com.metamx.common.parsers.ParserUtils Maven / Gradle / Ivy

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/*
 * Copyright 2011,2012 Metamarkets Group Inc.
 *
 * Licensed 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 com.metamx.common.parsers;

import com.google.common.base.Function;
import com.google.common.collect.Sets;
import com.metamx.common.IAE;
import org.joda.time.DateTime;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Set;

public class ParserUtils
{
  public static final Function nullEmptyStringFunction = new Function()
  {
    @Override
    public String apply(String input)
    {
      if (input == null || input.isEmpty()) {
        return null;
      }
      return input;
    }
  };

  public static ArrayList generateFieldNames(int length)
  {
    ArrayList names = new ArrayList<>(length);
    for (int i = 0; i < length; ++i) {
      names.add("column_" + (i + 1));
    }
    return names;
  }

  /**
   * Factored timestamp parsing into its own Parser class, but leaving this here
   * for compatibility
   *
   * @param format
   *
   * @return
   */
  public static Function createTimestampParser(final String format)
  {
    return TimestampParser.createTimestampParser(format);
  }

  public static Set findDuplicates(Iterable fieldNames)
  {
    Set duplicates = Sets.newHashSet();
    Set uniqueNames = Sets.newHashSet();

    for (String fieldName : fieldNames) {
      String next = fieldName.toLowerCase();
      if (uniqueNames.contains(next)) {
        duplicates.add(next);
      }
      uniqueNames.add(next);
    }

    return duplicates;
  }

  public static void validateFields(Iterable fieldNames)
  {
    Set duplicates = findDuplicates(fieldNames);
    if (!duplicates.isEmpty()) {
      throw new ParseException("Duplicate column entries found : %s", duplicates.toString());
    }
  }

  public static String stripQuotes(String input)
  {
    input = input.trim();
    if (input.charAt(0) == '\"' && input.charAt(input.length() - 1) == '\"') {
      input = input.substring(1, input.length() - 1).trim();
    }
    return input;
  }
}