private void performXSLT()

in modules/core/src/main/java/org/apache/synapse/mediators/transform/XSLTMediator.java [213:363]
117 lines of code
26 McCabe index (conditional complexity)

    private void performXSLT(MessageContext synCtx, SynapseLog synLog) {

        OMNode sourceNode = source.selectOMNode(synCtx, synLog);
        boolean isSoapEnvelope = (sourceNode == synCtx.getEnvelope());
        boolean isSoapBody = (sourceNode == synCtx.getEnvelope().getBody());
        boolean isSoapHeader = (sourceNode == synCtx.getEnvelope().getHeader());

        // Derive actual key from message context
        String generatedXsltKey = xsltKey.evaluateValue(synCtx);

        // get templates from generatedXsltKey
        Templates cachedTemplates = null;

        if (synLog.isTraceTraceEnabled()) {
            synLog.traceTrace("Transformation source : " + sourceNode.toString());
        }

        // determine if it is needed to create or create the template
        if (isCreationOrRecreationRequired(synCtx)) {
            // many threads can see this and come here for acquiring the lock
            synchronized (transformerLock) {
                // only first thread should create the template
                if (isCreationOrRecreationRequired(synCtx)) {
                    cachedTemplates = createTemplate(synCtx, synLog, generatedXsltKey);
                } else {
                    cachedTemplates = cachedTemplatesMap.get(generatedXsltKey);
                }
            }
        }
        else{
            //If already cached template then load it from cachedTemplatesMap
            synchronized (transformerLock){
                cachedTemplates = cachedTemplatesMap.get(generatedXsltKey);
            }
        }

        try {
            // perform transformation
            Transformer transformer = null;
            try {
                transformer = cachedTemplates.newTransformer();
            } catch (NullPointerException ex) {
                handleException("Unable to create Transformer using cached template", ex, synCtx);
            }
            if (!properties.isEmpty()) {
                // set the parameters which will pass to the Transformation
                applyProperties(transformer, synCtx, synLog);
            }

            transformer.setErrorListener(new ErrorListenerImpl(synLog, "XSLT transformation"));
            
            String outputMethod = transformer.getOutputProperty(OutputKeys.METHOD);
            String encoding = transformer.getOutputProperty(OutputKeys.ENCODING);

            if (synLog.isTraceOrDebugEnabled()) {
                synLog.traceOrDebug("output method: " + outputMethod
                        + "; encoding: " + encoding);
            }
            
            ResultBuilderFactory.Output output;
            if ("text".equals(outputMethod)) {
                synLog.traceOrDebug("Processing non SOAP/XML (text) transformation result");
                output = ResultBuilderFactory.Output.TEXT;
            } else if (isSoapEnvelope) {
                output = ResultBuilderFactory.Output.SOAP_ENVELOPE;
            } else {
                output = ResultBuilderFactory.Output.ELEMENT;
            }
            
            SynapseEnvironment synEnv = synCtx.getEnvironment();
            ResultBuilder resultBuilder =
                    resultBuilderFactory.createResultBuilder(synEnv, output);
            SourceBuilder sourceBuilder = sourceBuilderFactory.createSourceBuilder(synEnv);
            
            if (synLog.isTraceOrDebugEnabled()) {
                synLog.traceOrDebug("Using " + sourceBuilder.getClass().getName());
                synLog.traceOrDebug("Using " + resultBuilder.getClass().getName());
            }
            
            try {
                transformer.transform(sourceBuilder.getSource((OMElement)sourceNode),
                                      resultBuilder.getResult());
            } finally {
                sourceBuilder.release();
            }

            synLog.traceOrDebug("Transformation completed - processing result");

            // get the result OMElement
            OMElement result =
                resultBuilder.getNode(encoding == null ? null : Charset.forName(encoding));

            if (synLog.isTraceTraceEnabled()) {
                synLog.traceTrace("Transformation result : " + result.toString());
            }

            if (targetPropertyName != null) {
                // add result XML as a message context property to the message
                if (synLog.isTraceOrDebugEnabled()) {
                    synLog.traceOrDebug("Adding result as message context property : " +
                        targetPropertyName);
                }
                synCtx.setProperty(targetPropertyName, result);
            } else {
                if (synLog.isTraceOrDebugEnabled()) {
                    synLog.traceOrDebug("Replace " +
                        (isSoapEnvelope ? "SOAP envelope" : isSoapBody ? "SOAP body" : "node")
                        + " with result");
                }

                if (isSoapEnvelope) {
                    try {
                        synCtx.setEnvelope((SOAPEnvelope) result);
                    } catch (AxisFault ex) {
                        handleException("Unable to replace SOAP envelope with result", ex, synCtx);
                    }

                } else if (isSoapBody) {
                    for (Iterator itr = synCtx.getEnvelope().getBody().getChildElements();
                        itr.hasNext(); ) {
                        OMElement child = (OMElement) itr.next();
                        child.detach();
                    }

                    for (Iterator itr = result.getChildElements(); itr.hasNext(); ) {
                        OMElement child = (OMElement) itr.next();
                        synCtx.getEnvelope().getBody().addChild(child);
                    }

                } else if (isSoapHeader) {
                    for (Iterator itr = synCtx.getEnvelope().getHeader().getChildElements();
                         itr.hasNext();) {
						OMElement child = (OMElement) itr.next();
						child.detach();
					}

					for (Iterator itr = result.getChildElements(); itr.hasNext();) {
						OMElement child = (OMElement) itr.next();
						synCtx.getEnvelope().getHeader().addChild(child);
					}

                } else {
                    sourceNode.insertSiblingAfter(result);
                    sourceNode.detach();
                }
            }

        } catch (TransformerException e) {
            handleException("Error performing XSLT transformation using : " + xsltKey, e, synCtx);
        }
    }