Saltar al contenido

La forma más rápida de leer un archivo CSV java

Solución:

tl; dr

Leer un archivo CSV de 20 MB y crear una instancia de un objeto por fila requiere menos de 1 segundo en tiempo total transcurrido.

Detalles

No definiste el término “lento”. Así que hice un experimento, una prueba de referencia informal.

Primero creamos un archivo de 20 MB de 40.000 Person registros. Cada Person contiene un nombre y apellido en francés, un UUID y algún texto arbitrario como descripción. Los datos se escriben como cuatro columnas en un archivo CSV en UTF-8. Usé el Apache Commons CSV biblioteca para escribir y leer.

En segundo lugar, se lee este archivo escrito. Cada fila de datos se lee en la memoria y luego se utiliza para crear una instancia y recopilar un Person objeto.

Leer este archivo y crear instancias Person objeto para cada fila tomó menos de un segundo en tiempo total transcurrido. Cada fila tarda unos 20.000 nanosegundos. En realidad, esto incluye leer el archivo. dos veces, ya que hacemos un escaneo para contar el número de filas de datos para establecer la capacidad inicial de las instancias recopiladas. Además, estamos analizando una entrada de cadena hexadecimal en el valor de 128 bits de un UUID, por lo que dedicamos algo de tiempo al procesamiento de datos (no solo a la lectura).

Aquí está el Person clase.

package work.basil.example;

import java.util.UUID;

public class Person
{
    // Static
   static public  String LOREM_IPSUM = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";

    // Member variables.
    public String givenName, surname, description;
    public UUID id;

    public Person ( String givenName , String surname , UUID id , String description)
    {
        this.givenName = givenName;
        this.surname = surname;
        this.id = id;
        this.description = description ;
    }

    @Override
    public String toString ()
    {
        return "Person{ " +
                "givenName="" + givenName + "'' +
                " | surname="" + surname + "'' +
                " | id='" + id + ''' +
                " }";
    }
}

Y aquí está la aplicación completa que escribe y luego lee el archivo de 20 MB. Por favor, estudie y critique, ya que preparé esto en un santiamén. No he verificado mi trabajo dos veces.

Encontraras un write método, y un read método. los main El método llama a ambos y realiza un seguimiento del tiempo.

package work.basil.example;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;
import org.apache.commons.csv.CSVRecord;

import java.io.BufferedReader;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.Duration;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.ThreadLocalRandom;

public class CsvSpeed
{
    public List < Person > read ( Path path )
    {
        // TODO: Add a check for valid file existing.

        List < Person > list = List.of();  // Default to empty list.
        try
        {
            // Prepare list.
            int initialCapacity = ( int ) Files.lines( path ).count();
            list = new ArrayList <>( initialCapacity );

            // Read CSV file. For each row, instantiate and collect `DailyProduct`.
            BufferedReader reader = Files.newBufferedReader( path );
            Iterable < CSVRecord > records = CSVFormat.RFC4180.withFirstRecordAsHeader().parse( reader );
            for ( CSVRecord record : records )
            {
                String givenName = record.get( "givenName" );
                String surname = record.get( "surname" );
                UUID id = UUID.fromString( record.get( "id" ) );
                String description = record.get( "description" );
                // Instantiate `Person` object, and collect it.
                Person person = new Person( givenName , surname , id , description );
                list.add( person );
            }
        } catch ( IOException e )
        {
            e.printStackTrace();
        }
        return list;
    }

