PropertyExprEvaluatorScalarIterable.java

/*
 * *************************************************************************************
 *  Copyright (C) 2008 EsperTech, Inc. All rights reserved.                            *
 *  http://esper.codehaus.org                                                          *
 *  http://www.espertech.com                                                           *
 *  ---------------------------------------------------------------------------------- *
 *  The software in this package is published under the terms of the GPL license       *
 *  a copy of which has been included with this distribution in the license.txt file.  *
 * *************************************************************************************
 */

package com.espertech.esper.epl.enummethod.dot;

import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventPropertyGetter;
import com.espertech.esper.client.EventType;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.epl.expression.ExprEvaluatorEnumeration;
import com.espertech.esper.epl.expression.ExprValidationException;
import com.espertech.esper.event.EventAdapterService;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class PropertyExprEvaluatorScalarIterable implements ExprEvaluatorEnumeration {
    private static final Log log = LogFactory.getLog(PropertyExprEvaluatorScalarIterable.class);

    private final String propertyName;
    private final int streamId;
    private final EventPropertyGetter getter;
    private final Class componentType;

    public PropertyExprEvaluatorScalarIterable(String propertyName, int streamId, EventPropertyGetter getter, Class componentType) {
        this.propertyName = propertyName;
        this.streamId = streamId;
        this.getter = getter;
        this.componentType = componentType;
    }

    public Collection<EventBean> evaluateGetROCollectionEvents(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context) {
        return null;
    }

    public Collection evaluateGetROCollectionScalar(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context) {
        EventBean eventInQuestion = eventsPerStream[streamId];
        Object result = getter.get(eventInQuestion);
        if (result == null) {
            return null;
        }
        if (!(result instanceof Iterable)) {
            log.warn("Expected iterable-type input from property '" + propertyName + "' but received " + result.getClass());
            return null;
        }
        ArrayList items = new ArrayList();
        Iterator iterator = ((Iterable) result).iterator();
        for (;iterator.hasNext();)
        {
            items.add(iterator.next());
        }
        return items;
    }

    public EventType getEventTypeCollection(EventAdapterService eventAdapterService) {
        return null;
    }

    public Class getComponentTypeCollection() throws ExprValidationException {
        return componentType;
    }

    public EventType getEventTypeSingle(EventAdapterService eventAdapterService, String statementId) throws ExprValidationException {
        return null;
    }

    public EventBean evaluateGetEventBean(EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext context) {
        return null;
    }
}