Lucene之——第一个Lucene3.0程序

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我们模拟一个对商品的操作流程，通过对商品信息的操作, 演示Lucene插入、查询功能, 了解Lucene存储原理。

创建数据操作实体类Goods：

public class Goods {
private Integer gid;
private String gname;
private Double gprice;
private String remark;
// 省略 get set方法
}

创建索引代码

public void addIndex(Goods goods) {
// 声明 索引、目录、分词器 变量
IndexWriter indexWriter = null;
Directory directory = null;
Analyzer analyzer = null;
try {
// 创建一个简单的分词器,可以对数据进行分词
analyzer = new StandardAnalyzer(Version.LUCENE_30);
// Creates an FSDirectory instance
directory = FSDirectory.open(new File("./indexData"));
// 创建索引操作的工具类,用于对索引的 插入、更新、删除操作
indexWriter = new IndexWriter(directory, analyzer,
MaxFieldLength.LIMITED);
// 把Goods对象转化为Lucene可以识别的Document对象
Document doc = new Document();
doc.add(new Field("gid", goods.getGid().toString(), Store.YES,Index.NOT_ANALYZED));
doc.add(new Field("gname", goods.getGname(), Store.YES,
Index.ANALYZED));
doc.add(new Field("gprice", goods.getGprice().toString(),
Store.YES, Index.NOT_ANALYZED));
doc.add(new Field("gremark", goods.getRemark(), Store.YES,
Index.NO));
// 添加到索引库中
indexWriter.addDocument(doc);
// 提交索引数据
indexWriter.commit();
} catch (Exception e) {
new RuntimeException(e);
} finally {
try {
indexWriter.close();
} catch (Exception e) {
new RuntimeException(e);
}
}
}

测试用例如下：

@Test
public void testAddIndex(){
Goods goods=new Goods();
goods.setGid(12345);
goods.setGname("IBM笔记本电脑");
goods.setGprice(34.56);
goods.setRemark("IBM笔记本电脑, 小黑 永恒的经典....");
helloWorld.addIndex(goods);
}

查询索引代码：

// 查询索引
public List<Goods> queryIndex(String gname) {
List<Goods> goodsList = new ArrayList<Goods>();
Directory directory = null;
IndexSearcher indexSearcher = null;
try {
// 获取索引库
directory = FSDirectory.open(new File("./indexData"));
// 创建查询索引工具类
indexSearcher = new IndexSearcher(directory);
// 把查询字符串转化为Query对象
QueryParser queryParse = new QueryParser(Version.LUCENE_30,"gname",Configuraction.getAnalyzer());
Query query=queryParse.parse(gname);
// int totalHits: 存储了.通过查询条件查询到的总共的数量
// ScoreDoc[]: 存储了命中文档的逻辑编号,Lucenen自动生成的编号
TopDocs topDocs = indexSearcher.search(query, 10);
System.out.println("查询到的总结果数为:" + topDocs.totalHits);
for (int i = 0; i < topDocs.totalHits; i++) {
ScoreDoc temp = topDocs.scoreDocs[i];
System.out.println("当前doc在索引库中的编号为:" + temp.doc);
// 通过编号去查找相应的document
Document doc = indexSearcher.doc(temp.doc);
Goods goods = new Goods();
goods.setGid(Integer.parseInt(doc.get("gid")));
goods.setGname(doc.get("gname"));
goods.setGprice(Double.parseDouble(doc.get("gprice")));
goods.setRemark(doc.get("gremark"));
goodsList.add(goods);
}
} catch (IOException e) {
new RuntimeException(e);
}finally{
try {
indexSearcher.close();
} catch (IOException e) {
new RuntimeException(e);
}
}
return goodsList;
}

测试用例如下：

@Test
public void testQueryIndex(){
for(Goods goods:helloWorld.queryIndex("ibm")){
System.out.println(goods.getGid());
System.out.println(goods.getGname());
System.out.println(goods.getRemark());
System.out.println(goods.getGprice());
}
}

查询结果如下：

查询到的总结果数为:1
当前doc在索引库中的编号为:0
12345
IBM笔记本电脑
IBM笔记本电脑, 小黑 永恒的经典....
34.56