    public void write ( final Path path )
    {
        ThreadLocalRandom random = ThreadLocalRandom.current();
        try ( final CSVPrinter printer = CSVFormat.RFC4180.withHeader( "givenName" , "surname" , "id" , "description" ).print( path , StandardCharsets.UTF_8 ) ; )
        {
            int limit = 40_000;  // 40_000 yields about 20 MB of data.
            List < String > givenNames = List.of( "Adrien" , "Aimon" , "Alerion" , "Alexis" , "Alezan" , "Ancil" , "Andre" , "Antoine" , "Archard" , "Aurélien" , "Averill" , "Baptiste" , "Barnard" , "Bartelemy" , "Bastien" , "Baylee" , "Beale" , "Beau" , "Beaumont" , "Beauregard" , "Bellamy" , "Berger" , "Blaize" , "Blondel" , "Boyce" , "Bruce" , "Brunelle" , "Brys" , "Burcet" , "Burnell" , "Burrell" , "Byron" , "Canaan" , "Carden" , "Carolas" , "Cavell" , "Chace" , "Chanler" , "Chante" , "Chappel" , "Charles" , "Chasen" , "Chason" , "Chemin" , "Chene" , "Cher" , "Chevalier" , "Cheyne" , "Clément" , "Clemence" , "Corbin" , "Coty" , "Cygne" , "Damien" , "Dandre" , "Dariel" , "Darl" , "Dauphine" , "Davet" , "Dax" , "Dean" , "Delice" , "Delmon" , "Destin" , "Dominique" , "Donatien" , "Duke" , "Eliott" , "Elroy" , "Enzo" , "Erwan" , "Etalon" , "Ethan" , "Fabron" , "Ferrand" , "Filberte" , "Florent" , "Florian" , "Fontaine" , "Forest" , "Fortune" , "Franchot" , "Francois" , "Fraser" , "Frayne" , "Gaëtan" , "Gabin" , "Gage" , "Gaige" , "Garland" , "Garner" , "Gaston" , "Gauge" , "Gaylord" , "Germain" , "Germaine" , "German" , "Gervaise" , "Giles" , "Gilles" , "Gitan" , "Grosvener" , "Guifford" , "Guion" , "Guy" , "Guzman" , "Henri" , "Holland" , "Hugo" , "Hugues" , "Hyacinthe" , "Jérémy" , "Jacquan" , "Jacques" , "Jacquez" , "Janvier" , "Jardan" , "Jay" , "Jaye" , "Jehan" , "Jemond" , "Jocquez" , "Jonathan" , "Jules" , "Julien" , "Justus" , "Karoly" , "Lado" , "Lafayette" , "Lamond" , "Lancelin" , "Landis" , "Landry" , "Laron" , "Larrimore" , "Laurent" , "LaValle" , "Leandre" , "Leggett" , "Leonce" , "Leron" , "Leverett" , "Lilian" , "Loïc" , "Lorenzo" , "Louis" , "Lowell" , "Luc" , "Lucien" , "Lukas" , "Macaire" , "Mace" , "Mahieu" , "Maison" , "Malleville" , "Manneville" , "Mantel" , "Marc" , "Marcel" , "Marion" , "Marius" , "Markez" , "Markis" , "Marmion" , "Marquis" , "Marquise" , "Marshall" , "Martial" , "Maslin" , "Mason" , "Matheo" , "Mathias" , "Mathys" , "Matthieu" , "Maxence" , "Mayson" , "Mehdi" , "Merle" , "Merville" , "Montague" , "Montaigu" , "Monte" , "Montgomery" , "Montreal" , "Montrel" , "Moore" , "Morel" , "Mortimer" , "Nerville" , "Neuveville" , "Nicolas" , "Noë" , "Noah" , "Noe" , "Norman" , "Norville" , "Nouel" , "Olivier" , "Onfroi" , "Paien" , "Parfait" , "Parnell" , "Pascal" , "Patrice" , "Paul" , "Peppin" , "Percival" , "Percy" , "Pernell" , "Peverell" , "Philipe" , "Pierpont" , "Pierre" , "Pomeroy" , "Prewitt" , "Purvis" , "Quennell" , "Quentin" , "Quincey" , "Quincy" , "Quintin" , "Rémi" , "Rafaelle" , "Ranger" , "Raoul" , "Raphaël" , "Rapier" , "Rawlins" , "Ray" , "Raynard" , "Remi" , "René" , "Renard" , "Rene" , "Reule" , "Reynard" , "Robin" , "Romain" , "Rondel" , "Roy" , "Royal" , "Ruff" , "Rush" , "Russel" , "Rustin" , "Sabastien" , "Sacha" , "Salomon" , "Samuel" , "Satordi" , "Saville" , "Scoville" , "Sebastien" , "Sennett" , "Severin" , "Shant" , "Shantae" , "Sidney" , "Siffre" , "Simeon" , "Simon" , "Sinclair" , "Sofiane" , "Somer" , "Stephane" , "Sully" , "Sydney" , "Sylvain" , "Talbot" , "Talon" , "Telford" , "Tempest" , "Teppo" , "Théo" , "Thayer" , "Thibault" , "Thibaut" , "Thiery" , "Tiennan" , "Tiennot" , "Titouan" , "Toussaint" , "Travaris" , "Tyson" , "Urson" , "Vachel" , "Valentin" , "Valere" , "Vallis" , "Verdun" , "Victoir" , "Victor" , "Waltier" , "William" , "Wyatt" , "Yanis" , "Yann" , "Yves" , "Yvon" , "Zosime" , "Abrial" , "Abrielle" , "Abril" , "Adele" , "Alair" , "Alerion" , "Amee" , "Angelique" , "Annette" , "Antonella" , "Arian" , "Ariane" , "Armandina" , "Aubree" , "Aubrielle" , "Audra" , "Avril" , "Bella" , "Berneta" , "Bette" , "Blaise" , "Blanche" , "Blasa" , "Bonte" , "Brie" , "Brienne" , "Brigit" , "Cachay" , "Calice" , "Camille" , "Camylle" , "Caprice" , "Caressa" , "Caroline" , "Catin" , "Celesta" , "Celeste" , "Cera" , "Cerise" , "Chablis" , "Chalice" , "Chambray" , "Champagne" , "Chandell" , "Chaney" , "Chantal" , "Chante" , "Chanterelle" , "Chantile" , "Chantilly" , "Chantrice" , "Charla" , "Charlotte" , "Charmane" , "Chaton" , "Chemin" , "Chenetta" , "Cher" , "Chere" , "Cheri" , "Cheryl" , "Christine" , "Cidney" , "Cinderella" , "Claire" , "Claudette" , "Colette" , "Cordelle" , "Cydnee" , "Daeja" , "Daija" , "Daja" , "Damzel" , "Darelle" , "Darlene" , "Darselle" , "Dejanelle" , "Deleena" , "Delice" , "Demeri" , "Deni" , "Denise" , "Desgracias" , "Desire" , "Desiree" , "Destanee" , "Destiny" , "Dior" , "Domanique" , "Dominique" , "Elaina" , "Elaine" , "Elayna" , "Elise" , "Eloisa" , "Elyse" , "Emeline" , "Emmaline" , "Emmeline" , "Estella" , "Estrella" , "Etiennette" , "Evette" , "Fabienne" , "Fabrienne" , "Fanchon" , "Fancy" , "Fawna" , "Fayana" , "Fayette" , "Fifi" , "Fleur" , "Fleurette" , "Fontanna" , "Fosette" , "Francine" , "Frederique" , "Gabriel" , "Gabriele" , "Gabrielle" , "Gaby" , "Garcelle" , "Gena" , "Genie" , "Georgette" , "Germaine" , "Gervaise" , "Gitana" , "Harriet" , "Heloisa" , "Holland" , "Honnetta" , "Isabelle" , "Ivette" , "Ivonne" , "Jacqueena" , "Jacquetta" , "Jacquiline" , "Jacyline" , "Jaime" , "Jakqueline" , "Janeen" , "Janelly" , "Janina" , "Janiqua" , "Janique" , "Jannnelle" , "Jaquita" , "Jardena" , "Jeanetta" , "Jermaine" , "Jessamine" , "Jewel" , "Jewell" , "Joli" , "Jolie" , "Josephine" , "Jozephine" , "Julieta" , "Karessa" , "Karmaine" , "Klara" , "Laine" , "Lanelle" , "Laramie" , "Layne" , "Layney" , "Leala" , "Leonette" , "Lissette" , "Lizette" , "Lourdes" , "Lucienne" , "Ly" , "Lyla" , "Lysette" , "Madelaine" , "Malerie" , "Manette" , "Marais" , "Marcelle" , "Marché" , "Mardi" , "Margo" , "Marguerite" , "Marie" , "Marie