BMIModuleEventHandler.java

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package com.buglabs.bug.bmi;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;

import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.service.log.LogService;

import com.buglabs.bug.bmi.api.BMIModuleProperties;
import com.buglabs.bug.bmi.api.IModlet;
import com.buglabs.bug.bmi.api.IModletFactory;
import com.buglabs.util.osgi.LogServiceUtil;

/**
 * Manages logic of receiving messages from BMI and making changes to runtime.
 * runtime.
 * 
 * @author ken
 * 
 */
public class BMIModuleEventHandler {
	private static LogService logService;

	private static Map<String, List<IModletFactory>> modletFactories;

	private static Map<String, List<IModlet>> activeModlets;

	/**
	 * @return Map of active IModlets
	 */
	public static Map<String, List<IModlet>> getActiveModlets() {
		return activeModlets;
	}

	private final BundleContext context;

	/**
	 * @param context BundleContext
	 * @param logService log service
	 * @param modletFactories map of modlet factories
	 * @param activeModlets map of active modlets
	 */
	protected BMIModuleEventHandler(BundleContext context, LogService logService, Map<String, List<IModletFactory>> modletFactories, Map<String, List<IModlet>> activeModlets) {
		BMIModuleEventHandler.logService = logService;
		BMIModuleEventHandler.modletFactories = modletFactories;
		BMIModuleEventHandler.activeModlets = activeModlets;
		this.context = context;
	}

	/**
	 * This method is responsible for loading and starting any bundles that
	 * provide Modlets for given module type.
	 * 
	 * After bundle(s) are started, those bundles expose IModulet services. The
	 * BMI activator then listens for modlets. Upon new modlet creation, the
	 * setup is called.
	 * 
	 * @param event event to handle
	 */
	public void handleEvent(BMIModuleEvent event) {
		if (!modletFactories.containsKey(event.getModuleId())) {
			logService.log(LogService.LOG_ERROR, "No modlet factories support module, aborting event: " + event.getModuleId());
			return;
		}
		
		try {
			List<IModlet> ml;
			switch (event.getType()) {
			case INSERT:

				for (IModletFactory mf : modletFactories.get(event.getModuleId())) {
					IModlet m = mf.createModlet(context, event.getSlot(), event.getBMIDevice());
					try {
						m.setup();
					} catch (Exception e) {
						logService.log(LogService.LOG_ERROR, "Unable to setup Modlet " + mf.getName() + ": " + e.getMessage(), e);
						continue;
					}

					m.start();
					logService.log(LogService.LOG_INFO, "Started modlet from factory " + mf.getName() + "...");

					// Add this model to our map of running Modlets.
					if (!activeModlets.containsKey(m.getModuleId())) {
						activeModlets.put(m.getModuleId(), new CopyOnWriteArrayList<IModlet>());
					}

					List<IModlet> am = activeModlets.get(m.getModuleId());

					if (!am.contains(m)) {
						am.add(m);
					}
				}

				break;
			case REMOVE:
				List<IModlet> removalList = new ArrayList<IModlet>();
				ml = activeModlets.get(event.getModuleId());
				for (IModlet m : ml) {	
					if (m.getSlotId() == event.getSlot()) {
						logService.log(LogService.LOG_INFO, "Stopping modlet " + m.getModuleId() + "...");
						m.stop();
						removalList.add(m);
					}
				}

				for (IModlet m : removalList) 
					ml.remove(m);
				
				removalList.clear();
				logService.log(LogService.LOG_INFO, "Modlet removal complete.");
			
				break;
			}
		} catch (BundleException e) {
			logService.log(LogService.LOG_ERROR
					, "Bundle/Modlet error occurred: " + e.getClass().getName() + ", " + e.getMessage());
			StringWriter sw = new StringWriter();
			e.printStackTrace(new PrintWriter(sw));
			logService.log(LogService.LOG_ERROR, sw.getBuffer().toString());

			if (e.getNestedException() != null) {
				logService.log(LogService.LOG_ERROR
						, "Nested Exception: " + e.getNestedException().getClass().getName() + ", " + e.getNestedException().getMessage());
			}

			e.printStackTrace();
		} catch (Exception e) {
			logService.log(LogService.LOG_ERROR
					, "Bundle/Modlet error occurred: " + e.getClass().getName() + ", " + e.getMessage());
			StringWriter sw = new StringWriter();
			e.printStackTrace(new PrintWriter(sw));
			logService.log(LogService.LOG_ERROR, sw.getBuffer().toString());
		}
	}
}