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Extending the framework
AccessAO, AccessAOBuilder ¿ PQL Documentation
GenericPush and GenericPull
New Wrapper
Transport Handler
Push
To implement a Push Transport Handler (a transport handler that receives data instead of requests) an AbstractPushTransportHandler has to be extended. Only a few methods have to be implemented like the send method that transfers data to source or target of the transport, the getName method which returns the unique name of this transport handler, and the create instance method which creates a new instance of this transport handler with the given options. Further, ones has to implement the process open and process close methods. These methods are used to open or close the transport channel depending on the exchange pattern of the transport handler. There are 8 possible transport pattern based on the Message Exchange Pattern (MEP) namely they are: InOnly, RobustInOnly, InOut, InOptionalOut, OutOnly, RobustOutOnly, OutIn, and OutOptionalIn.
public class ExampleTransportHandler extends AbstractPushTransportHandler {
/** Logger */
private Logger LOG = LoggerFactory.getLogger(ExampleTransportHandler.class);
public ExampleTransportHandler() {
super();
}
public ExampleTransportHandler(IProtocolHandler<?> protocolHandler) {
super(protocolHandler);
}
@Override
public void send(byte[] message) throws IOException {
}
@Override
public ITransportHandler createInstance(
IProtocolHandler<?> protocolHandler, Map<String, String> options) {
ExampleTransportHandler handler = new ExampleTransportHandler(
protocolHandler);
// Set options
return handler;
}
@Override
public String getName() {
return "Example";
}
@Override
public void processInOpen() throws IOException {
}
@Override
public void processOutOpen() throws IOException {
}
@Override
public void processInClose() throws IOException {
}
@Override
public void processOutClose() throws IOException {
}
@Override
public ITransportExchangePattern getExchangePattern() {
return ITransportExchangePattern.InOnly;
}
Pull
The implementation of a Pull Transport Handler is similar to the Push Transport Handler except the fact that ones has to implement the two methods getInputStream and getOutputStream that are used by a protocol handler to request the next data element.
public class ExampleTransportHandler extends AbstractPullTransportHandler {
/** Logger */
private Logger LOG = LoggerFactory.getLogger(ExampleTransportHandler.class);
private InputStream in;
private outputStrem out;
public ExampleTransportHandler() {
super();
}
public ExampleTransportHandler(IProtocolHandler<?> protocolHandler) {
super(protocolHandler);
}
@Override
public void send(byte[] message) throws IOException {
}
@Override
public ITransportHandler createInstance(
IProtocolHandler<?> protocolHandler, Map<String, String> options) {
SpeechTransportHandler handler = new SpeechTransportHandler(
protocolHandler);
// Set options
return handler;
}
@Override
public String getName() {
return "Example";
}
@Override
public void processInOpen() throws IOException {
}
@Override
public void processOutOpen() throws IOException {
}
@Override
public void processInClose() throws IOException {
}
@Override
public void processOutClose() throws IOException {
}
@Override
public InputStream getInputStream() {
return in;
}
@Override
public OutputStream getOutputStream() {
return out;
}
@Override
public ITransportExchangePattern getExchangePattern() {
return ITransportExchangePattern.InOnly;
}
Protocol Handler
public class ExampleProtocolHandler<T> extends AbstractProtocolHandler<T> {
public ExampleProtocolHandler() {
super();
}
public ExampleProtocolHandler(ITransportDirection direction,
IAccessPattern access) {
super(direction, access);
}
@Override
public void open() throws UnknownHostException, IOException {
getTransportHandler().open();
}
@Override
public void close() throws IOException {
getTransportHandler().close();
}
@Override
public boolean hasNext() throws IOException {
return true;
}
@Override
public T getNext() throws IOException {
return getDataHandler().readData("data");
}
@Override
public void write(T object) throws IOException {
}
@Override
public IProtocolHandler<T> createInstance(ITransportDirection direction,
IAccessPattern access, Map<String, String> options,
IDataHandler<T> dataHandler, ITransferHandler<T> transfer) {
ExampleProtocolHandler<T> instance = new ExampleProtocolHandler<T>(direction,
access);
instance.setDataHandler(dataHandler);
instance.setTransfer(transfer);
return instance;
}
@Override
public String getName() {
return "Example";
}
@Override
public ITransportExchangePattern getExchangePattern() {
if (this.getDirection().equals(ITransportDirection.IN)) {
return ITransportExchangePattern.InOnly;
} else {
return ITransportExchangePattern.OutOnly;
}
}
@Override
public void onConnect(ITransportHandler caller) {
// TODO Auto-generated method stub
}
@Override
public void onDisonnect(ITransportHandler caller) {
// TODO Auto-generated method stub
}
@Override
public void process(ByteBuffer message) {
getTransfer().transfer(getDataHandler().readData(message));
}
}