Claude" , "Marie Frances" , "Marie Joelle" , "Marie Pascale" , "Marie Sophie" , "Marjolaine" , "Marquise" , "Marvella" , "Mathieu" , "Matisse" , "Maurelle" , "Maurissa" , "Mavis" , "Melisande" , "Michelle" , "Miette" , "Mignon" , "Mimi" , "Mirya" , "Monet" , "Moniqua" , "Monteen" , "Musetta" , "Myrlie" , "Nadeen" , "Nadia" , "Nadiyah" , "Naeva" , "Nanon" , "Natalle" , "Naudia" , "Nettie" , "Nicholas" , "Nicki" , "Nicky" , "Nicole" , "Nicolette" , "Nicolina" , "Nicolle" , "Nikolette" , "Ninette" , "Ninon" , "Noelle" , "Nycole" , "Odelette" , "Opaline" , "Orane" , "Orva" , "Page" , "Parisa" , "Parnel" , "Parris" , "Patrice" , "Peridot" , "Pippi" , "Prairie" , "Rachele" , "Rachelle" , "Racquel" , "Raphaelle" , "Raquelle" , "Remi" , "Renée" , "Renea" , "Renelle" , "Renita" , "Risette" , "Rochelle" , "Romy" , "Rosabel" , "Rosiclara" , "Ruba" , "Russhell" , "Saleena" , "Salina" , "Satin" , "Sedona" , "Serene" , "Shandelle" , "Shanta" , "Shante" , "Shariah" , "Sharita" , "Sharleen" , "Sheree" , "Shereen" , "Sherell" , "Sherice" , "Sherry" , "Sidnee" , "Sidney" , "Sidnie" , "Sidonie" , "Sinclaire" , "Solange" , "Solen" , "Sorrel" , "Suzette" , "Sydnee" , "Sydney" , "Tallis" , "Tempest" , "Toinette" , "Turquoise" , "Veronique" , "Vignette" , "Villette" , "Violeta" , "Virginie" , "Voleta" , "Vonny" );
            List < String > surnames = List.of( "Arceneau" , "Aucoin" , "Babin" , "Babineaux" , "Benoit" , "Bergeron" , "Bernard" , "Bertrand" , "Bessette" , "Blanc" , "Blanchard" , "Bonnet" , "Boucher" , "Bourg" , "Bourque" , "Boutin" , "Bouvier" , "Braud" , "Broussard" , "Brun" , "Chevalier" , "David" , "Depaul" , "Desmarais" , "Disney" , "Dubois" , "Dupont" , "Dupuis" , "Durand" , "Fortescue" , "Fournier" , "Garnier" , "Gaudet" , "Gillet" , "Gillette" , "Girard" , "Gravois" , "Grosvenor" , "Lambert" , "Landry" , "Laroche" , "Laurent" , "Lefevre" , "Leroy" , "Leveque" , "Lisle" , "Martin" , "Michel" , "Molyneux" , "Moreau" , "Morel" , "Neville" , "Pelletier" , "Petit" , "Prideux" , "Renard" , "Richard" , "Robert" , "Rousseau" , "Roux" , "Rufus" , "Simon" , "Thomas" );
            for ( int i = 1 ; i <= limit ; i++ )
            {
                String givenName = givenNames.get( random.nextInt( 0 , givenNames.size() ) );
                String surname = surnames.get( random.nextInt( 0 , surnames.size() ) );
                UUID id = UUID.randomUUID();
                String description = Person.LOREM_IPSUM;
                printer.printRecord( givenName , surname , id , description );
            }
        } catch ( IOException e )
        {
            e.printStackTrace();
        }
    }

