ch.cern.db.flume.interceptor.JSONEventToCSVInterceptor.java Source code

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Here is the source code for ch.cern.db.flume.interceptor.JSONEventToCSVInterceptor.java

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/**
 * Copyright (C) 2016, CERN
 * This software is distributed under the terms of the GNU General Public
 * Licence version 3 (GPL Version 3), copied verbatim in the file "LICENSE".
 * In applying this license, CERN does not waive the privileges and immunities
 * granted to it by virtue of its status as Intergovernmental Organization
 * or submit itself to any jurisdiction.
 */

package ch.cern.db.flume.interceptor;

import java.util.LinkedList;
import java.util.List;
import java.util.Map.Entry;

import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.event.EventBuilder;
import org.apache.flume.interceptor.Interceptor;

import ch.cern.db.flume.JSONEvent;

import com.google.gson.JsonElement;
import com.google.gson.JsonObject;

/**
 * 
 * 
 * @author daniellanzagarcia
 *
 */
public class JSONEventToCSVInterceptor implements Interceptor {

    private JSONEventToCSVInterceptor() {
    }

    @Override
    public void initialize() {
    }

    @Override
    public Event intercept(Event event) {
        if (!(event instanceof JSONEvent))
            return event;

        StringBuilder csv = new StringBuilder();

        JsonObject json = ((JSONEvent) event).getJsonObject();
        boolean first = true;
        for (Entry<String, JsonElement> property : json.entrySet()) {
            if (first)
                first = false;
            else
                csv.append(",");

            csv.append(property.getValue());
        }

        return EventBuilder.withBody(csv.toString().getBytes(), event.getHeaders());
    }

    @Override
    public List<Event> intercept(List<Event> events) {
        LinkedList<Event> intercepted = new LinkedList<Event>();

        for (Event event : events) {
            intercepted.add(intercept(event));
        }

        return intercepted;
    }

    @Override
    public void close() {
    }

    /**
     * Builder which builds new instance of this class
     */
    public static class Builder implements Interceptor.Builder {

        @Override
        public void configure(Context context) {
        }

        @Override
        public Interceptor build() {
            return new JSONEventToCSVInterceptor();
        }

    }

}