CSV API for Java [closed]

Question

I've used OpenCSV in the past.

import au.com.bytecode.opencsv.CSVReader;

String fileName = "data.csv";
CSVReader reader = new CSVReader(new FileReader(fileName ));

// if the first line is the header
String[] header = reader.readNext();

// iterate over reader.readNext until it returns null
String[] line = reader.readNext();

There were some other choices in the answers to another question.

Apache Commons CSV

Check out Apache Common CSV.

This library reads and writes several variations of CSV, including the standard one RFC 4180. Also reads/writes Tab-delimited files.

• Excel
• InformixUnload
• InformixUnloadCsv
• MySQL
• Oracle
• PostgreSQLCsv
• PostgreSQLText
• RFC4180
• TDF

Update: The code in this answer is for Super CSV 1.52. Updated code examples for Super CSV 2.4.0 can be found at the project website: http://super-csv.github.io/super-csv/index.html

---

The SuperCSV project directly supports the parsing and structured manipulation of CSV cells. From http://super-csv.github.io/super-csv/examples_reading.html you'll find e.g.

given a class

public class UserBean {
    String username, password, street, town;
    int zip;

    public String getPassword() { return password; }
    public String getStreet() { return street; }
    public String getTown() { return town; }
    public String getUsername() { return username; }
    public int getZip() { return zip; }
    public void setPassword(String password) { this.password = password; }
    public void setStreet(String street) { this.street = street; }
    public void setTown(String town) { this.town = town; }
    public void setUsername(String username) { this.username = username; }
    public void setZip(int zip) { this.zip = zip; }
}

and that you have a CSV file with a header. Let's assume the following content

username, password,   date,        zip,  town
Klaus,    qwexyKiks,  17/1/2007,   1111, New York
Oufu,     bobilop,    10/10/2007,  4555, New York

You can then create an instance of the UserBean and populate it with values from the second line of the file with the following code

class ReadingObjects {
  public static void main(String[] args) throws Exception{
    ICsvBeanReader inFile = new CsvBeanReader(new FileReader("foo.csv"), CsvPreference.EXCEL_PREFERENCE);
    try {
      final String[] header = inFile.getCSVHeader(true);
      UserBean user;
      while( (user = inFile.read(UserBean.class, header, processors)) != null) {
        System.out.println(user.getZip());
      }
    } finally {
      inFile.close();
    }
  }
}

using the following "manipulation specification"

final CellProcessor[] processors = new CellProcessor[] {
    new Unique(new StrMinMax(5, 20)),
    new StrMinMax(8, 35),
    new ParseDate("dd/MM/yyyy"),
    new Optional(new ParseInt()),
    null
};

Reading CSV format description makes me feel that using 3rd party library would be less headache than writing it myself:

• http://en.wikipedia.org/wiki/Comma-separated_values

Wikipedia lists 10 or something known libraries:

• http://en.wikipedia.org/wiki/CSV_application_support

I compared libs listed using some kind of check list. OpenCSV turned out a winner to me (YMMV) with the following results:

+ maven

+ maven - release version   // had some cryptic issues at _Hudson_ with snapshot references => prefer to be on a safe side

+ code examples

+ open source   // as in "can hack myself if needed"

+ understandable javadoc   // as opposed to eg javadocs of _genjava gj-csv_

+ compact API   // YAGNI (note *flatpack* seems to have much richer API than OpenCSV)

- reference to specification used   // I really like it when people can explain what they're doing

- reference to _RFC 4180_ support   // would qualify as simplest form of specification to me

- releases changelog   // absence is quite a pity, given how simple it'd be to get with maven-changes-plugin   // _flatpack_, for comparison, has quite helpful changelog

+ bug tracking

+ active   // as in "can submit a bug and expect a fixed release soon"

+ positive feedback   // Recommended By 51 users at sourceforge (as of now)