使用Java的Lucene搜索工具对检索结果进行分组和分页

public class IndexHelper {
  private Document document;
  private Directory directory;
  private IndexWriter indexWriter;
 
  public Directory getDirectory(){
    directory=(directory==null)? new RAMDirectory():directory;
    return directory;
  }
 
  private IndexWriterConfig getConfig() {
    return new IndexWriterConfig(Version.LUCENE_43, new IKAnalyzer(true));
  }
 
  private IndexWriter getIndexWriter() {
    try {
      return new IndexWriter(getDirectory(), getConfig());
    } catch (IOException e) {
      e.printStackTrace();
      return null;
    }
  }
 
  public IndexSearcher getIndexSearcher() throws IOException {
    return new IndexSearcher(DirectoryReader.open(getDirectory()));
  }
 
  /**
   * Create index for group test
   * @param author
   * @param content
   */
  public void createIndexForGroup(int id,String author,String content) {
    indexWriter = getIndexWriter();
    document = new Document();
    document.add(new IntField("id",id, Field.Store.YES));
    document.add(new StringField("author", author, Field.Store.YES));
    document.add(new TextField("content", content, Field.Store.YES));
    try {
      indexWriter.addDocument(document);
      indexWriter.commit();
      indexWriter.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

public class GroupTest

public void group(IndexSearcher indexSearcher,String groupField,String content) throws IOException, ParseException {
    GroupingSearch groupingSearch = new GroupingSearch(groupField);
    groupingSearch.setGroupSort(new Sort(SortField.FIELD_SCORE));
    groupingSearch.setFillSortFields(true);
    groupingSearch.setCachingInMB(4.0, true);
    groupingSearch.setAllGroups(true);
    //groupingSearch.setAllGroupHeads(true);
    groupingSearch.setGroupDocsLimit(10);
 
    QueryParser parser = new QueryParser(Version.LUCENE_43, "content", new IKAnalyzer(true));
    Query query = parser.parse(content);
 
    TopGroups<BytesRef> result = groupingSearch.search(indexSearcher, query, 0, 1000);
 
    System.out.println("搜索命中数：" + result.totalHitCount);
    System.out.println("搜索结果分组数：" + result.groups.length);
 
    Document document;
    for (GroupDocs<BytesRef> groupDocs : result.groups) {
      System.out.println("分组：" + groupDocs.groupValue.utf8ToString());
      System.out.println("组内记录：" + groupDocs.totalHits);
 
      //System.out.println("groupDocs.scoreDocs.length:" + groupDocs.scoreDocs.length);
      for (ScoreDoc scoreDoc : groupDocs.scoreDocs) {
        System.out.println(indexSearcher.doc(scoreDoc.doc));
      }
    }
  }

public static void main(String[] args) throws IOException, ParseException {
    IndexHelper indexHelper = new IndexHelper();
    indexHelper.createIndexForGroup(1,"红薯", "开源中国");
    indexHelper.createIndexForGroup(2,"红薯", "开源社区");
    indexHelper.createIndexForGroup(3,"红薯", "代码设计");
    indexHelper.createIndexForGroup(4,"红薯", "设计");
    indexHelper.createIndexForGroup(5,"觉先", "Lucene开发");
    indexHelper.createIndexForGroup(6,"觉先", "Lucene实战");
    indexHelper.createIndexForGroup(7,"觉先", "开源Lucene");
    indexHelper.createIndexForGroup(8,"觉先", "开源solr");
 
    indexHelper.createIndexForGroup(9,"散仙", "散仙开源Lucene");
    indexHelper.createIndexForGroup(10,"散仙", "散仙开源solr");
    indexHelper.createIndexForGroup(11,"散仙", "开源");
    GroupTest groupTest = new GroupTest();
 
    groupTest.group(indexHelper.getIndexSearcher(),"author", "开源");
  }
}

ScoreDoc[] sd = XXX;
// 查询起始记录位置
int begin = pageSize * (currentPage - 1);
// 查询终止记录位置
int end = Math.min(begin + pageSize, sd.length);
for (int i = begin; i < end && i <totalHits; i++) {
//对搜索结果数据进行处理的代码
}

//可以使用Map保存必要的搜索结果
Map<String, Object> resultMap = new HashMap<String, Object>();
ScoreDoc after = null;
Query query = XX
TopDocs td = search.searchAfter(after, query, size);
 
//获取命中数
resultMap.put("num", td.totalHits);
 
ScoreDoc[] sd = td.scoreDocs;
for (ScoreDoc scoreDoc : sd) {
//经典的搜索结果处理
}
//搜索结果ScoreDoc总量减1
after = sd[td.scoreDocs.length - 1]; 
//保存after用于下次搜索，即下一页开始 
resultMap.put("after", after);
 
return resultMap;