metron-streaming/Metron-DataLoads/src/main/java/org/apache/metron/dataloads/extractor/csv/CSVExtractor.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.metron.dataloads.extractor.csv;

import com.google.common.base.Splitter;
import com.google.common.collect.Iterables;
import com.opencsv.CSVParser;
import com.opencsv.CSVParserBuilder;
import org.apache.metron.dataloads.extractor.Extractor;
import org.apache.metron.threatintel.ThreatIntelResults;

import java.io.IOException;
import java.util.*;

public class CSVExtractor implements Extractor {
    public static final String COLUMNS_KEY="columns";
    public static final String INDICATOR_COLUMN_KEY="indicator_column";
    public static final String SEPARATOR_KEY="separator";

    private int indicatorColumn;
    private Map<String, Integer> columnMap = new HashMap<>();
    private CSVParser parser;

    @Override
    public Iterable<ThreatIntelResults> extract(String line) throws IOException {
        if(line.trim().startsWith("#")) {
            //comment
            return Collections.emptyList();
        }
        ThreatIntelResults ret = new ThreatIntelResults();
        String[] tokens = parser.parseLine(line);
        ret.getKey().indicator = tokens[indicatorColumn];
        for(Map.Entry<String, Integer> kv : columnMap.entrySet()) {
            ret.getValue().put(kv.getKey(), tokens[kv.getValue()]);
        }
        return Arrays.asList(ret);
    }

    private static Map.Entry<String, Integer> getColumnMapEntry(String column, int i) {
        if(column.contains(":")) {
            Iterable<String> tokens = Splitter.on(':').split(column);
            String col = Iterables.getFirst(tokens, null);
            Integer pos = Integer.parseInt(Iterables.getLast(tokens));
            return new AbstractMap.SimpleEntry<>(col, pos);
        }
        else {
            return new AbstractMap.SimpleEntry<>(column, i);
        }

    }
    private static Map<String, Integer> getColumnMap(Map<String, Object> config) {
        Map<String, Integer> columnMap = new HashMap<>();
        if(config.containsKey(COLUMNS_KEY)) {
            Object columnsObj = config.get(COLUMNS_KEY);
            if(columnsObj instanceof String) {
                String columns = (String)columnsObj;
                int i = 0;
                for (String column : Splitter.on(',').split(columns)) {
                    Map.Entry<String, Integer> e = getColumnMapEntry(column, i++);
                    columnMap.put(e.getKey(), e.getValue());
                }
            }
            else if(columnsObj instanceof List) {
                List columns = (List)columnsObj;
                int i = 0;
                for(Object column : columns) {
                    Map.Entry<String, Integer> e = getColumnMapEntry(column.toString(), i++);
                    columnMap.put(e.getKey(), e.getValue());
                }
            }
            else if(columnsObj instanceof Map) {
                Map<Object, Object> map = (Map<Object, Object>)columnsObj;
                for(Map.Entry<Object, Object> e : map.entrySet()) {
                    columnMap.put(e.getKey().toString(), Integer.parseInt(e.getValue().toString()));
                }
            }
        }
        return columnMap;
    }

    @Override
    public void initialize(Map<String, Object> config) {
        if(config.containsKey(COLUMNS_KEY)) {
            columnMap = getColumnMap(config);
        }
        else {
            throw new IllegalStateException("CSVExtractor requires " + COLUMNS_KEY + " configuration");
        }
        if(config.containsKey(INDICATOR_COLUMN_KEY)) {
            indicatorColumn = columnMap.get(config.get(INDICATOR_COLUMN_KEY).toString());
        }
        if(config.containsKey(SEPARATOR_KEY)) {
            char separator = config.get(SEPARATOR_KEY).toString().charAt(0);
            parser = new CSVParserBuilder().withSeparator(separator)
                                           .build();
        }
    }
}