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[ASP.net教程]关于Lucene 3.0升级到Lucene 4.x 备忘


  最近,需要对项目进行lucene版本升级。而原来项目时基于lucene 3.0的,很古老的一个版本的了。在老版本中中,我们主要用了几个lucene的东西:

  1、查询lucene多目录索引。

  2、构建RAMDirectory,把索引放到内存中,以提高检索效率。

  3、构建Lucene自定义分词。

  4、修改Lucene默认的打分算法。

    下面,将代码改造前和改造后做一对比:

    1. 搜索多索引目录

   3.0 构建多索引目录: 

 1   // 初始化全国索引 2   private boolean InitGlobal(String strRootPath) { 3     try { 4  5       IndexSearcher[] searchers = new IndexSearcher[2]; 6        7       MultiSearcher globalSearcher = null; 8       if (Configution.IsMMap.equalsIgnoreCase("true")) { 9 10         searchers[0] = new IndexSearcher(new RAMDirectory(FSDirectory11             .open(new File(strRootPath + "/" + GLABOL_INDEX))));12         searchers[1] = new IndexSearcher(new RAMDirectory(FSDirectory13             .open(new File(strRootPath + "/" + BUS_INDEX))));14 //        searchers[2] = new IndexSearcher(new RAMDirectory(FSDirectory15 //            .open(new File(strRootPath + "/" + LU_INDEX))));16         globalSearcher = new MultiSearcher(searchers);17       } else {18         searchers[0] = new IndexSearcher(FSDirectory.open(new File(19             strRootPath + "/" + GLABOL_INDEX)));20         searchers[1] = new IndexSearcher(FSDirectory.open(new File(21             strRootPath + "/" + BUS_INDEX)));22 //        searchers[2] = new IndexSearcher(FSDirectory.open(new File(23 //            strRootPath + "/" + LU_INDEX)));24         25         globalSearcher = new MultiSearcher(searchers);26       }27       System.out.println("finish Global");28 29       m_mapIndexName2Searcher.put("0", globalSearcher);30       m_mapAdmin2IndexName.put("0", "0");31 32       return true;33 34     } catch (Exception e) {35       e.printStackTrace();36       SearchLog.SearchLog.error("全国索引初始化异常");37       return false;38     }39   }

     Ok,使用MultiSearcher,这是lucene低版本搜索多索引的解决方案。但是在高版本,MutiSearcher这个类本身都删除了,折腾我很长时间。可见以版本帝著称的Lucene代码设计不是太好。整个lucene代码,接口使用很少,大多是类和抽象类。

       4.x 构建多索引目录: 

	// 初始化全国索引	private boolean InitGlobal(String strRootPath) {		try {						IndexSearcher globalSearcher = null;			if (Configution.IsMMap.equalsIgnoreCase("true")) {								IndexReader irGlobal = DirectoryReader.open(new RAMDirectory(FSDirectory						.open(new File(strRootPath + "/" + GLABOL_INDEX)),new IOContext()));								IndexReader irBus = DirectoryReader.open(new RAMDirectory(FSDirectory						.open(new File(strRootPath + "/" + BUS_INDEX)),new IOContext()));								MultiReader mr = new MultiReader(irGlobal,irBus);								globalSearcher = new IndexSearcher(mr);//new MultiSearcher(searchers);			} else {				IndexReader irGlobal = DirectoryReader.open(FSDirectory						.open(new File(strRootPath + "/" + GLABOL_INDEX)));								IndexReader irBus = DirectoryReader.open(FSDirectory						.open(new File(strRootPath + "/" + BUS_INDEX)));								MultiReader mr = new MultiReader(irGlobal,irBus);				globalSearcher =  new IndexSearcher(mr);//new MultiSearcher(searchers);			}			System.out.println("finish Global");			m_mapIndexName2Searcher.put("0", globalSearcher);			m_mapAdmin2IndexName.put("0", "0");			return true;		} catch (Exception e) {			e.printStackTrace();			SearchLog.SearchLog.error("全国索引初始化异常");			return false;		}	}

