshaller . |
org.w3c.dom.Node |
getNode(java.lang.Object contentTree)
Get a DOM tree view of the content tree(Optional).
|
java.lang.Object |
getProperty(java.lang.String name)
Get the particular property in the underlying implementation of
Marshaller.
|
javax.xml.validation.Schema |
getSchema()
Get the JAXP 1.3
Schema object
being used to perform marshal-time validation. |
void |
marshal(java.lang.Object jaxbElement,
org.xml.sax.ContentHandler handler)
Marshal the content tree rooted at jaxbElement into SAX2 events.
|
void |
marshal(java.lang.Object jaxbElement,
java.io.File output)
Marshal the content tree rooted at jaxbElement into a file.
|
void |
marshal(java.lang.Object jaxbElement,
org.w3c.dom.Node node)
Marshal the content tree rooted at jaxbElement into a DOM tree.
|
void |
marshal(java.lang.Object jaxbElement,
java.io.OutputStream os)
Marshal the content tree rooted at jaxbElement into an output stream.
|
void |
marshal(java.lang.Object jaxbElement,
javax.xml.transform.Result result)
Marshal the content tree rooted at jaxbElement into the specified
javax.xml.transform.Result.
|
void |
marshal(java.lang.Object jaxbElement,
java.io.Writer writer)
Marshal the content tree rooted at jaxbElement into a Writer.
|
void |
marshal(java.lang.Object jaxbElement,
javax.xml.stream.XMLEventWriter writer)
Marshal the content tree rooted at jaxbElement into a
XMLEventWriter . |
void |
marshal(java.lang.Object jaxbElement,
javax.xml.stream.XMLStreamWriter writer)
Marshal the content tree rooted at jaxbElement into a
XMLStreamWriter . |
<A extends XmlAdapter> |
setAdapter(java.lang.Class<A> type,
A adapter)
Associates a configured instance of
XmlAdapter with this marshaller. |
void |
setAdapter(XmlAdapter adapter)
Associates a configured instance of
XmlAdapter with this marshaller. |
void |
setAttachmentMarshaller(AttachmentMarshaller am)
Associate a context that enables binary data within an XML document
to be transmitted as XML-binary optimized attachment.
|
void |
setEventHandler(ValidationEventHandler handler)
Allow an application to register a validation event handler.
|
void |
setListener(Marshaller.Listener listener)
Register marshal event callback
Marshaller.Listener with this Marshaller . |
void |
setProperty(java.lang.String name,
java.lang.Object value)
Set the particular property in the underlying implementation of
Marshaller.
|
void |
setSchema(javax.xml.validation.Schema schema)
Specify the JAXP 1.3
Schema
object that should be used to validate subsequent marshal operations
against. |
static final java.lang.String JAXB_ENCODING
static final java.lang.String JAXB_FORMATTED_OUTPUT
static final java.lang.String JAXB_SCHEMA_LOCATION
static final java.lang.String JAXB_NO_NAMESPACE_SCHEMA_LOCATION
static final java.lang.String JAXB_FRAGMENT
void marshal(java.lang.Object jaxbElement, javax.xml.transform.Result result) throws JAXBException
All JAXB Providers must at least support
DOMResult
,
SAXResult
, and
StreamResult
. It can
support other derived classes of Result as well.
