Parsing non-standard CSV with different Java CSV libraries

Unfortunately, there is no real industry standard for CSV files. The closest thing we do currently have (since 2005) is RFC 4180. Working with non-standardized data often comes with surprises, but what exactly happens when parsing CSV data that doesn't match this RFC?

This project is about to find that out...

This benchmark project was created for the development of FastCSV.

Note

Since this comparison uses the result of FastCSV as a reference value (expected result), the comparison is highly biased.

Implementations under test

Commons CSV 1.10.0
CSVeed 0.7.5
FastCSV 3.0.0
Jackson CSV 2.16.1
Java CSV 2.0
Opencsv 5.9
sesseltjonna-csv 1.0.25
SimpleFlatMapper 8.2.3
Super CSV 2.4.0
Univocity 2.9.1

Execute

./gradlew run

Results

To have results which are unambiguous to compare (even with multi-line records), we need to use some special characters. The libraries itself don't get in touch with these special characters as the conversion is done from the outside.

Character	Usage
`␣`	Space
`␍`	Carriage return
`␊`	Line feed
`[SE]`	Skip emtpy rows
`⏎`	New row
`↷`	New column
`◯`	Empty field
`∅`	Empty list

Unexpected results in Commons CSV

Input	Flags	Commons CSV	Expected	Implemented as expected by
`A,"B`	—	💥 UncheckedIOException	`A↷B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"A,B`	—	💥 UncheckedIOException	`A,B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"D"␣`	—	`D`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B`	`A,B␣`	FastCSV, SuperCSV
`"D"z`	—	💥 UncheckedIOException	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	💥 UncheckedIOException	`A,Bz`	FastCSV, SuperCSV

Unexpected results in CSVeed

Input	Flags	CSVeed	Expected	Implemented as expected by
`␣`	—	`◯`	`␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`␣,␣`	—	`◯↷◯`	`␣↷␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`,␣`	—	`◯↷◯`	`◯↷␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`␣D`	—	`D`	`␣D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`␣D␣,␣D␣`	—	`D↷D`	`␣D␣↷␣D␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`A,␊B`	—	💥 CsvException	`A↷◯⏎B`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`␣,`	—	`◯↷◯`	`␣↷◯`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`␣,␊D`	—	💥 CsvException	`␣↷◯⏎D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`D␊`	—	`D⏎◯`	`D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV, Univocity
`D␍`	—	`D⏎◯`	`D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV
`D␍␊`	—	`D⏎◯`	`D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV
`A,"B`	—	💥 CsvException	`A↷B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`A,B"`	—	💥 CsvException	`A↷B"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A,B`	—	💥 CsvException	`A,B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"A␍␊B"`	—	`A␍B`	`A␍␊B`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`A␊B,C`	—	💥 CsvException	`A⏎B↷C`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`A,B␊C`	—	💥 CsvException	`A↷B⏎C`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`A␊;B,C␊D`	—	💥 CsvException	`A⏎;B↷C⏎D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`"D"␣`	—	`D`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B`	`A,B␣`	FastCSV, SuperCSV
`␣"D"`	—	`D`	`␣"D"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`␣"D"␣`	—	`D`	`␣"D"␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"D"z`	—	💥 CsvException	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	💥 CsvException	`A,Bz`	FastCSV, SuperCSV
`z"D"`	—	💥 CsvException	`z"D"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"A,B"`	—	💥 CsvException	`z"A↷B"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"D"z`	—	💥 CsvException	`z"D"z`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity

Unexpected results in JacksonCSV

Input	Flags	JacksonCSV	Expected	Implemented as expected by
`A,"B`	—	💥 RuntimeJsonMappingException	`A↷B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"A,B`	—	💥 RuntimeJsonMappingException	`A,B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"D"␣`	—	`D`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B`	`A,B␣`	FastCSV, SuperCSV
`"D"z`	—	💥 RuntimeJsonMappingException	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	💥 RuntimeJsonMappingException	`A,Bz`	FastCSV, SuperCSV

Unexpected results in JavaCSV

Input	Flags	JavaCSV	Expected	Implemented as expected by
`"D"␣`	—	`D`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B`	`A,B␣`	FastCSV, SuperCSV
`"D"z`	—	`D`	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	`A,B`	`A,Bz`	FastCSV, SuperCSV