  ok 改造后,直接用IndexSearcher替代MultiSearcher,通过传入MultiReader来检索多个索引目录。

  2、构建RAMDirectory,将索引放入内存中。

    3.0 构建内存索引目录:

        searchers[0] = new IndexSearcher(new RAMDirectory(FSDirectory            .open(new File(strRootPath + "/" + GLABOL_INDEX))));        searchers[1] = new IndexSearcher(new RAMDirectory(FSDirectory            .open(new File(strRootPath + "/" + BUS_INDEX))));

    直接将Diretory作为RAMDirectory的构造函数,注意这个动作有坑,如果数据量大,你要等很久的!

    4.x 构建内存索引目录:

        IndexReader irGlobal = DirectoryReader.open(new RAMDirectory(FSDirectory            .open(new File(strRootPath + "/" + GLABOL_INDEX)),new IOContext()));                IndexReader irBus = DirectoryReader.open(new RAMDirectory(FSDirectory            .open(new File(strRootPath + "/" + BUS_INDEX)),new IOContext()));                MultiReader mr = new MultiReader(irGlobal,irBus);

    在4.x中,安装3.0构造方法是不行的,还需要传入一个IOContext对象,汗~~~~~~~~~~~~~~~~

  3、自定义分词:

    3.0 自定义分词:

public class SingleAnalyzer extends Analyzer {  /**   * @param args   */      public TokenStream tokenStream(String fieldName, Reader reader){      TokenStream result = null;      if(fieldName.equals("name"))      {        result = new SingleTokenizer(reader);      }      if(fieldName.equals("totalcity"))      {        result = new IKTokenizer(reader, false);      }    //    result = new StandardFilter(result);//    result = new LowerCaseFilter(result);  //  result = new StopFilter(result, stopSet);    return result;    }    public static void main(String[] args) {    // TODO Auto-generated method stub  }}

  重写tokenStream方法即可,很简单。

    4.x自定义分词:

public class SingleAnalyzer extends Analyzer {  /**   * @param args   */  //    public TokenStream tokenStream(String fieldName, Reader reader){//      TokenStream result = null;//      if(fieldName.equals("name"))//      {//        result = new SingleTokenizer(reader);//      }//      if(fieldName.equals("totalcity"))//      {//        result = new IKTokenizer(reader, false);//      }//    ////    result = new StandardFilter(result);////    result = new LowerCaseFilter(result);//  //  result = new StopFilter(result, stopSet);//    return result;//    }  @Override  protected TokenStreamComponents createComponents(String fieldName,      Reader reader) {    // TODO Auto-generated method stub//     final Tokenizer source = new ChineseTokenizer(reader);//     return new TokenStreamComponents(source, new ChineseFilter(source));    Tokenizer source = null;    if(fieldName.equals("name")){      source = new SingleTokenizer(reader);    }else if(fieldName.equals("totalcity")){      source = new IKTokenizer(reader, false);    }    return new TokenStreamComponents(source, source);  }}

  OK,在4.x中你需要重写createComponents方法。

  4、打分算法:

    3.x和4.x打分算法变化不大,但是命名空间发生了变化,汗~~~~~~~~~~~~

           3.x 命名空间:引入:import org.apache.lucene.search.DefaultSimilarity,命名空间在:org.apache.lucene.search

           4.x命名空间:引入:import org.apache.lucene.search.similarities.*,命名空间在:org.apache.lucene.search.similarities。

  5、查询表达式:主要体现在TermRangeQuery上,3.x版本的一个参数是string类型,但是在4.x版本变成了包了string一层的BytesRef,还有其他很多细节变化

    3.x TermRangerQuery: 

