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FastCSV is an ultra-fast and dependency-free [RFC 4180](https://tools.ietf.org/html/rfc4180) 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 & Compatibility
A selected benchmark from the
[Java CSV library benchmark suite](https://github.com/osiegmar/JavaCsvBenchmarkSuite) project:
While maintaining high performance, FastCSV is a strict RFC 4180 CSV writer but also able
to read garbled CSV data (to some degree). See [JavaCsvComparison](https://github.com/osiegmar/JavaCsvComparison) for details.
## 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 macOS) and LF (Unix)
- Unicode support
### Reader specific
- Support reading of some non-compliant (real world) data
- 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
- Support for writing comments with proper quotation if needed
## Requirements
- Java 8
> :bulb: 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
```java
CsvReader.builder().build("foo1,bar1\r\nfoo2,bar2")
.forEach(System.out::println);
```
Iterative reading of some CSV data with a header
```java
NamedCsvReader.builder().build("header 1,header 2\nfield 1,field 2")
.forEach(row -> row.getField("header 2"));
```
Iterative reading of a CSV file
```java
try (CsvReader csv = CsvReader.builder().build(path)) {
csv.forEach(System.out::println);
}
```
Custom settings
```java
CsvReader.builder()
.fieldSeparator(';')
.quoteCharacter('"')
.commentStrategy(CommentStrategy.SKIP)
.commentCharacter('#')
.skipEmptyRows(true)
.errorOnDifferentFieldCount(false);
```
For more example see
[CsvReaderExample.java](src/example/java/example/CsvReaderExample.java)
## CsvWriter Examples
Iterative writing of some data to a writer
```java
CsvWriter.builder().build(new PrintWriter(System.out, true))
.writeRow("header1", "header2")
.writeRow("value1", "value2");
```
Iterative writing of a CSV file
```java
try (CsvWriter csv = CsvWriter.builder().build(path)) {
csv
.writeRow("header1", "header2")
.writeRow("value1", "value2");
}
```
Custom settings
```java
CsvWriter.builder()
.fieldSeparator(',')
.quoteCharacter('"')
.quoteStrategy(QuoteStrategy.REQUIRED)
.lineDelimiter(LineDelimiter.LF);
```
For more example see
[CsvWriterExample.java](src/example/java/example/CsvWriterExample.java)
## Upgrading from version 1.x
Please see [UPGRADING.md](UPGRADING.md) for an overview of the main functionality of 1.x
and how to upgrade them to version 2.
---
## Sponsoring and partnerships
YourKit was used to optimize the performance and footprint of FastCSV.
YourKit is the creator of YourKit Java Profiler,
YourKit .NET Profiler,
and YourKit YouMonitor.
