StringHttpMessageConverter should assume charset UTF-8 for application/json [SPR-17568]

[spring-projects-issues]

Thomas Meyer opened SPR-17568 and commented

When using "@RequestBody String jsonString" for an @Controller's @RequestMapping and the body is send as application/json with UTF-8 encoding, Spring uses StringHttpMessageConverter to convert the message, as the content-type will be application/json without any explicit encoding, so the StringHttpMessageConverter will fall back to the default encoding ISO-8859-1 which may is in accordance with the HTTP spec but not with RFC7159, which says: "The default encoding is UTF-8" (chapter 8.1)

 

So the suggestion would be to add an exception in the StringHttpMessageConverter to use UTF-8 charset for application/json.

 

 

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Affects: 5.1.3

Referenced from: commits 05d6162

[spring-projects-issues]

Thomas Meyer commented

When using Jersey as client it's especially problematic as Jersey's StringMessageProvider (https://github.com/jersey/jersey/blob/master/core-common/src/main/java/org/glassfish/jersey/message/internal/StringMessageProvider.java ) uses default encoding UTF-8 for content-type application/json.

[spring-projects-issues]

Rossen Stoyanchev commented

This is also supported by the current HTTP 1.1 spec RFC 7231:

The default charset of ISO-8859-1 for text media types has been
removed; the default is now whatever the media type definition says.

We can update StringHttpMessageConverter to check for application/*+json and use UTF-8, which is what AbstractJackson2HttpMessageConverter does by default.