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From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (TIKA-1369) Date parsing and thread safety in ImageMetadataExtractor
Date Tue, 29 Jul 2014 10:25:39 GMT

    [ https://issues.apache.org/jira/browse/TIKA-1369?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14077584#comment-14077584

ASF GitHub Bot commented on TIKA-1369:

GitHub user vilmospapp opened a pull request:


    TIKA-1369 Resolve thread safety issue in ImageMetadataExtractor 

    This fix tries to resolve TIKA-1369 with handle thread safety by ThreadLocal and avoid
other library dependencies.
    I have run the test cases, so it seems correct to me, though I haven't found any other
occurrence of ThreadLocal in Tika's source, so perhaps it's against your general patterns.

You can merge this pull request into a Git repository by running:

    $ git pull https://github.com/vilmospapp/tika TIKA-1369

Alternatively you can review and apply these changes as the patch at:


To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

    This closes #15
commit 3a9575fc56a6463b4378b14820e9079352bb1848
Author: Vilmos Papp <papp.gyorgy.vilmos@gmail.com>
Date:   2014-07-23T09:18:50Z

    TIKA-1369 Make SimpleDateFormat usage thread safe


> Date parsing and thread safety in ImageMetadataExtractor
> --------------------------------------------------------
>                 Key: TIKA-1369
>                 URL: https://issues.apache.org/jira/browse/TIKA-1369
>             Project: Tika
>          Issue Type: Bug
>          Components: parser
>    Affects Versions: 1.5
>         Environment: OS X 10.9.4 Java 7_60
>            Reporter: John Gibson
>            Priority: Critical
> The {{ImageMetadataExtractor}} uses a static instance of {{SimpleDateFormat}}.  This
is not thread safe.
> {code:title=ImageMetadataExtractor.java}
>     static class ExifHandler implements DirectoryHandler {
>         private static final SimpleDateFormat DATE_UNSPECIFIED_TZ = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
>         ...
>         public void handleDateTags(Directory directory, Metadata metadata)
>                 throws MetadataException {
>             // Date/Time Original overrides value from ExifDirectory.TAG_DATETIME
>             Date original = null;
>             if (directory.containsTag(ExifSubIFDDirectory.TAG_DATETIME_ORIGINAL)) {
>                 original = directory.getDate(ExifSubIFDDirectory.TAG_DATETIME_ORIGINAL);
>                 // Unless we have GPS time we don't know the time zone so date must be
>                 // as ISO 8601 datetime without timezone suffix (no Z or +/-)
>                 if (original != null) {
>                     String datetimeNoTimeZone = DATE_UNSPECIFIED_TZ.format(original);
// Same time zone as Metadata Extractor uses
>                     metadata.set(TikaCoreProperties.CREATED, datetimeNoTimeZone);
>                     metadata.set(Metadata.ORIGINAL_DATE, datetimeNoTimeZone);
>                 }
>             }
>        ...
> {code}
> This is not the first time that SDF has caused problems: TIKA-495, TIKA-864. In the discussion
there the idea of using alternative thread-safe (and faster) formatters from either Joda time
or Commons Lang were dismissed because they would add too many dependencies. Given that Tika
already has a fairly large laundry list of dependencies to parse content, adding one more
JAR to make sure things don't break is probably a good idea.
> In addition, because no timezone or locale are specified by either Tika's formatter or
the call to com.drew.metadata.Directory it can wreak havok during randomized testing. Given
that the timezone is unknown, why not just default it to UTC and let the caller guess the
timezone? As it stands I have to reparse all of the dates into UTC to get stable behavior
across timezones.

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