The following code prints the output of StandardAnalyzer:
Analyzer analyzer = new StandardAnalyzer();
TokenStream ts = analyzer.tokenStream("content", new StringReader("<some text>"));
while ((t = ts.next()) != null)
If you pass "www.abc.com", the output is (www.abc.com,0,11,type=<HOST>) (which is correct in my opinion).
However, if you pass "www.abc.com." (notice the extra '.' at the end), the output is (wwwabccom,0,12,type=<ACRONYM>).
I think the behavior in the second case is incorrect for several reasons:
1. It recognizes the string incorrectly (no argue on that).
2. It kind of prevents you from putting URLs at the end of a sentence, which is perfectly legal.
3. An ACRONYM, at least to the best of my understanding, is of the form A.B.C. and not ABC.DEF.
I looked at StandardTokenizerImpl.jflex and I think the problem comes from this definition:
// acronyms: U.S.A., I.B.M., etc.
// use a post-filter to remove dots
Notice how the comment relates to acronym as U.S.A., I.B.M. and not something else. I changed the definition to
and it solved the problem.