ADB databinding in axis2 uses the ADBDatasource to return the OMElement.
Currently ADBDatasource getReader and serialize methods are like this.
public abstract void serialize(XMLStreamWriter xmlWriter)
throws XMLStreamException;
public XMLStreamReader getReader() throws XMLStreamException {
return bean.getPullParser(parentQName);
}
When we want to serialize the xml stream directly to transport we use
serialize method and the getReader is used in building the OMElemnet.
Specially Rampart module always build the OMElement and hence call for
getReader() method.
The serialize method is worked fine and it is the well tested method in ADB
and the getReader method which uses the ADBXmlStremReader has some issue
regarding extension and binary handling.
To solve this problem I wrote OMElmentStreamWriter [1] which build the
OMElement from the writer.
So now the getReader method looks like this. It use the serialize method to
create the OMElement.
public XMLStreamReader getReader() throws XMLStreamException {
OMElementStreamWriter omElementStreamWriter = new
OMElementStreamWriter();
serialize(omElementStreamWriter);
return omElementStreamWriter.getOMElement().getXMLStreamReader();
}
this method perfectly works except the following two problems.
1. It is bit in efficient
OMElementStreamWriter first creates the OMElement and then it is used to get
the reader and again buid the OMElement.
To solve that either we can introduce a method to OMDataSource to directly
return the OMElement or AXIOM it self can use the above writer to build the
OMElement using the serilize method.
2. problems with the MTOM
This writer is not aware mtom. so it always serialize it as base64binary.
To fix this problem we can test for this pirticular writer in ADB generated
code (using instanceof or using a property) and set the data handler
to the element using a special method.
So this way we can create an OMElement which has a datahandler object in it.
in ADB bean class
if (writer instanceof OMElementStreamWriter){
(OMElementStreamWriter)writer).setDataHandler(dataHandler);
}
in OMElementStreamWriter
public void setDataHandler(DataHandler dataHandler){
OMText omText = omFactory.createOMText(dataHandler,true);
currentOMElement.addChild(omText);
}
would this solve our problem?
And can someone has a better knowledge with Axiom comment on these?
The main advantage ADB has from this is to use the well tested serialize
method and hence keep one method to serailize the bean.
thanks,
Amila.
[1]
https://svn.apache.org/repos/asf/webservices/axis2/trunk/java/modules/adb/src/org/apache/axis2/databinding/utils/writer/OMElementStreamWriter.java
--
Amila Suriarachchi,
WSO2 Inc.
