javax.xml.bind

Interface Unmarshaller

Known Subinterfaces:
JMUnmarshaller
Known Implementing Classes:
AbstractUnmarshallerImpl, JMUnmarshallerImpl

public interface Unmarshaller

A Unmarshaller is the opposite of the Marshaller: It takes as input XML in either of several representations (byte or character stream, DOM node, or a series of SAX events) and returns a JAXB object with the same contents.

If the JAXB user demands, the Unmarshaller may also validate the content tree that it sees.

Author:
JSR-31
Since:
JAXB1.0
See Also:
JAXBContext, Marshaller, Validator

Method Summary

ValidationEventHandler
getEventHandler()
If the JAXB application has registered a custom handler for validation events, returns that handler.
java.lang.Object
getProperty(String pName)
Returnss the unmarshaller property pName to the value pValue.
UnmarshallerHandler
getUnmarshallerHandler()
Returns a SAX 2 org.xml.sax.ContentHandler, which is able to parse a SAX event stream and convert it into a JAXB object.
boolean
isValidating()
Sets whether the Unmarshaller is validating the objects that it reads.
void
setEventHandler(ValidationEventHandler pHandler)
An application may customize the Unmarshallers behaviour in case of validation problems by supplying a custom handler for validation events.
void
setProperty(String pName, Object pValue)
Sets the unmarshaller property pName to the value pValue.
void
setValidating(boolean pValidating)
Sets whether the Unmarshaller is validating the objects that it reads.
java.lang.Object
unmarshal(InputSource pSource)
The Unmarshaller reads the byte stream or character stream referred by the org.xml.sax.InputSource and converts it into an equivalent JAXB object.
java.lang.Object
unmarshal(Node pNode)
The Unmarshaller converts the given node into an equivalent JAXB object.
java.lang.Object
unmarshal(Source pSource)
The Unmarshaller reads the XML representation from the given Source and converts it into an equivalent JAXB object.
java.lang.Object
unmarshal(java.io.File pFile)
This method takes opens the given file pFile for input.
java.lang.Object
unmarshal(java.io.InputStream pStream)
The Unmarshaller reads the given byte stream and converts it into an equivalent JAXB object.
java.lang.Object
unmarshal(java.net.URL pURL)
This method takes connects to the given pURL and opens a byte stream for input.

Method Details

getEventHandler

public ValidationEventHandler getEventHandler()
            throws JAXBException
If the JAXB application has registered a custom handler for validation events, returns that handler. Otherwise returns the default handler, which is triggering an exception in case of errors and fatal errors.

getProperty

public java.lang.Object getProperty(String pName)
            throws PropertyException
Returnss the unmarshaller property pName to the value pValue. Note, that the value type depends on the property being set.
Parameters:
pName - The property name.
Throws:
PropertyException - An error occurred while processing the property.

getUnmarshallerHandler

public UnmarshallerHandler getUnmarshallerHandler()
            throws JAXBException
Returns a SAX 2 org.xml.sax.ContentHandler, which is able to parse a SAX event stream and convert it into a JAXB object. This is particularly useful in a stack of SAX handlers. (Think of Apache Cocoon.)

Note: The JAXB provider may choose to return the same handler again, if the method is invoked more than once. In other words, if you need to have multiple handlers (for example, because you have multiple threads), then you should create multiple Unmarshallers.


isValidating

public boolean isValidating()
            throws JAXBException
Sets whether the Unmarshaller is validating the objects that it reads. The default is false.
Returns:
True, if the Unmarshaller is validating the objects that it reads, false otherwise.
Throws:
JAXBException - Fetching the property value failed.

setEventHandler

public void setEventHandler(ValidationEventHandler pHandler)
            throws JAXBException
An application may customize the Unmarshallers behaviour in case of validation problems by supplying a custom handler for validation events. The default handler will trigger an exception in case of errors and fatal errors.
Parameters:
pHandler - The custom event handler or null to restore the default event handler.
Throws:
JAXBException - Setting the handler failed.

setProperty

public void setProperty(String pName,
                        Object pValue)
            throws PropertyException
Sets the unmarshaller property pName to the value pValue. Note, that the value type depends on the property being set.
Parameters:
pName - The property name.
Throws:
PropertyException - An error occurred while processing the property.

setValidating

public void setValidating(boolean pValidating)
            throws JAXBException
Sets whether the Unmarshaller is validating the objects that it reads. The default is false.

