lucene的锁机制IndexWriter

1&＃xff1a;lucene中打开一个IndexWriter后就会把索引改lock住&＃xff0c;如果强行在打开一个IndexWriter那么就会抛出&＃xff1a;

Lock obtain timed out: NativeFSLock&＃64;D:\lucene\index\write.lock异常。

2&＃xff1a;所以在Lucene中要记得及时关闭IndexWriter。

package com.searchtxt.lucene;import java.io.File;
import java.io.IOException;import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
import org.junit.Before;
import org.junit.Test;
import org.wltea.analyzer.lucene.IKAnalyzer;import com.sun.org.apache.xml.internal.security.Init;/*** 测试lucene索引锁不能同时打开多个IndexWriter* &＃64;author lijunqing**/
public class WriteLcok {private Directory directory;private Analyzer analyzer;&＃64;Beforepublic void Init() throws IOException{directory &＃61; FSDirectory.open(new File("D://lucene/index"));analyzer &＃61; new IKAnalyzer();}&＃64;Testpublic void TestWriteLock() throws IOException{IndexWriterConfig iwc &＃61; new IndexWriterConfig(Version.LUCENE_40, analyzer );IndexWriter writer1 &＃61; new IndexWriter(directory, iwc);//writer1.close();IndexWriter writer2 &＃61; null;try{if(writer1.isLocked(directory)){System.out.println("writer1已经被锁");}writer2 &＃61; new IndexWriter(directory, iwc);System.out.println("第二个IndexWriter打开成功&＃xff01;");}catch(IOException e){e.printStackTrace();System.out.println("第二个IndexWriter打开失败&＃xff01;");}finally{writer1.close();}}
}


 1&＃xff1a;结果会抛出异常&＃xff0c;

同时lucene的IndexWrite中有&＃xff1a;

public static boolean isLocked(Directory directory) throws IOException {return directory.makeLock(WRITE_LOCK_NAME).isLocked();}

 检查索引是否已经被锁。

而unlock方法&＃xff0c;释放当前锁&＃xff1a;

public static void unlock(Directory directory) throws IOException {directory.makeLock(IndexWriter.WRITE_LOCK_NAME).release();}  不能乱用这个。