org.apache.axiom.ext.stax.datahandler
Interface DataHandlerWriter

All Known Implementing Classes:
XOPEncodingStreamWriter

public interface DataHandlerWriter

Extension interface for XMLStreamWriter implementations that can receive base64 encoded binary content as DataHandler objects. A stream writer implementing this extension may write the binary data as base64 encoded character data or using some optimization such as XOP/MTOM.

All the requirements specified in org.apache.axiom.ext.stax apply to this extension interface. In particular, a consumer MUST use XMLStreamWriter.getProperty(String) with the property name defined by PROPERTY to get a reference to this extension interface.

The interface defines two methods to write binary content, one that takes a DataHandler argument and one with a DataHandlerProvider argument. The first should be used when the content is immediately available, while the second supports deferred loading of the data handler. The meaning of the contentID and optimize arguments is the same for both methods:

contentID
A content ID of the binary content, if available. The semantics of this argument are similar to those defined for the return value of the DataHandlerReader.getContentID() method:
optimize
Specifies if binary content is eligible for optimization (e.g. using XOP) or if it should be serialized as base64. This is only an indication and the implementation MAY choose to override this value or ignore it entirely.
Instead of interacting directly with this extension interface, the consumer may use the XMLStreamWriterUtils.writeDataHandler(javax.xml.stream.XMLStreamWriter, DataHandler, String, boolean) or XMLStreamWriterUtils.writeDataHandler(javax.xml.stream.XMLStreamWriter, DataHandlerProvider, String, boolean) utility methods. These methods make the processing of binary data entirely transparent for the caller.


Field Summary
static String PROPERTY
          The name of the property used to look up this extension interface from a XMLStreamWriter implementation.
 
Method Summary
 void writeDataHandler(DataHandlerProvider dataHandlerProvider, String contentID, boolean optimize)
          Write binary content to the stream.
 void writeDataHandler(DataHandler dataHandler, String contentID, boolean optimize)
          Write binary content to the stream.
 

Field Detail

PROPERTY

static final String PROPERTY
The name of the property used to look up this extension interface from a XMLStreamWriter implementation.

Method Detail

writeDataHandler

void writeDataHandler(DataHandler dataHandler,
                      String contentID,
                      boolean optimize)
                      throws IOException,
                             XMLStreamException
Write binary content to the stream. The implementation may choose to write the data as base64 encoded character data or using an optimization protocol such as XOP/MTOM.

Parameters:
dataHandler - the binary content to write
contentID - an existing content ID for the binary data (see above)
optimize - indicates whether the content is eligible for optimization (see above)
Throws:
IOException - if an error occurs while reading from the data handler
XMLStreamException - if an error occurs while writing to the underlying stream

writeDataHandler

void writeDataHandler(DataHandlerProvider dataHandlerProvider,
                      String contentID,
                      boolean optimize)
                      throws IOException,
                             XMLStreamException
Write binary content to the stream. This method allows the implementation to defer loading of the content. More precisely, if the implementation decides to use an optimization scheme such as XOP, then the content will not be written immediately to the underlying stream, but only after the XML infoset is complete. If the caller uses this method, the implementation can defer the actual loading of the binary content.

Parameters:
dataHandlerProvider - the binary content to write
contentID - an existing content ID for the binary data (see above)
optimize - indicates whether the content is eligible for optimization (see above)
Throws:
IOException - If an error occurs while reading from the data handler. Since the implementation is free to override the supplied optimize argument, it may attempt to load the binary data immediately. Because this operation may fail, the method must declare this exception.
XMLStreamException - if an error occurs while writing to the underlying stream


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