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solr  有facet  search  ,BOBO也有；现在lucene3.4之后也有了，这个是贡献版本，在apache 官方的包里面有提供，这种功能对于分组统计和类别统计是一个很好的帮手；

有了这个就不用羡慕solr了，不是我抗拒solr，只是像我们公司有时间让我们开发的情况下，我更偏向于底层点的api开发，lucene更得心应手。

再说现在的solr没有近实时搜索，听说要4.0后有。

废话不说，直接上代码

1. public class Indexer {
2. //需要索引的信息
3. public static String[] docTitles = {
4. “white car”,
5. “white dog”,
6. };
7. public static String[] docTexts = {
8. “the white car is the one I want.”,
9. “the white dog does not belong to anyone.”,
10. };
11. //分的类别
12. public static CategoryPath[] categories = {
13. new CategoryPath(“root”,”a”,”f1″), new CategoryPath(“root”,”a”,”f2″)
14. };
15. public static void index (Directory indexDir, Directory taxoDir) throws Exception {
16. // 创建一个普通的indexwriter
17. IndexWriter iw = new IndexWriter(indexDir, new IndexWriterConfig(ExampleUtils.EXAMPLE_VER, SimpleUtils.analyzer));
18. //创建一个 taxonomy writer
19. TaxonomyWriter taxo = new DirectoryTaxonomyWriter(taxoDir, OpenMode.CREATE);
20. int nDocsAdded = 0;
21. int nFacetsAdded = 0;
22. for (int docNum=0; docNum<docTexts.length; docNum++)
23. {
24. // 准备当前的切面
25. List<CategoryPath> facetList = SimpleUtils.categoryPathArrayToList(categories[0]);
26. //
27. CategoryDocumentBuilder categoryDocBuilder = new CategoryDocumentBuilder(taxo).setCategoryPaths(facetList);
28. // 创建document
29. Document doc = new Document();
30. doc.add(new Field(SimpleUtils.TITLE, docTitles[docNum], Store.YES, Index.ANALYZED));
31. doc.add(new Field(SimpleUtils.TEXT, docTexts[docNum], Store.NO, Index.ANALYZED));
32. // 把切面的索引信息添加到document
33. categoryDocBuilder.build(doc);
34. // 最终写入索引
35. iw.addDocument(doc);
36. nDocsAdded ++;
37. nFacetsAdded += facetList.size();
38. }
39. // commit changes.
40. // we commit changes to the taxonomy index prior to committing them to the search index.
41. // this is important, so that all facets referred to by documents in the search index
42. // will indeed exist in the taxonomy index.
43. taxo.commit();
44. iw.commit();
45. // close the taxonomy index and the index – all modifications are
46. // now safely in the provided directories: indexDir and taxoDir.
47. taxo.close();
48. iw.close();
49. System.out.println(“Indexed “+nDocsAdded+” documents with overall “+nFacetsAdded+” facets.”);
50. }
51. public static void main(String[] args){
52. String indexp = “D:/work/data/index/facet_index/n_index”;
53. String indexp_t = “D:/work/data/index/facet_index/t_index”;
54. try {
55. Directory  directory =  FSDirectory.open(new File(indexp));
56. Directory  directory_t =  FSDirectory.open(new File(indexp_t));
57. new Indexer().index(directory, directory_t);
58. } catch (Exception e) {
59. e.printStackTrace();
60. }
61. }
62. }

1. public class Searcher {
2. public void query(Directory indexDir, Directory taxoDir) throws CorruptIndexException, IOException
3. {
4. Query q = new TermQuery(new Term(SimpleUtils.TEXT, “white”));
5. IndexReader indexReader = IndexReader.open(indexDir, true);
6. IndexSearcher searcher = new IndexSearcher(indexReader);
7. TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir);
8. TopScoreDocCollector topDocsCollector = TopScoreDocCollector.create(10, true);
9. FacetIndexingParams     indexingParams = new DefaultFacetIndexingParams();
10. FacetSearchParams facetSearchParams = new FacetSearchParams(indexingParams);
11. facetSearchParams.addFacetRequest(new CountFacetRequest(new CategoryPath(“root”,”a”), 10));
12. FacetsCollector facetsCollector = new FacetsCollector(facetSearchParams, indexReader, taxoReader);
13. // perform documents search and facets accumulation
14. searcher.search(q, MultiCollector.wrap(topDocsCollector, facetsCollector));
15. // Obtain facets results and print them
16. List<FacetResult> res = facetsCollector.getFacetResults();
17. System.out.println(res.size());
18. int i = 0;
19. for (FacetResult facetResult : res) {
20. System.out.println(“Res ” + (i++) + “: ” + facetResult);
21. System.out.println(“————————————-“);
22. System.out.println( facetResult.getFacetResultNode().getNumSubResults());
23. System.out.println( facetResult.getFacetResultNode().getOrdinal());
24. System.out.println( facetResult.getFacetResultNode().getValue());
25. System.out.println( facetResult.getFacetResultNode().getResidue());
26. }
27. }
28. public static void main(String[] args) {
29. String indexp = “D:/work/data/index/facet_index/n_index”;
30. String indexp_t = “D:/work/data/index/facet_index/t_index”;
31. try {
32. Directory  directory =  FSDirectory.open(new File(indexp));
33. Directory  directory_t =  FSDirectory.open(new File(indexp_t));
34. new Searcher().query(directory, directory_t);
35. } catch (Exception e) {
36. e.printStackTrace();
37. }
38. }
39. }