plugins/org.eclipse.epp.wizard/src/org/eclipse/epp/wizard/internal/StatsLogger.java

/*******************************************************************************
 * Copyright (c) 2008 Innoopract Informationssysteme GmbH.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Innoopract Informationssysteme GmbH - initial API and implementation
 ******************************************************************************/
package org.eclipse.epp.wizard.internal;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

import org.apache.log4j.Logger;

/**
 * Class for logging statistics about outgoing clicks Logged items: * current
 * timestamp * user agent * selected IU roots * destination URL
 * 
 * @author mwoelker
 */
public class StatsLogger implements Runnable {

  private static final String TABLE_HEADER = "'Timestamp    ipAdress    rootIUs	destination	user-agent";
  private static final Logger logger = Logger.getLogger( StatsLogger.class );
  /**
   * Class encapsulating data for one outgoing click
   * 
   * @author mwoelker
   */
  public static class Statistic {

    final static protected String ISO8601_DATEFORMAT = "yyyy-MM-dd'T'HH:mm:ss\t";
    final static protected DateFormat dateFormat = new SimpleDateFormat( ISO8601_DATEFORMAT );
    final protected Date timestamp = new Date();
    final protected String userAgent;
    final protected String roots;
    final protected String destination;
    final protected String ipAdress;

    public Statistic( String destination,
                      String userAgent,
                      String ipAdress,
                      String roots
                      )
    {
      super();
      this.destination = destination;
      this.userAgent = userAgent;
      this.ipAdress = ipAdress;
      this.roots = roots;
    }

    @Override
    public String toString() {
      StringBuilder builder = new StringBuilder();
      builder.append( dateFormat.format( timestamp ) );
      builder.append( ipAdress );
      builder.append( "\t" );
      builder.append( roots );
      builder.append( "\t" );
      builder.append( destination );
      builder.append( "\t" );
      builder.append( userAgent );
      return builder.toString();
    }
  }
  // Blocking queue for asynchronous producer/consumer processing
  protected BlockingQueue<Statistic> queue = new LinkedBlockingQueue<Statistic>();
  protected Thread thread;
  private PrintWriter writer;

  public StatsLogger( File file ) {
    try {
      writer = new PrintWriter( new BufferedWriter( new FileWriter( file, true ) ) );
      writer.println( TABLE_HEADER );
      thread = new Thread( this );
      thread.setName( "Download Statistics Logger" );
      thread.setDaemon( true );
      thread.start();
    } catch( Throwable t ) {
      logger.error( "Could not initialize StatsLogger", t );
    }
  }

  public void log( Statistic statistic ) {
    queue.add( statistic );
  }

  public void run() {
    try {
      while( true ) {
        Statistic statistic;
        statistic = queue.take();
        internalLog( statistic );
      }
    } catch( InterruptedException e ) {
      Thread.currentThread().interrupt();
    }
  }

  private void internalLog( Statistic statistic ) {
    writer.println( statistic );
    writer.flush();
  }
}