com.datascience.hadoop.CsvRecordReaderTest.java Source code

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Here is the source code for com.datascience.hadoop.CsvRecordReaderTest.java

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/*
 * Copyright 2015 the original author or authors.
 *
 * 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.datascience.hadoop;

import cascading.tap.TapException;
import com.datascience.util.CsvParseException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordReader;
import org.junit.Before;
import org.junit.Test;

import java.io.File;
import java.io.IOException;

import static org.junit.Assert.assertEquals;

/**
 * CSV record reader tests.
 *
 * @author amareeshbasanapalli
 */
public class CsvRecordReaderTest {

    Configuration conf;
    CsvHelper helper;
    JobConf jobConf;
    FileSystem fs;

    @Before
    public void initialize() throws IOException {
        helper = new CsvHelper();
        String[] columns = { "id", "first name", "last name" };
        conf = helper.buildConfiguration(",", "true", "\n", columns);
        jobConf = new JobConf(conf);
        fs = FileSystem.get(conf);
    }

    /**
     * Tests if RecordReader reads all records from regular input file.
     */
    @Test
    public void readerShouldReadAllRecords() throws IOException {
        testForReadAllRecords("/input/with-headers.txt", 3, 6);
    }

    /**
     * Tests if RecordReader reads all records from compressed input file.
     */
    @Test
    public void readerShouldReadAllRecordsFromCompressedFile() throws IOException {
        testForReadAllRecords("/input/with-headers.txt.gz", 3, 6);
    }

    @Test
    public void readingExtraColumnsWhenNotStrict() throws IOException {

        helper = new CsvHelper();
        String[] columns = { "id", "first name", "last name", "city", "zip" };
        conf = helper.buildConfiguration("\t", "true", "\n", columns);
        conf.setBoolean(CsvInputFormat.STRICT_MODE, false);
        jobConf = new JobConf(conf);
        fs = FileSystem.get(conf);
        testForReadAllRecordsNotStrict("/input/with-extra-columns.txt", 7);
    }

    @Test(expected = CsvParseException.class)
    public void readingExtraColumnsWhenStrict() throws IOException {

        helper = new CsvHelper();
        String[] columns = { "id", "first name", "last name", "city", "zip" };
        conf = helper.buildConfiguration("\t", "true", "\n", columns);
        conf.setBoolean(CsvInputFormat.STRICT_MODE, true);
        jobConf = new JobConf(conf);
        fs = FileSystem.get(conf);
        testForReadAllRecords("/input/with-extra-columns.txt", 5, 5);
    }

    @Test(expected = RuntimeException.class)
    public void readerShouldNotParseErrorRecords() throws IOException {
        conf.set(CsvInputFormat.CSV_READER_QUOTE_CHARACTER, "\"");

        jobConf = new JobConf(conf);
        fs = FileSystem.get(conf);

        testForReadAllRecords("/input/skipped-lines.txt", 3, 4);
    }

    /**
     * Helper function that iterates through Record Reader and assert record RecordCount and RecordLength.
     */
    public void testForReadAllRecords(String fileName, int expectedRowLength, int expectedRecordCount)
            throws IOException {
        CsvInputFormat inputFormat = helper.createCSVInputFormat(conf);
        File inputFile = helper.getFile(fileName);
        Path inputPath = new Path(inputFile.getAbsoluteFile().toURI().toString());
        FileSplit split = helper.createFileSplit(inputPath, 0, inputFile.length());

        RecordReader createdReader = helper.createRecordReader(inputFormat, split, jobConf);

        LongWritable key = new LongWritable();
        ListWritable<Text> value = new ListWritable<Text>(Text.class);

        int actualRecordCount = 0;

        while (createdReader.next(key, value)) {
            actualRecordCount++;
            assertEquals(expectedRowLength, value.size());
        }
        assertEquals(expectedRecordCount, actualRecordCount);
    }

    /**
     * Helper function that iterates through Recrord Reader and asserts RecrordCount
     */
    public void testForReadAllRecordsNotStrict(String fileName, int expectedRecordCount) throws IOException {
        CsvInputFormat inputFormat = helper.createCSVInputFormat(conf);
        File inputFile = helper.getFile(fileName);
        Path inputPath = new Path(inputFile.getAbsoluteFile().toURI().toString());
        FileSplit split = helper.createFileSplit(inputPath, 0, inputFile.length());

        RecordReader createdReader = helper.createRecordReader(inputFormat, split, jobConf);

        LongWritable key = new LongWritable();
        ListWritable<Text> value = new ListWritable<Text>(Text.class);

        int actualRecordCount = 0;

        while (createdReader.next(key, value)) {
            actualRecordCount++;
        }
        assertEquals(expectedRecordCount, actualRecordCount);
    }

}