Unexpected results in Opencsv

Input	Flags	Opencsv	Expected	Implemented as expected by
`A,"B`	—	💥 CsvMalformedLineException	`A↷B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`A,B"`	—	💥 CsvMalformedLineException	`A↷B"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A,B`	—	💥 CsvMalformedLineException	`A,B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"A␍B"`	—	`A␊B`	`A␍B`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A␍␊B"`	—	`A␊B`	`A␍␊B`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A,B"␣`	—	`A,B"␣`	`A,B␣`	FastCSV, SuperCSV
`␣"D"`	—	`␣D`	`␣"D"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`␣"D"␣`	—	`␣D"␣`	`␣"D"␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A,B"z`	—	`A,B"z`	`A,Bz`	FastCSV, SuperCSV
`z"D"`	—	`zD`	`z"D"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"A,B"`	—	`zA,B`	`z"A↷B"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"D"z`	—	`zD"z`	`z"D"z`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity

Unexpected results in sesseltjonna-csv

Input	Flags	sesseltjonna-csv	Expected	Implemented as expected by
`A,␊B`	—	💥 CsvException	`A↷◯⏎B`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`␣,␊D`	—	💥 CsvException	`␣↷◯⏎D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`A␍B`	—	`A␍B`	`A⏎B`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV
`␍D`	—	`␍D`	`◯⏎D`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV
`A,"B`	—	💥 CsvBuilderException	`A↷B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"A,B`	—	💥 CsvBuilderException	`A,B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`A␊B,C`	—	`A⏎B,C`	`A⏎B↷C`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`A,B␊C`	—	💥 CsvException	`A↷B⏎C`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`A␊;B,C␊D`	—	`A⏎;B,C⏎D`	`A⏎;B↷C⏎D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV, Univocity
`"D"␣`	—	`D`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B`	`A,B␣`	FastCSV, SuperCSV
`"D"z`	—	`D`	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	`A,B`	`A,Bz`	FastCSV, SuperCSV

Unexpected results in Simpleflatmapper

Input	Flags	Simpleflatmapper	Expected	Implemented as expected by
`"D"␣`	—	`D"␣`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B"␣`	`A,B␣`	FastCSV, SuperCSV
`"D"z`	—	`D"z`	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	`A,B"z`	`A,Bz`	FastCSV, SuperCSV

Unexpected results in SuperCSV

Input	Flags	SuperCSV	Expected	Implemented as expected by
`A,"B`	—	💥 SuperCsvException	`A↷B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`A,B"`	—	💥 SuperCsvException	`A↷B"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A,B`	—	💥 SuperCsvException	`A,B`	FastCSV, JavaCSV, Simpleflatmapper, Univocity
`"A␍B"`	—	`A␊B`	`A␍B`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`"A␍␊B"`	—	`A␊B`	`A␍␊B`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`␣"D"`	—	`␣D`	`␣"D"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`␣"D"␣`	—	`␣D␣`	`␣"D"␣`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"D"`	—	`zD`	`z"D"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"A,B"`	—	`zA,B`	`z"A↷B"`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity
`z"D"z`	—	`zDz`	`z"D"z`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, sesseltjonna-csv, Simpleflatmapper, Univocity

Unexpected results in Univocity

Input	Flags	Univocity	Expected	Implemented as expected by
`A␍B`	—	`A␍B`	`A⏎B`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV
`D␍`	—	`D␍`	`D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV
`␍D`	—	`␍D`	`◯⏎D`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, Opencsv, Simpleflatmapper, SuperCSV
`␍D`	`[SE]`	`␍D`	`D`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, SuperCSV
`A␍␊B`	—	`A␍⏎B`	`A⏎B`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV
`D␍␊`	—	`D␍`	`D`	Commons CSV, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV
`␍␊D`	—	`␍⏎D`	`◯⏎D`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, Opencsv, sesseltjonna-csv, Simpleflatmapper, SuperCSV
`␍␊D`	`[SE]`	`␍⏎D`	`D`	Commons CSV, CSVeed, FastCSV, JacksonCSV, JavaCSV, SuperCSV
`"D"␣`	—	`D`	`D␣`	FastCSV, Opencsv, SuperCSV
`"A,B"␣`	—	`A,B`	`A,B␣`	FastCSV, SuperCSV
`"D"z`	—	`"D"z`	`Dz`	FastCSV, Opencsv, SuperCSV
`"A,B"z`	—	`"A,B"z`	`A,Bz`	FastCSV, SuperCSV

