Practice Every Day_16（添加索引）

                           今天敲的代码是添加索引的代码，之前看视频讲解的是更新索引，但有很大的局限（必须先删除之后再添加索引），现在学了实时索引之后就不用那样做了，可以直接向原有索引里添加新的索引。以下是代码：

//创建IndexField类，可以通过这个类来添加需要创建索引的内容

package Lucy;

import java.security.MessageDigest;

public class IndexField
{
 private String id; 
 private String title;
 private String content;
 public void setId(String id)
 {
  this.id=id;
 }
 public String getId()
 {
  return id;
 }
 public void setTitle(String title)
 {
  this.title=title;
 }
 public String getTitle()
 {
  return title;
 }
 public void setContent(String content)
 {
  this.content=content;
 }
 public String getContent()
 {
  return content;
 }
 

}

//通过该类创建管理Index的NRTManager

package Lucy;

import java.io.File;
import java.io.IOException;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.NRTManager;
import org.apache.lucene.search.NRTManagerReopenThread;
import org.apache.lucene.search.SearcherManager;
import org.apache.lucene.search.SearcherWarmer;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

public class LuceneContext
{
    private static LuceneContext instance;
    private static final String path="e:Lucene_Index";
    private static IndexWriter writer;
    private static Analyzer analyzer;
    private static NRTManager nrtMgr;
    private static SearcherManager mgr;
    private static Directory directory;
    private static Version version;
   
    public static LuceneContext getInstance()
    {
     if(instance==null)
     {
      init();
      instance=new LuceneContext();
     }
     return instance;
    }
    private static void init()
    {
     try
      {
     directory=FSDirectory.open(new File(path));
     version=Version.LUCENE_35;
     //String s=LuceneContext.class.getClassLoader().getResource("data").getPath();
     analyzer=new StandardAnalyzer(version);
     writer=new IndexWriter(directory,new IndexWriterConfig(version,analyzer));
     nrtMgr=new NRTManager(writer,new SearcherWarmer()
     {
      public void warm(IndexSearcher s)throws IOException
      {
       System.out.println("reopen"); 
      }
     }  
     );
     NRTManagerReopenThread reopen=new NRTManagerReopenThread(nrtMgr,5.0,0.025);
     reopen.setDaemon(true);
     reopen.start();
      }
     catch(IOException e)
     {
      e.printStackTrace();
     }
    }
    public IndexSearcher getSearcher()
    {
     return mgr.acquire();
    }
    public void releaseSearcher(IndexSearcher searcher)
    {
     try{
      mgr.release(searcher);
        }
     catch(IOException e)
     {
      e.printStackTrace();
     }
    }
    public static void commitIndex() throws CorruptIndexException, IOException
    {
     writer.commit();
    }
    public NRTManager getNRTManager()
    {
     return nrtMgr;
    }
    public static void check() throws IOException
    {      //检查索引是否被正确建立(打印索引)
    FSDirectory directory = FSDirectory.open(new File(path));
    IndexReader reader = IndexReader.open(directory);
    for(int i = 0;i<reader.numDocs();i++)
    {
     System.out.println(reader.document(i));
    }
      }
}
//测试类

package Lucy;
import java.io.IOException;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;

import org.apache.lucene.search.NRTManager;

public class Test
{ 
 public static void main(String[] args) throws IOException
 {
   IndexField fields=new IndexField();
        fields.setId("01");
        fields.setTitle("我的大学");
        fields.setContent("我的大学坐落在美丽的海滨城市--烟台");
        LuceneContext.check();
        //addIndex(fields);
       // LuceneContext.commitIndex();
 }

//通过该方法直接添加索引
  public static void addIndex(IndexField fields)
 {
   try{
   NRTManager nrtMgr=LuceneContext.getInstance().getNRTManager();
   Document doc=field2Doc(fields);
   nrtMgr.addDocument(doc);
     }
   catch(IOException e)
   {
    e.printStackTrace();
   }
 }

//通过该方法添加Document的域
  private static Document field2Doc(IndexField field)
  {
   Document doc=new Document();
      doc.add(new Field("id",field.getId(),Field.Store.YES,Field.Index.NOT_ANALYZED));
      doc.add(new Field("title",field.getTitle(),Field.Store.YES,Field.Index.ANALYZED));
      doc.add(new Field("content",field.getContent(),Field.Store.YES,Field.Index.ANALYZED));
      return doc;
  }
 
}

不足之处：1、存在重复建立索引的问题

                    2、当只需要添加一个域是没法执行