elastic/elasticsearch

Use charset from Content-Type header

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#22769 opened on Jan 24, 2017

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Description

In https://github.com/elastic/elasticsearch/pull/22691#discussion_r96935452, I added a comment which points out that our code currently ignores the charset parameter of the Content-Type header and that this is something we should look into. Looking at the javadocs of JsonFactory to see how different charsets are handled:

Encoding is auto-detected from contents according to JSON
specification recommended mechanism. Json specification
supports only UTF-8, UTF-16 and UTF-32 as valid encodings,
so auto-detection implemented only for this charsets.
For other charsets use {@link #createParser(java.io.Reader)}.

Unfortunately not all clients adhere to the unicode only encodings as I have seen some send data as ISO-8859-1. I think we should consider parsing the charset from the content-type when available and handling appropriately (failing if we cannot support, convert, create parser differently etc.).

Contributor guide

Tech stack
javarest api
Domain
backendapi
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaHTTP Content TypeJSON parsing
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35
Research direction
Investigate the current handling of Content Type header in the REST layer, specifically where the charset is ignored. Refer to the comment in PR #22691 for context. Study the Jackson JsonFactory javadoc to understand supported encodings. Implement parsing of the charset parameter from the Content Type header and handle appropriately (e.g., fail if unsupported, or use a Reader for non unicode charsets). Ensure compatibility with the existing codebase.