info.kwarc.sally4.docmanager.impl.MessageParserImpl Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of sally4-docmanager Show documentation
The newest version!
package info.kwarc.sally4.docmanager.impl;

import info.kwarc.sally4.docmanager.MessageParser;

import java.io.StringReader;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;

import org.apache.camel.converter.jaxb.JaxbDataFormat;
import org.apache.felix.ipojo.annotations.Component;
import org.apache.felix.ipojo.annotations.Instantiate;
import org.apache.felix.ipojo.annotations.Provides;
import org.apache.felix.ipojo.annotations.Validate;
import org.apache.felix.ipojo.extender.Extender;
import org.osgi.framework.Bundle;
import org.osgi.framework.wiring.BundleWiring;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Component
@Instantiate
@Provides(specifications=MessageParser.class)
@Extender(
		onArrival="onBundleArrival",
		onDeparture="onBundleDeparture",
		extension="Comm-Package")
public class MessageParserImpl implements MessageParser {
	public final static Pattern xmlNamespace = Pattern.compile("xmlns(:(\\w+))?=\"http://kwarc.info/sally/comm/([\\w/:.]+)\"");
	final String packagePrefix = "info.kwarc.sally.comm";

	class MessageMarshallers {
		JAXBContext context;
		Marshaller marshaller;
		Unmarshaller unmarshaller;

		public MessageMarshallers(JAXBContext context) {
			this.context = context;
			try {
				marshaller = context.createMarshaller();
				unmarshaller  = context.createUnmarshaller();
			} catch (JAXBException e) {
				e.printStackTrace();
			}
		}

		public JAXBContext getContext() {
			return context;
		}

		public Marshaller getMarshaller() {
			return marshaller;
		}

		public Unmarshaller getUnmarshaller() {
			return unmarshaller;
		}
	}

	Logger log;

	HashMap bundleMappings = new HashMap();

	/* (non-Javadoc)
	 * @see info.kwarc.sally4.docmanager.impl.MessageParser1#getFormat(java.lang.String)
	 */
	@Override
	public JaxbDataFormat getFormat(String commType) {
		return new JaxbDataFormat(bundleMappings.get(commType).getContext());
	}

	/* (non-Javadoc)
	 * @see info.kwarc.sally4.docmanager.impl.MessageParser1#getUnmarshaller(java.lang.String)
	 */
	@Override
	public Unmarshaller getUnmarshaller(String schemaType) {
		if (!bundleMappings.containsKey(schemaType))
			return null;
		return bundleMappings.get(schemaType).getUnmarshaller();
	}

	/* (non-Javadoc)
	 * @see info.kwarc.sally4.docmanager.impl.MessageParser1#getMarshaller(java.lang.String)
	 */
	@Override
	public Marshaller getMarshaller(String schemaType) {
		if (!bundleMappings.containsKey(schemaType))
			return null;
		return bundleMappings.get(schemaType).getMarshaller();
	}

	public static String getMessageSchema(String xmlMessage) {
		Matcher m = xmlNamespace.matcher(xmlMessage);
		if (m.find()) {
			return m.group(3);
		} else
			return null;
	}

	/* (non-Javadoc)
	 * @see info.kwarc.sally4.docmanager.impl.MessageParser1#validMessageSchemaDefinition(java.lang.String)
	 */
	@Override
	public boolean validMessageSchemaDefinition(String iface) {
		return bundleMappings.containsKey(iface);
	}

	public  T parseAs(String xmlMessage, Class resultClass) {
		String msgType = getMessageSchema(xmlMessage);
		if (!bundleMappings.containsKey(msgType))
			return null;
		StringReader r = new StringReader(xmlMessage);
		try {
			Object o = bundleMappings.get(msgType).getUnmarshaller().unmarshal(r);
			if (resultClass.isAssignableFrom(o.getClass())) {
				return (T) o;
			} 
		} catch (JAXBException e) {
			e.printStackTrace();
		}
		return null;
	}

	public MessageParserImpl() {
		log = LoggerFactory.getLogger(getClass());		
	}

	@Validate
	void start() {
		try {
			// Make sure core is always there
			bundleMappings.put("core", new MessageMarshallers(JAXBContext.newInstance("info.kwarc.sally.comm.core", getClass().getClassLoader())));
		} catch (JAXBException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}		
	}

	void onBundleArrival(Bundle bundle, String header) {
		log.info("Looking at message definitions in bundle "+bundle.getSymbolicName());
		for (String iFace : header.split(",")) {
			try {
				JAXBContext context = JAXBContext.newInstance(packagePrefix+"."+iFace, bundle.adapt(BundleWiring.class).getClassLoader());
				bundleMappings.put(iFace, new MessageMarshallers(context));
				log.info("Successfully loaded "+iFace);
			} catch (JAXBException e) {
				log.error(e.getMessage());
				e.printStackTrace();
			}
		}
	}

	void onBundleDeparture(Bundle bundle) {
		bundleMappings.remove(bundle);
	}

	@Override
	public String marshall(Object obj) {
		String pkg = obj.getClass().getPackage().getName();
		if (!pkg.startsWith(packagePrefix))
			return null;
		String schema = pkg.substring(packagePrefix.length()+1);
		Marshaller marshaller = getMarshaller(schema);
		if (marshaller == null)
			return null;
		StringWriter output = new StringWriter();
		try {
			marshaller.marshal(obj, output);
		} catch (JAXBException e) {
			e.printStackTrace();
			return null;
		}
		return output.toString();
	}

}