blockimpl.java

来自「开源的axis2框架的源码。用于开发WEBSERVER」· Java 代码 · 共 452 行 · 第 1/2 页

    /* (non-Javadoc)
      * @see org.apache.axiom.om.OMDataSource#serialize(java.io.OutputStream, org.apache.axiom.om.OMOutputFormat)
      */
    public void serialize(OutputStream output, OMOutputFormat format) throws XMLStreamException {
        MTOMXMLStreamWriter writer = new MTOMXMLStreamWriter(output, format);
        serialize(writer);
        writer.flush();
    }

    /* (non-Javadoc)
      * @see org.apache.axiom.om.OMDataSource#serialize(java.io.Writer, org.apache.axiom.om.OMOutputFormat)
      */
    public void serialize(Writer writerTarget, OMOutputFormat format) throws XMLStreamException {
        MTOMXMLStreamWriter writer =
                new MTOMXMLStreamWriter(StAXUtils.createXMLStreamWriter(writerTarget));
        writer.setOutputFormat(format);
        serialize(writer);
        writer.flush();
    }

    /* (non-Javadoc)
      * @see org.apache.axiom.om.OMDataSource#serialize(javax.xml.stream.XMLStreamWriter)
      */
    public void serialize(XMLStreamWriter writer) throws XMLStreamException {
        outputTo(writer, true);
    }

    public OMElement getOMElement() throws XMLStreamException, WebServiceException {
        OMElement newOMElement = null;
        boolean consume = true;  // get the OM consumes the message
        if (consumed) {
            throw ExceptionFactory.makeWebServiceException(
                    Messages.getMessage("BlockImplErr1", this.getClass().getName()));
        }
        if (omElement != null) {
            newOMElement = omElement;
        } else if (busObject != null) {
            // Getting the reader does not destroy the BusinessObject
            busObject = _getBOFromBO(busObject, busContext, consume);
            XMLStreamReader newReader = _getReaderFromBO(busObject, busContext);
            StAXOMBuilder builder = new StAXOMBuilder(newReader);
            newOMElement = builder.getDocumentElement();
        }
        setConsumed(consume);
        return newOMElement;
    }

    /* (non-Javadoc)
      * @see org.apache.axis2.jaxws.message.Block#isConsumed()
      */
    public boolean isConsumed() {
        return consumed;
    }

    /**
     * Once consumed, all instance data objects are nullified to prevent subsequent access
     *
     * @param consume
     * @return
     */
    public void setConsumed(boolean consume) {
        if (consume) {
            this.consumed = true;
            busObject = null;
            busContext = null;
            omElement = null;
            if (log.isDebugEnabled()) {
                // The following stack trace consumes indicates where the message is consumed
                log.debug("Message Block Monitor: Action=Consumed");
                log.debug(JavaUtils.stackToString());
            }
        } else {
            consumed = false;
        }
    }

    public boolean isQNameAvailable() {
        return (qName != null);
    }

    public void outputTo(XMLStreamWriter writer, boolean consume)
            throws XMLStreamException, WebServiceException {
        if (consumed) {
            // In some scenarios, the message is written out after the service instance is invoked.
            // In these situations, it is preferable to simply ignore this block.
            if (this.getParent() != null && getParent().isPostPivot()) {
                _postPivot_outputTo(writer);
            }
            throw ExceptionFactory.makeWebServiceException(
                    Messages.getMessage("BlockImplErr1", this.getClass().getName()));
        }
        if (omElement != null) {
            if (consume) {
                omElement.serializeAndConsume(writer);
            } else {
                omElement.serialize(writer);
            }
        } else if (busObject != null) {
            busObject = _getBOFromBO(busObject, busContext, consume);
            _outputFromBO(busObject, busContext, writer);
        }
        setConsumed(consume);
        return;
    }

    /**
     * Called if we have passed the pivot point but someone wants to output the block. The actual
     * block implementation may choose to override this setting
     */
    protected void _postPivot_outputTo(XMLStreamWriter writer)
            throws XMLStreamException, WebServiceException {
        if (log.isDebugEnabled()) {
            QName theQName = isQNameAvailable() ? getQName() : new QName("unknown");
            log.debug("The Block for " + theQName +
                    " is already consumed and therefore it is not written.");
            log.debug("If you need this block preserved, please set the " + Constants
                    .SAVE_REQUEST_MSG + " property on the MessageContext.");
        }
        return;
    }

    /**
     * Called if we have passed the pivot point but someone wants to output the block. The actual
     * block implementation may choose to override this setting.
     */
    protected XMLStreamReader _postPivot_getXMLStreamReader()
            throws XMLStreamException, WebServiceException {
        if (log.isDebugEnabled()) {
            QName theQName = isQNameAvailable() ? getQName() : new QName("unknown");
            log.debug("The Block for " + theQName +
                    " is already consumed and therefore it is only partially read.");
            log.debug("If you need this block preserved, please set the " + Constants
                    .SAVE_REQUEST_MSG + " property on the MessageContext.");
        }
        QName qName = getQName();
        String text = "";
        if (qName.getNamespaceURI().length() > 0) {
            text = "<prefix:" + qName.getLocalPart() + " xmlns:prefix='" + qName.getNamespaceURI() +
                    "'/>";
        } else {
            text = "<" + qName.getLocalPart() + "/>";
        }
        StringReader sr = new StringReader(text);
        return StAXUtils.createXMLStreamReader(sr);
    }

    /**
     * @return true if the representation of the block is currently a business object. Derived classes
     *         may use this information to get information in a performant way.
     */
    protected boolean isBusinessObject() {
        return busObject != null;
    }

    public String traceString(String indent) {
        // TODO add trace string
        return null;
    }

    /**
     * The default implementation is to return the business object. A derived block may want to
     * override this class if the business object is consumed when read (thus the dervived block may
     * want to make a buffered copy) (An example use case for overriding this method is the
     * businessObject is an InputSource)
     *
     * @param busObject
     * @param busContext
     * @param consume
     * @return
     */
    protected Object _getBOFromBO(Object busObject, Object busContext, boolean consume) {
        return busObject;
    }


    /**
     * The derived class must provide an implementation that builds the business object from the
     * reader
     *
     * @param reader     XMLStreamReader, which is consumed
     * @param busContext
     * @return
     */
    protected abstract Object _getBOFromReader(XMLStreamReader reader, Object busContext)
            throws XMLStreamException, WebServiceException;

    /**
     * Get an XMLStreamReader for the BusinessObject The derived Block must implement this method
     *
     * @param busObj
     * @param busContext
     * @return
     */
    protected abstract XMLStreamReader _getReaderFromBO(Object busObj, Object busContext)
            throws XMLStreamException, WebServiceException;

    /**
     * Output Reader contents to a Writer. The default implementation is probably sufficient for most
     * derived classes.
     *
     * @param reader
     * @param writer
     * @throws XMLStreamException
     */
    protected void _outputFromReader(XMLStreamReader reader, XMLStreamWriter writer)
            throws XMLStreamException {
        Reader2Writer r2w = new Reader2Writer(reader);
        r2w.outputTo(writer);
    }

    /**
     * Output BusinessObject contents to a Writer.
     * Derived classes must provide this implementation
     * @param busObject
     * @param busContext
     * @param writer
     * @throws XMLStreamException
     * @throws WebServiceException
     */
    protected abstract void _outputFromBO(Object busObject, Object busContext,
                                          XMLStreamWriter writer)
            throws XMLStreamException, WebServiceException;
	
}