    public static void main ( final String[] args )
    {
        // Launch the app.
        CsvSpeed app = new CsvSpeed();

        // Write.
        String when = Instant.now().truncatedTo( ChronoUnit.SECONDS ).toString().replace( ":" , "•" );
        Path pathOutput = Paths.get( "/Users/basilbourque/persons.csv" );
        app.write( pathOutput );
        System.out.println( "Writing file: " + pathOutput );

        // Read.
        long start = System.nanoTime();
        Path pathInput = Paths.get( "/Users/basilbourque/persons.csv" );
        List < Person > list = app.read( pathInput );
        long stop = System.nanoTime();

        // Time.
        long elapsed = ( stop - start );
        Duration d = Duration.ofNanos( elapsed );
        System.out.println( "Reading elapsed: " + d );
        System.out.println( "Reading took nanos per row: " + ( elapsed / list.size() ) );
        System.out.println( "nanos elapsed: " + elapsed + "  |  list.size: " + list.size() );
    }
}

Cuando se ejecuta:

Archivo de escritura: /Users/basilbourque/persons.csv

Lectura transcurrida: PT0.857816234S

La lectura tomó nanos por fila: 21445

nanos transcurridos: 857816234 | lista.tamaño: 40000

Pila de tecnología:

  • Java 11.0.2 – zulú por Azul Systems (construido a partir de OpenJDK)
  • Ejecutar dentro de IntelliJ 2019.1
  • macOS Mojave
  • MacBook Pro (Retina, 15 pulgadas, finales de 2013)
  • Procesador: Intel Core i7 de 2,3 GHz (4 núcleos, 8 hiper)
  • DDR3 de 16 GB a 1600 MHz
  • Almacenamiento: estado sólido integrado por Apple

En csv-parsers-compare podemos encontrar una comparación entre CSV Reader/Writer-s. El mas rapido es uniVocity CSV parser. Tercero es Jackson que yo personalmente prefiero. Utilizando @Basil Bourque gran ejemplo lo cambié un poco y usé Jackson clases. El método leído devuelve MappingIterator que puede usar para inicializar su objeto de montón (vea cómo agregué elementos a List). No incluí detalles de tiempo, pero puede hacerlo usted mismo usando Basil’s y esta solución:

import com.fasterxml.jackson.databind.MappingIterator;
import com.fasterxml.jackson.databind.ObjectReader;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.fasterxml.jackson.dataformat.csv.CsvMapper;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;

import java.io.File;
import java.io.FileWriter;
import java.time.Duration;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.ThreadLocalRandom;

public class CsvSpeed {

    public static void main(String[] args) throws Exception {
        File csvFile = new File("./resource/persons.csv").getAbsoluteFile();

        CsvSchema schema = CsvSchema.builder()
                .addColumn("givenName")
                .addColumn("surname")
                .addColumn("id")
                .addColumn("description")
                .build().withHeader();

        CsvSpeed csvSpeed = new CsvSpeed();
        csvSpeed.write(csvFile, schema);

        // Read.
        long start = System.nanoTime();
        MappingIterator<Person> personMappingIterator = csvSpeed.read(csvFile, schema);
        List<Person> persons = new ArrayList<>(40_000);
        personMappingIterator.forEachRemaining(persons::add);

        long stop = System.nanoTime();

        System.out.println(persons.size());

        // Time.
        long elapsed = (stop - start);
        Duration d = Duration.ofNanos(elapsed);
        System.out.println("Reading elapsed: " + d);
        System.out.println("Reading took nanos per row: " + (elapsed / persons.size()));
        System.out.println("nanos elapsed: " + elapsed + "  |  list.size: " + persons.size());
    }

    public MappingIterator<Person> read(final File path, CsvSchema schema) throws Exception {
        CsvMapper csvMapper = new CsvMapper();

        ObjectReader reader = csvMapper.readerFor(Person.class).with(schema);
        return reader.readValues(path);
    }

    public void write(final File path, CsvSchema schema) throws Exception {
        ThreadLocalRandom random = ThreadLocalRandom.current();

