com.metamx.common.parsers.ParserUtils.java Source code

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Here is the source code for com.metamx.common.parsers.ParserUtils.java

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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<String, String> nullEmptyStringFunction = new Function<String, String>() {
        @Override
        public String apply(String input) {
            if (input == null || input.isEmpty()) {
                return null;
            }
            return input;
        }
    };

    public static ArrayList<String> generateFieldNames(int length) {
        ArrayList<String> 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<String, DateTime> createTimestampParser(final String format) {
        return TimestampParser.createTimestampParser(format);
    }

    public static Set<String> findDuplicates(Iterable<String> fieldNames) {
        Set<String> duplicates = Sets.newHashSet();
        Set<String> 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<String> fieldNames) {
        Set<String> 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;
    }
}