lucene5(2)索引增删改查

1、增加索引

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@Test
public void TestInsert() throws Exception {
IndexWriter writer = getIndexWriter(indexDir);
Document document = new Document();
// 添加一个文档信息,相当于一个数据库表字段
document.add(new TextField("name", "hello world", Field.Store.YES));
document.add(new TextField("describes", "测试luence", Field.Store.YES));
writer.addDocument(document);
writer.close();
}

2、更新索引

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@Test
public void TestUpdate() throws Exception {
// Lucene并没有提供更新,这里的更新操作相当于新增,他并不会去掉原来的信息
IndexWriter writer = getIndexWriter(indexDir);
Document doc = new Document();
doc.add(new StringField("name", "ckl", Field.Store.YES));
doc.add(new StringField("describes", "chenkailing", Field.Store.YES));
writer.updateDocument(new Term("name", "hello world"), doc);
//需要将原来的索引删除
// TODO
writer.close();
}

3、删除索引

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@Test
public void TestDelete() throws Exception {
IndexWriter writer = getIndexWriter(indexDir);
QueryParser parser = new QueryParser("name", getAnalyzer());
Query query = parser.parse("ckl");
// 此时删除的文档并不会被完全删除,而是存储在一个回收站中的,可以恢复
writer.deleteDocuments(query);
// 强制合并删除的索引信息,索引量大的时候不推荐使用,真正的删除
writer.forceMergeDeletes();
//更改索引要提交,和提交数据库事务一个概念,真正的删除
writer.commit();
writer.close();
}

4、查询索引

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@Test
public void TestSearch() throws Exception {
IndexReader reader = getIndexReader();
IndexSearcher searcher = new IndexSearcher(reader);
// 指定Document的某个属性
QueryParser parser = new QueryParser("name", getAnalyzer());
// 指定索引内容,对应某个分词
Query query = parser.parse("ckl");
TopDocs hits = searcher.search(query, 10);
for (ScoreDoc sd : hits.scoreDocs) {
Document doc = searcher.doc(sd.doc);
System.out.println("name:" + doc.get("name") + ",describes:" + doc.get("describes"));
}
reader.close();
}

5、读取索引信息

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public static IndexReader getIndexReader() throws Exception {
IndexReader reader = null;
reader = DirectoryReader.open(getDirectory(indexDir));
// 通过reader可以有效的获取到文档的数量
System.out.println("当前存储的文档数:" + reader.numDocs());
System.out.println("回收站的文档数:" + reader.numDeletedDocs());
System.out.println("当前存储的文档数,包含回收站的文档:" + reader.maxDoc());
return reader;
}