        CsvMapper csvMapper = new CsvMapper();
        ObjectWriter writer = csvMapper.writerFor(Person.class).with(schema);

        try (FileWriter fileWriter = new FileWriter(path)) {
            List<String> givenNames = Arrays.asList("Adrien", "Aimon", "Alerion", "Alexis", "Alezan", "Ancil", "Andre", "Antoine", "Archard", "Aurélien", "Averill", "Baptiste", "Barnard", "Bartelemy", "Bastien", "Baylee", "Beale", "Beau", "Beaumont", "Beauregard", "Bellamy", "Berger", "Blaize", "Blondel", "Boyce", "Bruce", "Brunelle", "Brys", "Burcet", "Burnell", "Burrell", "Byron", "Canaan", "Carden", "Carolas", "Cavell", "Chace", "Chanler", "Chante", "Chappel", "Charles", "Chasen", "Chason", "Chemin", "Chene", "Cher", "Chevalier", "Cheyne", "Clément", "Clemence", "Corbin", "Coty", "Cygne", "Damien", "Dandre", "Dariel", "Darl", "Dauphine", "Davet", "Dax", "Dean", "Delice", "Delmon", "Destin", "Dominique", "Donatien", "Duke", "Eliott", "Elroy", "Enzo", "Erwan", "Etalon", "Ethan", "Fabron", "Ferrand", "Filberte", "Florent", "Florian", "Fontaine", "Forest", "Fortune", "Franchot", "Francois", "Fraser", "Frayne", "Gaëtan", "Gabin", "Gage", "Gaige", "Garland", "Garner", "Gaston", "Gauge", "Gaylord", "Germain", "Germaine", "German", "Gervaise", "Giles", "Gilles", "Gitan", "Grosvener", "Guifford", "Guion", "Guy", "Guzman", "Henri", "Holland", "Hugo", "Hugues", "Hyacinthe", "Jérémy", "Jacquan", "Jacques", "Jacquez", "Janvier", "Jardan", "Jay", "Jaye", "Jehan", "Jemond", "Jocquez", "Jonathan", "Jules", "Julien", "Justus", "Karoly", "Lado", "Lafayette", "Lamond", "Lancelin", "Landis", "Landry", "Laron", "Larrimore", "Laurent", "LaValle", "Leandre", "Leggett", "Leonce", "Leron", "Leverett", "Lilian", "Loïc", "Lorenzo", "Louis", "Lowell", "Luc", "Lucien", "Lukas", "Macaire", "Mace", "Mahieu", "Maison", "Malleville", "Manneville", "Mantel", "Marc", "Marcel", "Marion", "Marius", "Markez", "Markis", "Marmion", "Marquis", "Marquise", "Marshall", "Martial", "Maslin", "Mason", "Matheo", "Mathias", "Mathys", "Matthieu", "Maxence", "Mayson", "Mehdi", "Merle", "Merville", "Montague", "Montaigu", "Monte", "Montgomery", "Montreal", "Montrel", "Moore", "Morel", "Mortimer", "Nerville", "Neuveville", "Nicolas", "Noë", "Noah", "Noe", "Norman", "Norville", "Nouel", "Olivier", "Onfroi", "Paien", "Parfait", "Parnell", "Pascal", "Patrice", "Paul", "Peppin", "Percival", "Percy", "Pernell", "Peverell", "Philipe", "Pierpont", "Pierre", "Pomeroy", "Prewitt", "Purvis", "Quennell", "Quentin", "Quincey", "Quincy", "Quintin", "Rémi", "Rafaelle", "Ranger", "Raoul", "Raphaël", "Rapier", "Rawlins", "Ray", "Raynard", "Remi", "René", "Renard", "Rene", "Reule", "Reynard", "Robin", "Romain", "Rondel", "Roy", "Royal", "Ruff", "Rush", "Russel", "Rustin", "Sabastien", "Sacha", "Salomon", "Samuel", "Satordi", "Saville", "Scoville", "Sebastien", "Sennett", "Severin", "Shant", "Shantae", "Sidney", "Siffre", "Simeon", "Simon", "Sinclair", "Sofiane", "Somer", "Stephane", "Sully", "Sydney", "Sylvain", "Talbot", "Talon", "Telford", "Tempest", "Teppo", "Théo", "Thayer", "Thibault", "Thibaut", "Thiery", "Tiennan", "Tiennot", "Titouan", "Toussaint", "Travaris", "Tyson", "Urson", "Vachel", "Valentin", "Valere", "Vallis", "Verdun", "Victoir", "Victor", "Waltier", "William", "Wyatt", "Yanis", "Yann", "Yves", "Yvon", "Zosime", "Abrial", "Abrielle", "Abril", "Adele", "Alair", "Alerion", "Amee", "Angelique", "Annette", "Antonella", "Arian", "Ariane", "Armandina", "Aubree", "Aubrielle", "Audra", "Avril", "Bella", "Berneta", "Bette", "Blaise", "Blanche", "Blasa", "Bonte", "Brie", "Brienne", "Brigit", "Cachay", "Calice", "Camille", "Camylle", "Caprice", "Caressa", "Caroline", "Catin", "Celesta", "Celeste", "Cera", "Cerise", "Chablis