db-ddlutils-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Michael Lipp (JIRA)" <j...@apache.org>
Subject [jira] Updated: (DDLUTILS-196) Text data dumped incorrectly
Date Sun, 02 Mar 2008 16:28:50 GMT

     [ https://issues.apache.org/jira/browse/DDLUTILS-196?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Michael Lipp updated DDLUTILS-196:
----------------------------------

    Attachment: patch.txt

This patch is against 1.0.

Note that I have separated the decision if value can be written as an attribute from the decision
whether it requires uuencoding (the criteria are really different).


> Text data dumped incorrectly
> ----------------------------
>
>                 Key: DDLUTILS-196
>                 URL: https://issues.apache.org/jira/browse/DDLUTILS-196
>             Project: DdlUtils
>          Issue Type: Bug
>          Components: Core (No specific database)
>    Affects Versions: 1.0
>         Environment: Any
>            Reporter: Michael Lipp
>            Assignee: Thomas Dudziak
>         Attachments: patch.txt
>
>
> DdlUtils does not properly preserve content through a dump/restore cycle if the content
contains newlines.
> DdlUtils takes the following approach for dumping text content:
> (1) Write as value attribute, unless it cannot be written as such
> (2) Write as "plain" element content unless it cannot be written as such
> (3) Write as CDATA unless it cannot be written as such
> (4) Write uuencoded.
> Now when can a value not be written as attribute value? Easy: when there is no valid
representation that reads back the same value. And here is the problem. The XML recommendation
specifies something called "attribute value normalization" (http://www.w3.org/TR/xml/#AVNormalize).
Due to this, white space characters except space (#xD, #xA, #x9) in attribute values are not
read back in the same way as they are written.
> There are two ways to circumvent this: (a) write them as character references (e.g. &#xD;)
or (b) skip to method (2). Option (a) cannot be used here , because it is impossible to write
a "&" in an attribute value when you use XMLStreamWriter. The spec says: 'However the
writeCharacters method is required to escape & , < and >  For attribute values the
writeAttribute method will escape the above characters plus "' (http://java.sun.com/webservices/docs/1.5/api/javax/xml/stream/XMLStreamWriter.html).
You might expect that the XMLStreamWriter.writeAttribute should handle escaping of the whitespace
characters (#xD, #xA, #x9), but if you read the spec carefully it does not say so. Leaves
option (b).
> The attached patch fixes this problem.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message