https://github.com/gpakosz/unicodebominputstream

Doing things right, in the name of Sun / Oracle
https://github.com/gpakosz/unicodebominputstream

bom inputstream java jdk unicode utf-8

Last synced: 2 days ago
JSON representation

Doing things right, in the name of Sun / Oracle

• Host: GitHub
• URL: https://github.com/gpakosz/unicodebominputstream
• Owner: gpakosz
• License: other
• Created: 2014-12-21T11:09:05.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2023-05-24T14:15:09.000Z (over 1 year ago)
• Last Synced: 2024-09-25T01:41:52.053Z (2 days ago)
• Topics: bom, inputstream, java, jdk, unicode, utf-8
• Language: Java
• Homepage:
• Size: 11.7 KB
• Stars: 37
• Watchers: 6
• Forks: 12
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Funding: .github/funding.yml
  • License: LICENSE

Awesome Lists containing this project

README

        
# UnicodeBOMInputStream

A helper class to skip [Unicode BOMs] at the beginning of input streams.

I initially released this class as a [Stack Overflow answer] and it apparently

got copy-pasted into several Java projects already. However, code put as answers

on Stack Overflow is licensed under [CC-BY-SA 3.0] which may not suit everybody.

[Unicode BOMs]: http://www.unicode.org/faq/utf_bom.html#bom1

[Stack Overflow answer]: http://stackoverflow.com/a/1835529/216063

--------------------------------------------------------------------------------

## Why?

Many years have passed since I wrote this class and today Java still doesn't

properly deal with UTF-8 Unicode Byte Order Marks (BOMs) at the beginning of

data.

In 2001, someone opened bug [JDK-4508058] with the sound expectation that Java

should detect and skip UTF-8 BOMs at the beginning of UTF-8 streams, the same

way it does for e.g. UTF-16.

Bug [JDK-4508058] remained open for a while, got fixed, and ultimately got

reverted because existing Java code relied on UTF-8 BOMs not being skipped, see

[JDK-6378911]:

> the Java EE 5 RI and SJSAS 9.0 has been relying on detecting a BOM, setting

> the appropriate encoding, and discarding the BOM bytes before reading the

> input

> The problem is that we cannot implement different behaviour depending on the

> JRE version we're running against.

In the end, instead of fixing [JDK-4508058] and accept this would be an

annoyance only for Java EE 5 RI and SJSAS 9.0 users, people in charge at Sun

couldn't be bothered supporting 2 JDK versions and decided we're all living in a

better world if [JDK-4508058] gets closed as "won't fix".

In 2010, someone opened bug [JDK-6959785] to reconsider the decision...

For more than 20 years now, every now and then, someone in the world edits an

XML file with `Notepad.exe` which adds useless UTF-8 BOMs, and breaks their

favorite Java XML parser.

Meanwhile, just skip the BOM yourself.

[JDK-4508058]: https://bugs.java.com/bugdatabase/view_bug?bug_id=4508058

[JDK-6378911]: https://bugs.java.com/bugdatabase/view_bug?bug_id=6378911

[JDK-6959785]: https://bugs.java.com/bugdatabase/view_bug?bug_id=6959785

[CC-BY-SA 3.0]: http://creativecommons.org/licenses/by-sa/3.0/legalcode

--------------------------------------------------------------------------------

## Usage

Wrap any `InputStream` with `UnicodeBOMInputStream` and use the `getBOM()`

and/or `skipBOM()` methods. See [`UnicodeBOMInputStreamUsage.java`].

[`UnicodeBOMInputStreamUsage.java`]: example/net/pempek/unicode/UnicodeBOMInputStreamUsage.java

--------------------------------------------------------------------------------

If you find this library useful and decide to use it in your own projects please

drop me a line [@gpakosz].

[@gpakosz]: https://twitter.com/gpakosz