jaxbElement
- The root of content tree to be marshalled.result
- XML will be sent to this ResultJAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, java.io.OutputStream os) throws JAXBException
jaxbElement
- The root of content tree to be marshalled.os
- XML will be added to this stream.JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, java.io.File output) throws JAXBException
jaxbElement
- The root of content tree to be marshalled.output
- File to be written. If this file already exists, it will be overwritten.JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, java.io.Writer writer) throws JAXBException
jaxbElement
- The root of content tree to be marshalled.writer
- XML will be sent to this writer.JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, org.xml.sax.ContentHandler handler) throws JAXBException
jaxbElement
- The root of content tree to be marshalled.handler
- XML will be sent to this handler as SAX2 events.JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, org.w3c.dom.Node node) throws JAXBException
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
(Document
,
DocumentFragment
, or
Element
)JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal jaxbElement (or any
object reachable from jaxbElement). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, javax.xml.stream.XMLStreamWriter writer) throws JAXBException
XMLStreamWriter
.jaxbElement
- The content tree to be marshalled.writer
- XML will be sent to this writer.JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullvoid marshal(java.lang.Object jaxbElement, javax.xml.stream.XMLEventWriter writer) throws JAXBException
XMLEventWriter
.jaxbElement
- The content tree rooted at jaxbElement to be marshalled.writer
- XML will be sent to this writer.JAXBException
- If any unexpected problem occurs during the marshalling.MarshalException
- If the ValidationEventHandler
returns false from its handleEvent method or the
Marshaller is unable to marshal obj (or any
object reachable from obj). See
Marshalling a JAXB element.java.lang.IllegalArgumentException
- If any of the method parameters are nullorg.w3c.dom.Node getNode(java.lang.Object contentTree) throws JAXBException
marshal(Object, org.w3c.dom.Node)
to force
a deep copy of the content tree to a DOM representation.contentTree
- - JAXB Java representation of XML contentjava.lang.UnsupportedOperationException
- If the JAXB provider implementation does not support a
DOM view of the content treejava.lang.IllegalArgumentException
- If any of the method parameters are nullJAXBException
- If any unexpected problem occursvoid setProperty(java.lang.String name, java.lang.Object value) throws PropertyException
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 setPropertyException
- when there is an error processing the given
property or valuejava.lang.IllegalArgumentException
- If the name parameter is nulljava.lang.Object getProperty(java.lang.String name) throws PropertyException
name
- the name of the property to retrievePropertyException
- when there is an error retrieving the given property or value
property namejava.lang.IllegalArgumentException
- If the name parameter is nullvoid setEventHandler(ValidationEventHandler handler) throws JAXBException
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.
handler
- the validation event handlerJAXBException
- if an error was encountered while setting the
event handlerValidationEventHandler getEventHandler() throws JAXBException
JAXBException
- if an error was encountered while getting the
current event handlervoid setAdapter(XmlAdapter adapter)
XmlAdapter
with this marshaller.
This is a convenience method that invokes setAdapter(adapter.getClass(),adapter);
.
java.lang.IllegalArgumentException
- if the adapter parameter is null.java.lang.UnsupportedOperationException
- if invoked agains a JAXB 1.0 implementation.setAdapter(Class,XmlAdapter)
<A extends XmlAdapter> void setAdapter(java.lang.Class<A> type, A adapter)
XmlAdapter
with this marshaller.
Every marshaller internally maintains a
Map
<Class
,XmlAdapter
>,
which it uses for marshalling classes whose fields/methods are annotated
with XmlJavaTypeAdapter
.
This method allows applications to use a configured instance of XmlAdapter
.
When an instance of an adapter is not given, a marshaller will create
one by invoking its default constructor.
type
- The type of the adapter. The specified instance will be used when
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.java.lang.IllegalArgumentException
- if the type parameter is null.java.lang.UnsupportedOperationException
- if invoked agains a JAXB 1.0 implementation.<A extends XmlAdapter> A getAdapter(java.lang.Class<A> type)
setAdapter(javax.xml.bind.annotation.adapters.XmlAdapter)
method.java.lang.IllegalArgumentException
- if the type parameter is null.java.lang.UnsupportedOperationException
- if invoked agains a JAXB 1.0 implementation.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.
java.lang.IllegalStateException
- if attempt to concurrently call this
method during a marshal operation.AttachmentMarshaller getAttachmentMarshaller()
void setSchema(javax.xml.validation.Schema 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.
schema
- Schema object to validate marshal operations against or null to disable validationjava.lang.UnsupportedOperationException
- could be thrown if this method is
invoked on an Marshaller created from a JAXBContext referencing
JAXB 1.0 mapped classesjavax.xml.validation.Schema getSchema()
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.java.lang.UnsupportedOperationException
- could be thrown if this method is
invoked on an Marshaller created from a JAXBContext referencing
JAXB 1.0 mapped classesvoid setListener(Marshaller.Listener listener)
Register marshal event callback Marshaller.Listener
with this 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.
listener
- an instance of a class that implements Marshaller.Listener
Marshaller.Listener getListener()
Return Marshaller.Listener
registered with this Marshaller
.
Marshaller.Listener
or null
if no Listener is registered with this Marshaller.