org.apache.metron.common.csv.CSVConverter.java Source code

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Here is the source code for org.apache.metron.common.csv.CSVConverter.java

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/**
 * 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.common.csv;

import com.google.common.base.Splitter;
import com.google.common.collect.Iterables;
import com.opencsv.CSVParser;
import com.opencsv.CSVParserBuilder;

import java.io.IOException;
import java.io.Serializable;
import java.util.AbstractMap;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static org.apache.commons.lang3.StringUtils.isEmpty;

public class CSVConverter implements Serializable {
    public static final String COLUMNS_KEY = "columns";
    public static final String SEPARATOR_KEY = "separator";
    protected Map<String, Integer> columnMap = new HashMap<>();
    protected CSVParser parser;

    public Map<String, Integer> getColumnMap() {
        return columnMap;
    }

    public CSVParser getParser() {
        return parser;
    }

    public Map<String, String> toMap(String line) throws IOException {
        if (ignore(line)) {
            return null;
        }
        String[] tokens = parser.parseLine(line);
        Map<String, String> values = new HashMap<>();
        for (Map.Entry<String, Integer> kv : columnMap.entrySet()) {
            values.put(kv.getKey(), tokens[kv.getValue()]);
        }
        return values;
    }

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

        }
        parser = new CSVParserBuilder().withSeparator(separator).build();
    }

    protected boolean ignore(String line) {
        if (null == line) {
            return true;
        }
        String trimmedLine = line.trim();
        return trimmedLine.startsWith("#") || isEmpty(trimmedLine);
    }

    public 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);
        }

    }

    public 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;
    }
}