", "Chalice", "Chambray", "Champagne", "Chandell", "Chaney", "Chantal", "Chante", "Chanterelle", "Chantile", "Chantilly", "Chantrice", "Charla", "Charlotte", "Charmane", "Chaton", "Chemin", "Chenetta", "Cher", "Chere", "Cheri", "Cheryl", "Christine", "Cidney", "Cinderella", "Claire", "Claudette", "Colette", "Cordelle", "Cydnee", "Daeja", "Daija", "Daja", "Damzel", "Darelle", "Darlene", "Darselle", "Dejanelle", "Deleena", "Delice", "Demeri", "Deni", "Denise", "Desgracias", "Desire", "Desiree", "Destanee", "Destiny", "Dior", "Domanique", "Dominique", "Elaina", "Elaine", "Elayna", "Elise", "Eloisa", "Elyse", "Emeline", "Emmaline", "Emmeline", "Estella", "Estrella", "Etiennette", "Evette", "Fabienne", "Fabrienne", "Fanchon", "Fancy", "Fawna", "Fayana", "Fayette", "Fifi", "Fleur", "Fleurette", "Fontanna", "Fosette", "Francine", "Frederique", "Gabriel", "Gabriele", "Gabrielle", "Gaby", "Garcelle", "Gena", "Genie", "Georgette", "Germaine", "Gervaise", "Gitana", "Harriet", "Heloisa", "Holland", "Honnetta", "Isabelle", "Ivette", "Ivonne", "Jacqueena", "Jacquetta", "Jacquiline", "Jacyline", "Jaime", "Jakqueline", "Janeen", "Janelly", "Janina", "Janiqua", "Janique", "Jannnelle", "Jaquita", "Jardena", "Jeanetta", "Jermaine", "Jessamine", "Jewel", "Jewell", "Joli", "Jolie", "Josephine", "Jozephine", "Julieta", "Karessa", "Karmaine", "Klara", "Laine", "Lanelle", "Laramie", "Layne", "Layney", "Leala", "Leonette", "Lissette", "Lizette", "Lourdes", "Lucienne", "Ly", "Lyla", "Lysette", "Madelaine", "Malerie", "Manette", "Marais", "Marcelle", "Marché", "Mardi", "Margo", "Marguerite", "Marie", "Marie Claude", "Marie Frances", "Marie Joelle", "Marie Pascale", "Marie Sophie", "Marjolaine", "Marquise", "Marvella", "Mathieu", "Matisse", "Maurelle", "Maurissa", "Mavis", "Melisande", "Michelle", "Miette", "Mignon", "Mimi", "Mirya", "Monet", "Moniqua", "Monteen", "Musetta", "Myrlie", "Nadeen", "Nadia", "Nadiyah", "Naeva", "Nanon", "Natalle", "Naudia", "Nettie", "Nicholas", "Nicki", "Nicky", "Nicole", "Nicolette", "Nicolina", "Nicolle", "Nikolette", "Ninette", "Ninon", "Noelle", "Nycole", "Odelette", "Opaline", "Orane", "Orva", "Page", "Parisa", "Parnel", "Parris", "Patrice", "Peridot", "Pippi", "Prairie", "Rachele", "Rachelle", "Racquel", "Raphaelle", "Raquelle", "Remi", "Renée", "Renea", "Renelle", "Renita", "Risette", "Rochelle", "Romy", "Rosabel", "Rosiclara", "Ruba", "Russhell", "Saleena", "Salina", "Satin", "Sedona", "Serene", "Shandelle", "Shanta", "Shante", "Shariah", "Sharita", "Sharleen", "Sheree", "Shereen", "Sherell", "Sherice", "Sherry", "Sidnee", "Sidney", "Sidnie", "Sidonie", "Sinclaire", "Solange", "Solen", "Sorrel", "Suzette", "Sydnee", "Sydney", "Tallis", "Tempest", "Toinette", "Turquoise", "Veronique", "Vignette", "Villette", "Violeta", "Virginie", "Voleta", "Vonny");
            List<String> surnames = Arrays.asList("Arceneau", "Aucoin", "Babin", "Babineaux", "Benoit", "Bergeron", "Bernard", "Bertrand", "Bessette", "Blanc", "Blanchard", "Bonnet", "Boucher", "Bourg", "Bourque", "Boutin", "Bouvier", "Braud", "Broussard", "Brun", "Chevalier", "David", "Depaul", "Desmarais", "Disney", "Dubois", "Dupont", "Dupuis", "Durand", "Fortescue", "Fournier", "Garnier", "Gaudet", "Gillet", "Gillette", "Girard", "Gravois", "Grosvenor", "Lambert", "Landry", "Laroche", "Laurent", "Lefevre", "Leroy", "Leveque", "Lisle", "Martin", "Michel", "Molyneux", "Moreau", "Morel", "Neville", "Pelletier", "Petit", "Prideux", "Renard", "Richard", "Robert", "Rousseau", "Roux", "Rufus", "Simon", "Thomas");
            Iterable<Person> persons = () -> {
                return new Iterator<Person>() {
                    int counter = 40_000; //0_000;  // 40_000 yields about 20 MB of data.

