MSMQSender

package com.trendmicro.grid.acl.ds.msmq;

import net.sf.tinyjee.streams.ByteBufferOutputStream;
import net.sf.tinyjee.util.FileUtils;
import org.w3c.dom.*;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.UUID;

/**
 * This is a simple wrapper for a XML formatted MSMQ SOAP Request used to send message to MSMQ.
 *
 * @author juergen_kellerer, werner_watzka, 2010-06-02
 * @version 1.0
 */
public class MSMQSender implements Sender {

	static final long MS_PER_MONTH = 30 * 24 * 60 * 60 * 1000L;

	static final UUID sourceQMGuid = UUID.randomUUID(); // specifies the machine ID
	static final Document template;
	static final DateFormat dateFormatTemplate = new SimpleDateFormat("yyyyMMdd'T'HHmmss");

	static {
		try {
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			factory.setNamespaceAware(true);
			DocumentBuilder builder = factory.newDocumentBuilder();
			template = builder.parse(MSMQSender.class.getResourceAsStream("/msmq-soap-send-template.xml"));

			// Setting the MachineID
			findFirstElement(template.getDocumentElement(), "Header", "Msmq", "SourceQmGuid").setTextContent(sourceQMGuid.toString());
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	static Element findFirstElement(Node startNode, String... path) {
		NodeList nl = startNode.getChildNodes();

		final int length = nl.getLength();
		for (int i = 0; i < length; i++) {
			final Node node = nl.item(i);

			if (!(node instanceof Element))
				continue;

			final Element el = (Element) node;
			if (path.length > 0 && !path[0].equals(el.getLocalName()))
				continue;

			if (path.length > 1) {
				String[] reducedPath = new String[path.length - 1];
				System.arraycopy(path, 1, reducedPath, 0, reducedPath.length);
				return findFirstElement(el, reducedPath);
			}

			return el;
		}

		// Do not return null, fail instead!
		throw new IllegalArgumentException("Didn't find the requested element " + Arrays.toString(path) + " inside " + startNode);
	}

	static String toMSMQPriority(int priority) {
		// TODO: Convert the given input prio (1: lowest, 10: highest, 5: normal)
		// TODO: to the priority system used by MSMQ.
		return String.valueOf(priority);
	}

	URI endpoint;
	String queueName;
	DateFormat dateFormat = (DateFormat) dateFormatTemplate.clone();    // NOSONAR - Cloning is safe to use and avoids parsing the
	//                                                                               format pattern more than once.

	Document message;
	Element headerElement, pathElement, propertiesElement, msmqElement;

	@Override
	public void reset(List<URI> endpoints, String queueName) {
		endpoint = endpoints.get(0);
		this.queueName = queueName;
		message = (Document) template.cloneNode(true);

		final Element rootElement = message.getDocumentElement();
		headerElement = findFirstElement(rootElement, "Header");
		pathElement = findFirstElement(headerElement, "path");
		propertiesElement = findFirstElement(headerElement, "properties");
		msmqElement = findFirstElement(headerElement, "Msmq");
	}

	@Override
	public void send(int priority, String messageBody) throws IOException {

		// TODO: finish / test

		URL url = new URL(endpoint.toURL(), queueName);
		HttpURLConnection huc = (HttpURLConnection) url.openConnection();
		huc.setRequestMethod("POST");
		huc.setDoOutput(true);

		send(priority, messageBody, huc.getOutputStream());

		if (huc.getResponseCode() != HttpURLConnection.HTTP_OK) {
			ByteBufferOutputStream bOut = new ByteBufferOutputStream();
			FileUtils.copy(huc.getErrorStream(), bOut);

			throw new IOException("Failed sending message to " + queueName +
					", caused by; HTTP-Response: " + huc.getResponseCode() + " " + huc.getResponseMessage() +
					"\nDetails:\n" + bOut.toString());
		}
	}

	void send(int priority, String messageBody, OutputStream out) throws IOException {

		// TODO: finish / test

		// Set routing.
		findFirstElement(pathElement, "to").setTextContent("MSMQ:DIRECT=OS:..???../" + queueName);
		findFirstElement(pathElement, "id").setTextContent("uuid:1000@" + UUID.randomUUID());

		// Set prio
		findFirstElement(msmqElement, "Priority").setTextContent(toMSMQPriority(priority));

		// Set dates
		long timeOffset = System.currentTimeMillis();
		findFirstElement(propertiesElement, "expiresAt").setTextContent(
				dateFormat.format(new Date(timeOffset + MS_PER_MONTH)));
		findFirstElement(propertiesElement, "sentAt").setTextContent(
				dateFormat.format(new Date(timeOffset)));
		findFirstElement(msmqElement, "TTrq").setTextContent(
				dateFormat.format(new Date(timeOffset)));

		// Add the message body
		CDATASection cdataSection = message.createCDATASection(messageBody);
		findFirstElement(message.getDocumentElement(), "Body").appendChild(cdataSection);

		// Serialize the XML to the output stream.
		try {
			Transformer tf = TransformerFactory.newInstance().newTransformer();
			tf.transform(new DOMSource(message), new StreamResult(out));
		} catch (TransformerException e) {
			throw new IOException(e);
		}
	}
}