lucene建立索引时候的用到的一些文档和目录操作

在前边的文章中多是用的添加一个document，这里介绍一下其它的文档操作

1,按照编号删除

public void deleteDoc(String indexDir) throws Exception{
IndexReader reader = IndexReader.open(indexDir);
reader.delete(1);
reader.close();
}

2,根据term来删除

public void deleteDocWithTerm(String indexDir) throws Exception{
IndexReader reader = IndexReader.open(indexDir);
reader.delete(new Term("city","beijing"));
reader.close();
}

3,取消删除

public void undeleteDoc(String indexDir) throws Exception{
IndexReader reader = IndexReader.open(indexDir);
reader.delete(1);
reader.undeleteAll();
reader.close();
}

4,删除后优化

public void mergeDoc(String indexDir) throws Exception{
IndexReader reader = IndexReader.open(indexDir);
reader.delete(new Term("city","beijing"));
reader.close();

IndexWriter writer = new IndexWriter(indexDir,new StandardAnalyzer(),true);
writer.optimize();
writer.close();
}

5,把RAMDirectory中的索引合并到FSDirectroy中

public void indexOperator(String indexDir) throws Exception{
FSDirectory fsDir = FSDirectory.getDirectory(indexDir,true);
RAMDirectory ramDir = new RAMDirectory();
IndexWriter fsWriter = new  IndexWriter(fsDir,new SimpleAnalyzer(),true);
IndexWriter ramWriter = new IndexWriter(ramDir,new SimpleAnalyzer(),true);
//..ramWriter add doc
fsWriter.addIndexes(new Directory[]{ramDir});
ramWriter.close();

}

6,把索引的内容直接读入内存

RAMDirectory ramDir = new RAMDirectory(indexDir);