LookupServlet.java

package org.oddjob.webapp.servlets;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.oddjob.Oddjob;
import org.oddjob.OddjobLookup;
import org.oddjob.arooa.standard.StandardArooaSession;
import org.oddjob.monitor.context.ExplorerContext;
import org.oddjob.monitor.model.ExplorerContextImpl;
import org.oddjob.monitor.model.ExplorerModelImpl;
import org.oddjob.util.SimpleThreadManager;
import org.oddjob.util.ThreadManager;
import org.oddjob.webapp.WebappConstants;
import org.oddjob.webapp.model.IconRegistry;
import org.oddjob.webapp.model.JobInfoLookup;


/**
 * This servlet creates a JobInfoLookup on an Oddjob instance which tracks
 * changes in the Oddjob so that the detail is available for presentation.
 *  
 * @author Rob Gordon.
 */

public class LookupServlet extends HttpServlet {
	private static final long serialVersionUID = 20051103;
	private static final Logger logger = Logger.getLogger(LookupServlet.class);
	
	/** The lookup this instance creates. */
	private JobInfoLookup lookup;

	private ThreadManager threadManager;
	
	/*
	 *  (non-Javadoc)
	 * @see javax.servlet.Servlet#init(javax.servlet.ServletConfig)
	 */
	public void init(ServletConfig config) throws ServletException {		
		ServletContext context = config.getServletContext();
						
		Oddjob oddjob = (Oddjob) context.getAttribute(
				WebappConstants.ODDJOB_INSTANCE); 
		if (oddjob == null) {
			throw new ServletException("No Oddjob Instance - ensure Oddjob Servlet starts first!");
		}
		
		String logFormat = context.getInitParameter(
				WebappConstants.LOG_FORMAT_PARAM);
		if (logFormat== null) {
			logFormat= config.getInitParameter(
					WebappConstants.LOG_FORMAT_PARAM);
		}
				
		String root = context.getInitParameter(
				WebappConstants.ROOT_PARAM);
		if (root == null) {
			root = config.getInitParameter(WebappConstants.ROOT_PARAM);
		}
		
		threadManager = new SimpleThreadManager();
		
		ExplorerModelImpl explorerModel = new ExplorerModelImpl(
				new StandardArooaSession());
		explorerModel.setLogFormat(logFormat);
		explorerModel.setThreadManager(threadManager);
		explorerModel.setOddjob(oddjob);
		
		ExplorerContext eContext = new ExplorerContextImpl(explorerModel);
		
		Object rootNode = oddjob;
		if (root != null) {
			while (true) {
				OddjobLookup lookup = new OddjobLookup(oddjob);
				rootNode = lookup.lookup(root);
		
				if (rootNode != null) {
					break;
				}
				logger.debug("Waiting for oddjob to create [" + root + "]");
				synchronized (this) {
					try {
						wait(1000);
					} catch (InterruptedException e) {
						return;
					}
				}
			}
			
			eContext = eContext.addChild(rootNode);
		}
				
		lookup = new JobInfoLookup((IconRegistry)
				context.getAttribute(WebappConstants.ICON_REGISTRY));
		
		lookup.setRoot(rootNode, eContext);
		
		context.setAttribute(WebappConstants.DETAIL_LOOKUP, lookup);
	}

	/*
	 *  (non-Javadoc)
	 * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
	 */
	public void doGet(HttpServletRequest req, HttpServletResponse res)
	throws ServletException, IOException {
		res.setContentType("text/plain");
		PrintWriter out = res.getWriter();		
		out.println("Lookup");
	}

	/*
	 *  (non-Javadoc)
	 * @see javax.servlet.Servlet#destroy()
	 */
	public void destroy() {
		threadManager.close();
		lookup.destroy();
	}
}