javax.xml.bind
Interface Marshaller

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 in all following code fragments:

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

Marshalling to a File:

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

Marshalling to a SAX ContentHandler:

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

Marshalling to a DOM Node:

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

       m.marshal( obj, doc );

Marshalling to a java.io.OutputStream:

       m.marshal( obj, System.out );

Marshalling to a java.io.Writer:

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

Marshalling to a javax.xml.transform.SAXResult:

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

       m.marshal( obj, result );

Marshalling to a javax.xml.transform.DOMResult:

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

Marshalling to a javax.xml.transform.StreamResult:

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

Marshalling java.lang.Object Objects

Although each of the marshal methods accepts a java.lang.Object as its first parameter, JAXB Providers are not required to be able to marshal any arbitrary java.lang.Object. If the JAXBContext object that was used to create this Marshaller does not have enough information to know how to marshal the object parameter (or any objects reachable from it), then the marshal operation will throw a MarshalException. Even though JAXB Providers are not required to be able to marshal arbitrary java.lang.Object objects, some providers may allow it.

Encoding

By default, the Marshaller will use UTF-8 encoding when generating XML data to a java.io.File, java.io.OutputStream, and java.io.Writer. Use the setProperty API to change the ouput encoding used during these marshal operations.

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.

Although there is no way to enable validation during the marshal operation, it is possible that certain types of validation events will be detected during the operation. These 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 the default event handler which will terminate the marshal operation after encountering the first error or fatal error.

Supported Properties

jaxb.encoding

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

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

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

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.

Encoding Parameter Name

JAXB Providers must convert the encoding parameter to its canonical form as defined by the IANA Charset Registry. Some character sets have a historical name that is defined for compatibility with previous versions of the Java platform. These historical names must not be used since they may violate the W3C XML v1.0 Recommendation requirements for valid encoding names. In some cases, the historical name is the same as the canonical name, but not always. The client application should be allowed to specify the encoding using any of the available aliases for that charset (For example, "UTF8" and "UTF-8" should both resolve to the canonical name for this encoding which is "UTF-8". However, the historical name is "UTF8", which should not be used by providers).

Please refer to the javadocs for java.nio.charset.Charset for more details.

Since:

JAXB1.0

See Also:

JAXBContext, Validator, Unmarshaller

Field Summary

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 formated with linefeeds and indentation.
static java.lang.String	JAXB_NONAMESPACESCHEMALOCATION The name of the property used to specify the the xsi:noNamespaceSchemaLocation attribute value to place in the marshalled XML output.
static java.lang.String	JAXB_SCHEMALOCATION The name of the property used to specify the xsi:schemaLocation attribute value to place in the marshalled XML output.

Method Summary

ValidationEventHandler	getEventHandler() Return the current event handler or the default event handler if one hasn't been set.
java.lang.Object	getProperty(java.lang.String name) Get the particular property in the underlying implementation of Marshaller.
void	marshal(java.lang.Object obj, ContentHandler handler) Marshal the content tree rooted at obj into SAX2 events.
void	marshal(java.lang.Object obj, Node node) Marshal the content tree rooted at obj into a DOM tree.
void	marshal(java.lang.Object obj, java.io.OutputStream os) Marshal the content tree rooted at obj into an output stream.
void	marshal(java.lang.Object obj, Result result) Marshal the content tree rooted at obj into the specified javax.xml.transform.Result.
void	marshal(java.lang.Object obj, java.io.Writer writer) Marshal the content tree rooted at obj into a Writer.
void	setEventHandler(ValidationEventHandler handler) Allow an application to register a validation event handler.
void	setProperty(java.lang.String name, java.lang.Object value) Set the particular property in the underlying implementation of Marshaller.

Field Detail

JAXB_ENCODING

public static final java.lang.String JAXB_ENCODING

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

See Also:

Constant Field Values

JAXB_FORMATTED_OUTPUT

public static final java.lang.String JAXB_FORMATTED_OUTPUT

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

See Also:

Constant Field Values

JAXB_SCHEMALOCATION

public static final java.lang.String JAXB_SCHEMALOCATION

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

See Also:

Constant Field Values

JAXB_NONAMESPACESCHEMALOCATION

public static final java.lang.String JAXB_NONAMESPACESCHEMALOCATION

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

See Also:

Constant Field Values

Method Detail

marshal

public void marshal(java.lang.Object obj,
Result result)
             throws JAXBException

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

All JAXB Providers must at least support DOMResult, SAXResult, and StreamResult. It can support other derived classes of Result as well.

Parameters:

obj - The content tree to be marshalled.

result - XML will be sent to this Result

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

MarshalException - If obj (or any object reachable from obj) can not be marshalled. See Marshalling objects.

marshal

public void marshal(java.lang.Object obj,
                    java.io.OutputStream os)
             throws JAXBException

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

Parameters:

obj - The content tree to be marshalled.

os - XML will be added to this stream.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

MarshalException - If obj (or any object reachable from obj) can not be marshalled. See Marshalling objects.

marshal

public void marshal(java.lang.Object obj,
                    java.io.Writer writer)
             throws JAXBException

Marshal the content tree rooted at obj into a Writer.

Parameters:

obj - The content tree to be marshalled.

writer - XML will be sent to this writer.

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

MarshalException - If obj (or any object reachable from obj) can not be marshalled. See Marshalling objects.

marshal

public void marshal(java.lang.Object obj,
ContentHandler handler)
             throws JAXBException

Marshal the content tree rooted at obj into SAX2 events.

Parameters:

obj - The 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.

MarshalException - If obj (or any object reachable from obj) can not be marshalled. See Marshalling objects.

marshal

public void marshal(java.lang.Object obj,
Node node)
             throws JAXBException

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

Parameters:

obj - 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)

Throws:

JAXBException - If any unexpected problem occurs during the marshalling.

MarshalException - If obj (or any object reachable from obj) can not be marshalled. See Marshalling objects.

setProperty

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

Set the particular property in the underlying implementation of Marshaller. 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

getProperty

public java.lang.Object getProperty(java.lang.String name)
                             throws PropertyException

Get the particular property in the underlying implementation of Marshaller. 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

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.

Parameters:

handler - the validation event handler

Throws:

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

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