Java Filter Source Code Example CountUniqueEventsFilter

package com.eventgnosis.filters;
 
/************************************************************************
 *
 * Confidential and Proprietary Information of EventGnosis, Inc.
 *
 * Copyright 2002-2007 by EventGnosis, Inc. - All Rights Reserved.
 *
 * Affixing of the above copyright notice does not in itself constitute  
 * publication or intended publication of these confidential materials.  
 *   
 ************************************************************************
 *                                                                       
 * Name: CountUniqueEventsFilter.java
 * 
 * Description: count unique events based on a fieldname. 
 * 
 * If event matches %Condition%, for each unique value of %FieldName%, 
 * perform %ActionList% if count reaches %Threshold% within %TimeInterval%.
 *
 * NOTE: 
 *
 * Bugs: 
 * Notes: None
 *  
 ************************************************************************
 *
 **/
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import com.eventgnosis.config.ConfigurationManager;
import com.eventgnosis.config.EmmlConfig;
import com.eventgnosis.system.SystemObject;
import com.eventgnosis.types.Event;
import com.eventgnosis.types.XmlRep;
import com.eventgnosis.util.Log;
import com.eventgnosis.util.Util;
 
public final class CountUniqueEventsFilter extends FilterBase {
	private HashMap<String, CountUniqueRec> uniqueMap = new HashMap<String, CountUniqueRec>(); // holds countRecs by fieldName value keep track of prior event
	private String idFieldName = null; // the unique fieldName to catalog
	private long threshold = 0; // if count exceeds this # w/in time interval, set field to expression
	private TimeInterval timeInterval = null; // look at count over this time interval from start of event occurrence
	private ActionList actionList = null; // perform this list if threshold exceeded w/in time interval for each event
 
	public void setVars( Log log, String name, SystemObject myMgr, ConfigurationManager configMgr, EmmlConfig eCfg ) {
		super.setVars( log, name, myMgr, configMgr, eCfg );
		if ( eCfg != null ) {
			setCondition( eCfg ); // build selection list from filter's XML def
			// get field name on which to ID uniqueness. Set to "" if not specified.
			if ( ( idFieldName = (String) eCfg.getParmObject( "FieldName", 0 ) ) == null ) {
				idFieldName = ""; // default unique ID if missing
			}
			double dThreshold = Util.strToDouble( (String) eCfg.getParmObject( "Threshold", 0 ) );
			threshold = Util.isDoubleError( dThreshold ) ? 0 : (long) ( dThreshold + 0.5 ); // round up for counting events
			if ( ( ( timeInterval = (TimeInterval) eCfg.getParmObject( "TimeInterval", 0 ) ) == null ) || ( timeInterval.getMsecs() <= 0 ) ) {
				timeInterval = TimeInterval.getDefault();
			}
			setExpirationTime( timeInterval.getMsecs() ); // cleanup time
			if ( ( actionList = (ActionList) eCfg.getParmObject( "ActionList", 0 ) ) == null ) {
				actionList = ActionList.getDefault(); 
			}
		}
	}
 
	// look for events that match condition. Insert into count map by fieldName id value
	// and if count for that id has exceeded the threshold, write an expression into
	// the specified new event field.
	public ArrayList processEvent( Event ev ) {
		ArrayList evRoutingList = super.processEvent( ev ); // get stdout first (is mandatory)
		//	 see if current event matches selection criteria & not disabled
		if ( ( ev != null ) && ( threshold > 0 ) && ( matchCondition( ev ) ) ){
			XmlRep xr = ev.getXml(); // get the fieldName=value representation from the current event
			String currId = ( ( idFieldName.length() > 0 ) && ( xr != null ) && ( xr.getPropertyValue( idFieldName ) != null ) ) ? xr.getPropertyValue( idFieldName ) : "";// use currId of "" if any problems with original id or getting value
			CountUniqueRec countRec = (CountUniqueRec) uniqueMap.get( currId ); // lookup currId state
			if ( countRec == null ) { // if null doesn't exist yet
				countRec = new CountUniqueRec( timeInterval.getMsecs() );
				uniqueMap.put( currId, countRec );
			}
			if ( countRec.isExpired() ) { // guaranteed to exist now, see if it's expired
				countRec.reset();
			}
			countRec.incrementCount(); // unconditionally increment
			
			if ( countRec.getCount() >= threshold ) { // if reached threshold w/in TimeInterval
				String errors = actionList.perform( ev, evRoutingList, this ); // perform actions on the event and possibly create new events to be routed
				if ( errors != null ) {
					getLog().err( getName() + " error performing actionList!" );
				}
				countRec.reset(); // reset interval
			}
		}
		deleteExpired( uniqueMap ); // cleanup out expired entries
		return ( evRoutingList ); // Return one or more events and their destinations (e.g. original event going to next filter in the stack, and zero or more action events)
	}
 
//build XML pertaining to configuration for use and display in ORION Debugger
	public String getConfigXml() 	{
		String xml = super.getConfigXml(); // id info
		xml += ( getCondition() == null ) ? "" : getCondition().getConfigXml();
		xml += Util.toEmmlParmXml( "FieldName", idFieldName );
		xml += Util.toEmmlParmXml( "Threshold", Long.toString( threshold ) );
		xml += Util.toEmmlParmXml( "TimeInterval", timeInterval.getConfigXml() );
		xml += Util.toEmmlParmXml( "ActionList", actionList.getConfigXml() );
		return ( Util.toXml( "filter", xml ) );
	}
 
//build XML pertaining to runtime for use and display in ORION Debugger
	public String getRuntimeXml() 	{
		String xml = super.getRuntimeXml(); // id info
		if ( uniqueMap != null ) {
			Iterator iter = uniqueMap.keySet().iterator();
			while ( iter.hasNext() ) {
				String key = (String) iter.next();
				CountUniqueRec cuRec = (CountUniqueRec) uniqueMap.get( key );
				xml += Util.toXml( "countRec", ( Util.toXml( "id", key ) + cuRec == null ? "" : cuRec.getRuntimeXml() ) );
			}
		}
		return ( Util.toXml( "filter", xml ) );
	}
}