Description
Not sure what the implementation problem is but based on the API doc, there's a real flaw in XmlIO.Read:
By default, UTF-8 charset is used. To specify a different charset, use [XmlIO.Read.withCharset(java.nio.charset.Charset)|https://beam.apache.org/releases/javadoc/2.2.0/org/apache/beam/sdk/io/xml/XmlIO.Read.html#withCharset-java.nio.charset.Charset-].
Currently, only XML files that use single-byte characters are supported. Using a file that contains multi-byte characters may result in data loss or duplication.
Properly handled, there is never any need to specify the character encoding when reading an XML document. XML documents fully identify their character encoding. The developer at this level doesn't need to know and shouldn't think about the character encoding. Perhaps in the source code someone is a using a Reader where they should be using an InputStream instead? That might lead this problem.
Also, the text contradicts itself. UTF-8 is a multibyte character set. I hope that doesn't lead to data loss or duplication by default.
Imported from Jira BEAM-11875. Original Jira may contain additional context.
Reported by: elharo.