 1     String left = Long 2           .toString((long) (rcBound.m_dLeft * COORDINATE_SCALE_FACTOR)); 3       String right = Long 4           .toString((long) (rcBound.m_dRight * COORDINATE_SCALE_FACTOR)); 5       String top = Long 6           .toString((long) (rcBound.m_dTop * COORDINATE_SCALE_FACTOR)); 7       String bottom = Long 8           .toString((long) (rcBound.m_dBottom * COORDINATE_SCALE_FACTOR)); 9       10       11 12       TermRangeQuery query1 = new TermRangeQuery("lon", left, right,13           true, true);14       TermRangeQuery query2 = new TermRangeQuery("lat", bottom, top,15           true, true);16       searchQuery.add(query1, BooleanClause.Occur.MUST);17       searchQuery.add(query2, BooleanClause.Occur.MUST);

       4.x TermRangerQuery:  

String left = Long          .toString((long) (rcBound.m_dLeft * COORDINATE_SCALE_FACTOR));      String right = Long          .toString((long) (rcBound.m_dRight * COORDINATE_SCALE_FACTOR));      String top = Long          .toString((long) (rcBound.m_dTop * COORDINATE_SCALE_FACTOR));      String bottom = Long          .toString((long) (rcBound.m_dBottom * COORDINATE_SCALE_FACTOR));                  BytesRef brLeft = new BytesRef(left);      BytesRef brRight = new BytesRef(right);      BytesRef brBottom = new BytesRef(bottom);      BytesRef brTop = new BytesRef(top);      TermRangeQuery query1 = new TermRangeQuery("lon",          brLeft, brRight, true, true);      TermRangeQuery query2 = new TermRangeQuery("lat",          brBottom, brTop, true, true);      searchQuery.add(query1, BooleanClause.Occur.MUST);      searchQuery.add(query2, BooleanClause.Occur.MUST);

  6、关闭IndexSearcher

    3.x 关闭IndexSearcher直接调用close方法即可:

 1 public void UnInit() { 2     if (!m_bIsInit) 3       return; 4  5     Iterator iter = m_mapIndexName2Searcher.keySet().iterator(); 6  7     while (iter.hasNext()) { 8  9       String key = (String) iter.next();10 11       MultiSearcher val = (MultiSearcher) m_mapIndexName2Searcher12           .get(key);13 14       try {15   16         val.close();//关闭IndexSearcher17       } catch (IOException e) {18         e.printStackTrace();19         SearchLog.SearchLog.error("分级索引关闭异常");20       }21     }22 23     m_mapIndexName2Searcher.clear();24     m_mapAdmin2IndexName.clear();25     m_mapIndexName2Searcher = null;26     m_mapAdmin2IndexName = null;27     m_bIsInit = false;28   }  

  4.x 关闭IndexSearcher 没有直接close的方法,需要getIndexReader 然后调用IndexReader的close方法:

 1 public void UnInit() { 2     if (!m_bIsInit) 3       return; 4  5     Iterator iter = m_mapIndexName2Searcher.keySet().iterator(); 6  7     while (iter.hasNext()) { 8  9       String key = (String) iter.next();10 11       IndexSearcher val = (IndexSearcher) m_mapIndexName2Searcher12           .get(key);13 14       try {15         val.getIndexReader().close();//关闭IndexSearcher16       } catch (IOException e) {17         e.printStackTrace();18         SearchLog.SearchLog.error("分级索引关闭异常");19       }20     }21 22     m_mapIndexName2Searcher.clear();23     m_mapAdmin2IndexName.clear();24     m_mapIndexName2Searcher = null;25     m_mapAdmin2IndexName = null;26     m_bIsInit = false;27   }

  总之,lucene版本变化很大,如果升级很多方法发送变化,您需要细致观察,多试试,才能升级。升级完成后,最好进行一次功能测试,有些功能可能发生变化甚至错误。升级Lucene不是一件好差事~~~~~~~~~

 

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