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https://issues.apache.org/jira/browse/OPENNLP-1520?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17794122#comment-17794122
]
Richard Zowalla edited comment on OPENNLP-1520 at 12/7/23 10:43 AM:
--------------------------------------------------------------------
For finish, this exception can only happen for the following Among elements
contained in a_6 (as method name is set)
{code:java}
new Among ( "den", 11, -1, "r_VI", methodObject )
new Among ( "seen", 11, -1, "r_LONG", methodObject )
new Among ( "tten", 11, -1, "r_VI", methodObject ){code}
It can be reproduced by
{code:java}
@Test
void testFinish()
{
SnowballStemmer stemmer = new SnowballStemmer(ALGORITHM.FINNISH);
// https://snowballstem.org/algorithms/finnish/stemmer.html
Assertions.assertEquals("edeltän", stemmer.stem("edeltäneeseen")); //r_LONG()
Assertions.assertEquals("no-idea-what-the-right-stem-is-but-will-trigger-r_VI()
case.", stemmer.stem("voitaisiin")); // r_VI()
}
{code}
*edeltäneeseen* will trigger:
*private boolean opennlp.tools.stemmer.snowball.finnishStemmer.r_LONG()*
*voitaisiin* will trigger the other case:
*private boolean opennlp.tools.stemmer.snowball.finnishStemmer.r_VI()*
*Note, the exception is swallowed, so we need to set a break point in
SnowballProgram line 356.*
was (Author: rzo1):
For finish, this exception can only happen for the following Among elements
contained in a_6 (as method name is set)
{code:java}
new Among ( "den", 11, -1, "r_VI", methodObject )
new Among ( "seen", 11, -1, "r_LONG", methodObject )
new Among ( "tten", 11, -1, "r_VI", methodObject ){code}
It can be reproduced by
{code:java}
@Test
void testFinish()
{
SnowballStemmer stemmer = new SnowballStemmer(ALGORITHM.FINNISH);
// https://snowballstem.org/algorithms/finnish/stemmer.html
Assertions.assertEquals("edeltän", stemmer.stem("edeltäneeseen")); //r_LONG()
Assertions.assertEquals("no-idea-what-the-right-stem-is-but-will-trigger-r_VI()
case.", stemmer.stem("voitaisiin")); // r_VI()
}
{code}
which will try to invoke
*private boolean opennlp.tools.stemmer.snowball.finnishStemmer.r_LONG()*
Note, the exception is swallowed, so we need to set a break point in
SnowballProgram line 356.
*voitaisiin* will trigger the other case:
*private boolean opennlp.tools.stemmer.snowball.finnishStemmer.r_VI()*
> Generated Java code for stemmers is broken, and should be re-generated
> ----------------------------------------------------------------------
>
> Key: OPENNLP-1520
> URL: https://issues.apache.org/jira/browse/OPENNLP-1520
> Project: OpenNLP
> Issue Type: Bug
> Components: Stemmer
> Affects Versions: 2.3.0, 2.3.1
> Reporter: Jon Marius Venstad
> Assignee: Martin Wiesner
> Priority: Major
> Fix For: 2.3.2
>
>
> The recursive stemming, which seems hard to actually trigger, but which is
> the intended usage of the {{methodObject and method}} in the {{Among}} class
> (called reflectively) is completely broken. First off, it tries to invoke a
> private method from outside the class (from a parent class, the
> {{{}SnowballProgram{}}}), which fails with an illegal access exception; if
> that worked, it would also have invoked _all_ such method calls on the
> {_}same, shared, static object{_}—not on the relevant stemmer instance.
> This was fixed 8 years ago, but it looks like the generated code in the
> opennlp-tools is 10 years old. I would urge you to re-generate that code.
>
> Commit that fixed the Java code generation:
> [https://github.com/snowballstem/snowball/commit/0f9d3d64ab965447a7f638b8ededc924f3efca75]
>
> Relevant sample stemmer with broken Java:
> [https://github.com/apache/opennlp/blob/main/opennlp-tools/src/main/java/opennlp/tools/stemmer/snowball/finnishStemmer.java]
>
> Stack trace showing illegal reflection access:
>
> {noformat}
> 2023-10-26 23:21:44.200 class opennlp.tools.stemmer.snowball.SnowballProgram
> cannot access a member of class opennlp.tools.stemmer.snowball.finnishStemmer
> with modifiers "private"
> exception=java.lang.IllegalAccessException: class
> opennlp.tools.stemmer.snowball.SnowballProgram cannot access a member of
> class opennlp.tools.stemmer.snowball.finnishStemmer with modifiers "private"
> at
> java.base/jdk.internal.reflect.Reflection.newIllegalAccessException(Reflection.java:392)
>
> at
> java.base/java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:674)
>
> at java.base/java.lang.reflect.Method.invoke(Method.java:560)
> at
> opennlp.tools.stemmer.snowball.SnowballProgram.find_among_b(SnowballProgram.java:353)
>
> at
> opennlp.tools.stemmer.snowball.finnishStemmer.r_case_ending(finnishStemmer.java:480)
>
> at
> opennlp.tools.stemmer.snowball.finnishStemmer.stem(finnishStemmer.java:1003)
> at
> opennlp.tools.stemmer.snowball.SnowballStemmer.stem(SnowballStemmer.java:131)
> at
> com.yahoo.language.opennlp.OpenNlpTokenizer.processToken(OpenNlpTokenizer.java:64)
>
> at
> com.yahoo.language.opennlp.OpenNlpTokenizer.lambda$tokenize$0(OpenNlpTokenizer.java:54)
>
> at
> com.yahoo.language.simple.SimpleTokenizer.tokenize(SimpleTokenizer.java:74)
> at
> com.yahoo.language.opennlp.OpenNlpTokenizer.tokenize(OpenNlpTokenizer.java:54)
>
> at
> com.yahoo.vespa.indexinglanguage.linguistics.LinguisticsAnnotator.annotate(LinguisticsAnnotator.java:76)
> ...{noformat}
>
>
> Best, Jon Marius Venstad, developer at [vespa.ai|http://vespa.ai/]
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