搜索

搜索

1.创建搜索的索引目录

Directory directory = FSDirectory.open(new File("E:/Lucene/demo"));

2.创建搜索器

IndexSearcher searcher = IndexReader.open(directory);

3.创建搜索条件

Query query = new TermQuery(new Term(field,value)); //索引域field中含有值value的内容

4.执行搜索

TopDocs topDocs = searcher.search(query,count); //根据searcher搜索并返回TopDocs 返回count条

5.根据TopDocs获取ScoreDoc对象数组

ScoreDoc[] scoreDocs = topDocs.scoreDocs;

6.遍历ScoreDoc数组获取Document对象

for (ScoreDoc sd : scoreDocs) {

Document doc = searcher.doc(sd.doc);

String name = doc.get("name");

}

7.关闭IndexSearcher

searcher.close();

 

重难点：

查询条件的选择：

1.精确查询,索引域field=value的内容

Query query = new TermQuery(new Term(field,value));

2.模糊查询字符串,索引域field中以start开始end结尾的内上下区间都包括的内容

Query query = new TermRangeQuery(field, start, end, true, true);

3.模糊查询数值,索引域field中以start开始end结尾的内上下区间都包括的内容

Query query = NumericRangeQuery.newFloatRange(field, min, max, true, true); //newDoubleRange/newIntRange/newLongRange

4.模糊查询以X为前缀的内容,索引域field中以value开头的内容

Query query = new PrefixQuery(new Term(field,value));

5.模糊查询—*通配符查询,索引域field中=*value*的内容,分三种情况,*value/value*/*value*

Query query = new WildcardQuery(new Term(field,value));

6.

 

 

单例的Directory和IndexReader和IndexSearcher

 

private static IndexReader reader;

private static Directory directory;

 

static{

try {

//索引目录

directory = FSDirectory.open(new File("E:/Lucene/demo"));

//读取器

reader = IndexReader.open(directory);

} catch (CorruptIndexException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

}

 

/**

 * 获取查询器

 * @return

 * @author:qiuchen

 */

public static IndexSearcher getSearcher(){

try {

if(reader == null){

reader = IndexReader.open(directory);

}else{

//如果reader发生变化,重新创建

IndexReader ir = IndexReader.openIfChanged(reader);

if(ir != null){

reader.close();//把原来的reader关闭

reader = ir;//重新给reader赋值

}

}

return new IndexSearcher(reader);

} catch (CorruptIndexException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

return null;

}

 

/**

 * 关闭查询器

 * @author:qiuchen

 */

public static void closeSearch(IndexSearcher searcher){

try {

if(searcher != null)

searcher.close();

} catch (IOException e) {

e.printStackTrace();

}

}