Note: A validating unmarshaller will rarely use a validating SAX parser by default! It does so, because the SAX parsers validation and the Unmarshallers builtin validation would most probably validate the same things, resulting in no additional safety at the cost of wasting performance. Second, a SAX parser is not always in use. For example, you do not need a parser when converting a DOM Node. If you insist in a validating XML parser, then you should create your own org.xml.sax.XMLReader and use the method unmarshal(javax.xml.transform.Source).

Parameters:
pValidating - Whether the Unmarshaller should validate or not.
Throws:
JAXBException - Setting the property failed.

unmarshal

public java.lang.Object unmarshal(InputSource pSource)
            throws JAXBException
The Unmarshaller reads the byte stream or character stream referred by the org.xml.sax.InputSource and converts it into an equivalent JAXB object.
Parameters:
pSource - The InputSource referring to a byte or character stream. It is recommended, that the system ID is set. This may be required, if the XML in the stream refers to external entities.
Returns:
The JAXB object read from the byte or character stream.
Throws:
JAXBException - An unexpected problem (for example an IOException) occurred.

unmarshal

public java.lang.Object unmarshal(Node pNode)
            throws JAXBException
The Unmarshaller converts the given node into an equivalent JAXB object.
Parameters:
pNode - The node to convert. The JAXB provider must support documents and elements. Other node types may not work (document fragments) or cannot work (attributes, text nodes, and so on).
Returns:
The JAXB object read from the DOM node.
Throws:
JAXBException - An unexpected problem occurred.

unmarshal

public java.lang.Object unmarshal(Source pSource)
            throws JAXBException
The Unmarshaller reads the XML representation from the given Source and converts it into an equivalent JAXB object.

The JAXB provider must support at least javax.xml.transform.sax.SAXSource, javax.xml.transform.dom.DOMSource, and javax.xml.transform.stream.StreamSource. A possible implementation could validate whether the argument is actually an instance of these subinterfaces. If so, it might simply act like getUnmarshallerHandler(), unmarshal(org.w3c.dom.Node), unmarshal(InputStream), or unmarshal(org.xml.sax.InputSource), respectively.

Note: If you are not using the standard JAXP mechanism for obtaining an org.xml.sax.XMLReader, then you might create your own SAX parser and invoke the pSource arguments javax.xml.transform.sax.SAXSource.setXMLReader(org.xml.sax.XMLReader). The JAXB provider will detect and use your SAX parser.

Parameters:
pSource - The Source being read.
Returns:
The JAXB object read from the DOM node.
Throws:
JAXBException - An unexpected problem occurred.

unmarshal

public java.lang.Object unmarshal(java.io.File pFile)
            throws JAXBException
This method takes opens the given file pFile for input. The Unmarshaller reads the byte stream contained in the file and converts it into an equivalent JAXB object.
Parameters:
pFile - The file being read.
Returns:
The JAXB object read from the file.
Throws:
JAXBException - An unexpected problem (for example an IOException) occurred.

unmarshal

public java.lang.Object unmarshal(java.io.InputStream pStream)
            throws JAXBException
The Unmarshaller reads the given byte stream and converts it into an equivalent JAXB object.
Parameters:
pStream - The stream being read.
Returns:
The JAXB object read from the byte stream.
Throws:
JAXBException - An unexpected problem (for example an IOException) occurred.

unmarshal

public java.lang.Object unmarshal(java.net.URL pURL)
            throws JAXBException
This method takes connects to the given pURL and opens a byte stream for input. The Unmarshaller reads the byte stream and converts it into an equivalent JAXB object.
Parameters:
pURL - The URL being read.
Returns:
The JAXB object read from the URL.
Throws:
JAXBException - An unexpected problem (for example an IOException) occurred.