[jira] [Updated] (TIKA-1437) encoding issue in AutoDetectReader

["Shuai Liu (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/TIKA-1437?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Shuai Liu updated TIKA-1437:
----------------------------
    Attachment: EncodingProblem.java

Encoding that reads a bunch of tsv files from a directory, and print out the encoding being produced by following tika encoding auto detection impl.
1) AutoDetectReader
2) UniversalEncodingDetector (producing same same as 1 as AutoDetectReader is calling UniversalEncodingDetector to get the encoding to read streams).
3) CharsetDetector (we are usng this detector to work around the current encoding issue)

> encoding issue in AutoDetectReader
> ----------------------------------
>
>                 Key: TIKA-1437
>                 URL: https://issues.apache.org/jira/browse/TIKA-1437
>             Project: Tika
>          Issue Type: Bug
>          Components: detector, parser
>    Affects Versions: 1.6
>         Environment: Windows 8
>            Reporter: Shuai Liu
>            Priority: Critical
>         Attachments: EncodingProblem.java
>
>
> We are having an encoding problem with Tika AutoDetectReader;
> we are using AutoDetectReader to read an stream to extract the string values by calling readLine()::AutoDetectReader. We find that the Encoding problem is happening in UniversalEncodingDetector being called by AutoDetectReader when reading the input stream being passed as one of the arguments in our TSVParser’s parse method. 
> We are using AutoDetectReader in our parser and we believed it was able auto detect an correct encoding from the input stream being passed to it, but we are seeing several garbled chars bubbling up in our outputted and converted files from our parser; we find out that the encoding problem is happening in the UniversalEncodingDetector, which returns an UTF-8 and AutoDetectReader is reading the stream with UTF-8 which is incorrect encoding; and the correct encoding is ISO-8859-1.
> I am attaching the screenshot of what I am talking about, the following is a raw tsv file; you can see the hex code E9 is presented as a char between M and xico, I believe it is a ‘e’ but in different encoding/language.
> The problem is that the AutoDetectReader is decoding and reading the chars with incorrect encoding. 
> BTW, We were able to work around this problem with CharsetDetector, which seems to generate a valid encoding for the moment with which we can use to read the tsv file properly.
> However, the problem is we cannot use AutoDetectReader, we have to create our own TSVAutoDetectReader incorporated with CharsetDetector in the detect method; AutoDetectReader class seems to be less flexible for us to extend its functions, many of its methods are restricted with private constraints, we cannot manually set encoding or override the existing implementation for detecting encoding.
> In addition, I am also not confident about CharsetDetector either; as I am seeing different encodings produced by CharsetDetector and AutoDetectReader for different tsv files; But for now, we might live with CharsetDetector, as CharsetDetector is solving the current encoding problem.
> Finally, I would like to please give you my test program (PFA: EncodingProblem.java) that reads an inputted tsv directory and displays a list of encodings for each of the tsv files in the directory produced by AutoDetectReader, UniversalEncodingDetector(which is being called by AutoDetectReader) and CharsetDetector; so you could probably see the difference, they are producing different encodings for some tsv files.



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