FastCSV

🚀 FastCSV 2.0 upgrade has landed with major improvements on performance and usability!

FastCSV is an ultra-fast and dependency-free RFC 4180 compliant CSV library for Java.

Actively developed and maintained since 2015 its primary intended use cases are:

big data applications to read and write data on a massive scale
small data applications with the need for a lightweight library

Benchmark

A selected benchmark from the Java CSV library benchmark suite project. Comparing to some other popular, dependency-free and small (< 100 KB) libraries.

Features

API

Ultra fast
Small footprint
Zero runtime dependencies
Null-free

CSV specific

RFC 4180 compliant – including:
- Newline and field separator characters in fields
- Quote escaping
Configurable field separator
Support for line endings CRLF (Windows), CR (old Mac OS) and LF (Unix)
Unicode support

Reader specific

Support reading of some non-compliant (real world) data (see comparison with other libraries)
Preserving line break character(s) within fields
Preserving the original line number (even with skipped and multi line records) – helpful for error messages
Auto detection of line delimiters (can also be mixed)
Configurable data validation
Support for (optional) header lines (get field based on column name)
Support for skipping empty rows
Support for commented lines (skipping & reading) and configurable comment character

Writer specific

Support for multiple quote strategies to differentiate between empty and null

Requirements

Java 8

💡 Android is not Java and is not officially supported. Although some basic checks are included in the continuous integration pipeline in order to verify that the library should work with Android 8.0 (API level 26).

CsvReader Examples

Iterative reading of some CSV data from a string

CsvReader.builder().build("foo1,bar1\r\nfoo2,bar2")
    .forEach(System.out::println);

Iterative reading of some CSV data with a header

NamedCsvReader.builder().build("header 1,header 2\nfield 1,field 2")
    .forEach(row -> row.getField("header 2"));

Iterative reading of a CSV file

try (CsvReader csv = CsvReader.builder().build(path, charset)) {
    csv.forEach(System.out::println);
}

Custom settings

CsvReader.builder()
    .fieldSeparator(';')
    .quoteCharacter('"')
    .commentStrategy(CommentStrategy.SKIP)
    .commentCharacter('#')
    .skipEmptyRows(true)
    .errorOnDifferentFieldCount(false);

For more example see CsvReaderExample.java

CsvWriter Examples

Iterative writing of some data to a writer

CsvWriter.builder().build(new PrintWriter(System.out, true))
    .writeRow("header1", "header2")
    .writeRow("value1", "value2");

Iterative writing of a CSV file

try (CsvWriter csv = CsvWriter.builder().build(path, charset)) {
    csv
        .writeRow("header1", "header2")
        .writeRow("value1", "value2");
}

Custom settings

CsvWriter.builder()
    .fieldSeparator(',')
    .quoteCharacter('"')
    .quoteStrategy(QuoteStrategy.REQUIRED)
    .lineDelimiter(LineDelimiter.LF);

For more example see CsvWriterExample.java

Upgrading from version 1.x

Please see UPGRADING.md for an overview of the main functionality of 1.x and how to upgrade them to version 2.

dagnelies / FastCSV