[jira] [Updated] (NUTCH-2599) charset detection issue with parse-tika

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[jira] [Updated] (NUTCH-2599) charset detection issue with parse-tika

Jorge Spinsanti (Jira)

     [ https://issues.apache.org/jira/browse/NUTCH-2599?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Sebastian Nagel updated NUTCH-2599:
-----------------------------------
    Fix Version/s: 1.17

> charset detection issue with parse-tika
> ---------------------------------------
>
>                 Key: NUTCH-2599
>                 URL: https://issues.apache.org/jira/browse/NUTCH-2599
>             Project: Nutch
>          Issue Type: Bug
>          Components: parser
>         Environment: {code:java}
> plugin.includes: protocol-http|parse-tika{code}
>            Reporter: Gerard Bouchar
>            Priority: Major
>             Fix For: 1.17
>
>
> Here is an example page that is displayed correctly in web browsers, but is decoded with the wrong charset in nutch : [https://gerardbouchar.github.io/html-encoding-example/index.html]
>  
> This page's contents are encoded in UTF-8, it is served with HTTP headers indicating that it is in UTF-8, but it contains a bogus HTML meta tag indicating that is encoded in ISO-8859-1.
>  
> This is a tricky case, but there is a [W3C specification about how to handle it|https://html.spec.whatwg.org/multipage/parsing.html#determining-the-character-encoding]. It clearly states that the HTTP header (transport layer information) should have precedence over the HTML meta tag (obtained in [byte stream prescanning|https://html.spec.whatwg.org/multipage/parsing.html#prescan-a-byte-stream-to-determine-its-encoding]). Browsers do respect the spec, but the tika parser doesn't.
>  
> Looking at [the source code|https://github.com/apache/nutch/blob/master/src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/TikaParser.java], it looks like the charset information is not even extracted from the HTTP headers.
>  
> {code:java}
> HTTP/1.1 200 OK
> Content-Type: text/html; charset=utf-8
> <!doctype html>
> <html>
>   <head>
>     <meta charset="iso-8859-1">
>   </head>
>   <body>
>     <a href="/">français</a>
>   </body>
> </html>
> {code}



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