Big picture

Input	Flags	Expected	Commons CSV	CSVeed	FastCSV	JacksonCSV	JavaCSV	Opencsv	sesseltjonna-csv	Simpleflatmapper	SuperCSV	Univocity
`D`	—	`D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`D,D`	—	`D↷D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`,D`	—	`◯↷D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`␣`	—	`␣`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`␣,␣`	—	`␣↷␣`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`,␣`	—	`◯↷␣`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`␣D`	—	`␣D`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`␣D␣,␣D␣`	—	`␣D␣↷␣D␣`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`D,`	—	`D↷◯`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`A,␊B`	—	`A↷◯⏎B`	✅	💥	✅	✅	✅	✅	💥	✅	✅	✅
`␣,`	—	`␣↷◯`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`␣,␊D`	—	`␣↷◯⏎D`	✅	💥	✅	✅	✅	✅	💥	✅	✅	✅
`A␊B`	—	`A⏎B`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`D␊`	—	`D`	✅	❌	✅	✅	✅	✅	✅	✅	✅	✅
`␊D`	—	`◯⏎D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`␊D`	`[SE]`	`D`	✅	✅	✅	✅	✅	➖	➖	➖	✅	✅
`A␍B`	—	`A⏎B`	✅	✅	✅	✅	✅	✅	❌	✅	✅	❌
`D␍`	—	`D`	✅	❌	✅	✅	✅	✅	✅	✅	✅	❌
`␍D`	—	`◯⏎D`	✅	✅	✅	✅	✅	✅	❌	✅	✅	❌
`␍D`	`[SE]`	`D`	✅	✅	✅	✅	✅	➖	➖	➖	✅	❌
`A␍␊B`	—	`A⏎B`	✅	✅	✅	✅	✅	✅	✅	✅	✅	❌
`D␍␊`	—	`D`	✅	❌	✅	✅	✅	✅	✅	✅	✅	❌
`␍␊D`	—	`◯⏎D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	❌
`␍␊D`	`[SE]`	`D`	✅	✅	✅	✅	✅	➖	➖	➖	✅	❌
`"␣D␣"`	—	`␣D␣`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`"D"`	—	`D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`"D",D`	—	`D↷D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`D,"D"`	—	`D↷D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`A,"B`	—	`A↷B`	💥	💥	✅	💥	✅	💥	💥	✅	💥	✅
`A,B"`	—	`A↷B"`	✅	💥	✅	✅	✅	💥	✅	✅	💥	✅
`"A,B`	—	`A,B`	💥	💥	✅	💥	✅	💥	💥	✅	💥	✅
`"""D"`	—	`"D`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`"D"""`	—	`D"`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`"A""B"`	—	`A"B`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`"A␊B"`	—	`A␊B`	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
`"A␍B"`	—	`A␍B`	✅	✅	✅	✅	✅	❌	✅	✅	❌	✅
`"A␍␊B"`	—	`A␍␊B`	✅	❌	✅	✅	✅	❌	✅	✅	❌	✅
`A␊B,C`	—	`A⏎B↷C`	✅	💥	✅	✅	✅	✅	❌	✅	✅	✅
`A,B␊C`	—	`A↷B⏎C`	✅	💥	✅	✅	✅	✅	💥	✅	✅	✅
`A␊;B,C␊D`	—	`A⏎;B↷C⏎D`	✅	💥	✅	✅	✅	✅	❌	✅	✅	✅
`"D"␣`	—	`D␣`	❌	❌	✅	❌	❌	✅	❌	❌	✅	❌
`"A,B"␣`	—	`A,B␣`	❌	❌	✅	❌	❌	❌	❌	❌	✅	❌
`␣"D"`	—	`␣"D"`	✅	❌	✅	✅	✅	❌	✅	✅	❌	✅
`␣"D"␣`	—	`␣"D"␣`	✅	❌	✅	✅	✅	❌	✅	✅	❌	✅
`"D"z`	—	`Dz`	💥	💥	✅	💥	❌	✅	❌	❌	✅	❌
`"A,B"z`	—	`A,Bz`	💥	💥	✅	💥	❌	❌	❌	❌	✅	❌
`z"D"`	—	`z"D"`	✅	💥	✅	✅	✅	❌	✅	✅	❌	✅
`z"A,B"`	—	`z"A↷B"`	✅	💥	✅	✅	✅	❌	✅	✅	❌	✅
`z"D"z`	—	`z"D"z`	✅	💥	✅	✅	✅	❌	✅	✅	❌	✅

osiegmar/JavaCsvComparison