Rileva nomi inglesi duplicati

Userei un SynonymFilter su firstName durante l'indicizzazione, in modo da avere tutte le possibili combinazioni (Bob -> Robert, Robert -> Bob, ecc...). Indicizza gli utenti esistenti che hai.

Quindi usa QueryParser (senza SynonymFilter nell'analizzatore) per porre alcune query fuzzy.

Questo è il codice che mi è venuto in mente:

public class NameDuplicateTests {
    private Analyzer analyzer;
    private IndexSearcher searcher;
    private IndexReader reader;
    private QueryParser qp;

    private final static Multimap<String, String> firstNameSynonyms;
    static {
        firstNameSynonyms = HashMultimap.create();
        List<String> robertSynonyms = ImmutableList.of("Bob", "Bobby", "Robert");
        for (String name: robertSynonyms) {
            firstNameSynonyms.putAll(name, robertSynonyms);
        }
        List<String> willSynonyms = ImmutableList.of("William", "Will", "Bill", "Billy");
        for (String name: willSynonyms) {
            firstNameSynonyms.putAll(name, willSynonyms);
        }
    }

    public static Analyzer createAnalyzer() {
        return new Analyzer() {
            @Override
            public TokenStream tokenStream(String fieldName, Reader reader) {
                TokenStream tokenizer = new WhitespaceTokenizer(reader);
                if (fieldName.equals("firstName")) {
                    tokenizer = new SynonymFilter(tokenizer, new SynonymEngine() {
                        @Override
                        public String[] getSynonyms(String s) throws IOException {
                            return firstNameSynonyms.get(s).toArray(new String[0]);
                        }
                    });
                }
                return tokenizer;
            }
        };
    }


    @Before
    public void setUp() throws Exception {
        Directory dir = new RAMDirectory();
        analyzer = createAnalyzer();

        IndexWriter writer = new IndexWriter(dir, analyzer, IndexWriter.MaxFieldLength.UNLIMITED);
        ImmutableList<String> firstNames = ImmutableList.of("William", "Robert", "Bobby", "Will", "Anton");
        ImmutableList<String> lastNames = ImmutableList.of("Robert", "Williams", "Mayor", "Bob", "FunkyMother");

        for (int id = 0; id < firstNames.size(); id++) {
            Document doc = new Document();
            doc.add(new Field("id", String.valueOf(id), Field.Store.YES, Field.Index.NOT_ANALYZED));
            doc.add(new Field("firstName", firstNames.get(id), Field.Store.YES, Field.Index.ANALYZED));
            doc.add(new Field("lastName", lastNames.get(id), Field.Store.YES, Field.Index.NOT_ANALYZED));
            writer.addDocument(doc);
        }
        writer.close();

        qp = new QueryParser(Version.LUCENE_30, "firstName", new WhitespaceAnalyzer());
        searcher = new IndexSearcher(dir);
        reader = searcher.getIndexReader();
    }

    @After
    public void tearDown() throws Exception {
        searcher.close();
    }

    @Test
    public void testNameFilter() throws Exception {
        search("+firstName:Bob +lastName:Williams");
        search("+firstName:Bob +lastName:Wolliam~");
    }

    private void search(String query) throws ParseException, IOException {
        Query q = qp.parse(query);
        System.out.println(q);
        TopDocs res = searcher.search(q, 3);
        for (ScoreDoc sd: res.scoreDocs) {
            Document doc = reader.document(sd.doc);
            System.out.println("Found " + doc.get("firstName") + " " + doc.get("lastName"));
        }
    }
}

Che si traduce in:

+firstName:Bob +lastName:Williams
Found Robert Williams
+firstName:Bob +lastName:wolliam~0.5
Found Robert Williams

Spero di esserti stato d'aiuto!