                    @Override
                    public boolean hasNext() {
                        return counter-- > 0;
                    }

                    @Override
                    public Person next() {
                        String givenName = givenNames.get(random.nextInt(0, givenNames.size()));
                        String surname = surnames.get(random.nextInt(0, surnames.size()));
                        UUID id = UUID.randomUUID();
                        String description = Person.LOREM_IPSUM;
                        return new Person(givenName, surname, id, description);
                    }
                };
            };
            writer.writeValues(fileWriter).writeAll(persons);
        }
    }
}

class Person {
    // Static
    static public String LOREM_IPSUM = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";

    // Member variables.
    private String givenName, surname, description;
    private UUID id;

    public Person() {

    }

    public Person(String givenName, String surname, UUID id, String description) {
        this.givenName = givenName;
        this.surname = surname;
        this.id = id;
        this.description = description;
    }

    public String getGivenName() {
        return givenName;
    }

    public void setGivenName(String givenName) {
        this.givenName = givenName;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public UUID getId() {
        return id;
    }

    public void setId(UUID id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "Person{ " +
                "givenName="" + givenName + "'' +
                " | surname="" + surname + "'' +
                " | id='" + id + ''' +
                " }";
    }
}

Además de usar java.nio como lo sugiere @Basil, simplemente envuelve el FileReader por un BufferedReader debería lograr una aceleración significativa.

FileReader fileReaderMes1 = new BufferedReader( new FileReader(FECHAS[0]));
¡Haz clic para puntuar esta entrada!
(Votos: 0 Promedio: 0)



Utiliza Nuestro Buscador

Deja una respuesta

Tu dirección de correo electrónico no será publicada. Los campos obligatorios están marcados con *