platform/southbound/mqtt/smart-topic-device/src/main/java/org/eclipse/sensinact/gateway/sthbnd/mqtt/smarttopic/processor/ProcessorUtil.java

/*
* Copyright (c) 2020 Kentyou.
 * 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:
*    Kentyou - initial API and implementation
 */
package org.eclipse.sensinact.gateway.sthbnd.mqtt.smarttopic.processor;

import org.eclipse.sensinact.gateway.sthbnd.mqtt.smarttopic.processor.selector.Selector;
import org.eclipse.sensinact.gateway.sthbnd.mqtt.smarttopic.processor.selector.SelectorIface;

import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

/**
 * Utility method used by the processor to interpolate messages
 *
 * @author <a href="mailto:Jander.BOTELHODONASCIMENTO@cea.fr">Jander Botelho do Nascimento</a>
 */
public class ProcessorUtil {
    /**
     * This method transforms processor string property  in a list of selectors with its respective expression to be interpreted. e.g. 'array$0,json$name,'
     *
     * @param payload
     * @return
     */
    public static List<SelectorIface> transformProcessorListInSelector(String payload) {
        List<SelectorIface> result = new ArrayList<SelectorIface>();
        StringTokenizer stProcessorTuple = new StringTokenizer(payload, ",");
        while (stProcessorTuple.hasMoreTokens()) {
            String processorTuple = stProcessorTuple.nextToken();
            StringTokenizer stProcessor = new StringTokenizer(processorTuple, "$");
            String processor[] = new String[]{"", ""};
            Integer index = 0;
            while (stProcessor.hasMoreTokens()) {
                processor[index++] = stProcessor.nextToken();
            }
            result.add(new Selector(processor[0], processor[1]));
        }
        return result;
    }
}