lucene自定义过滤器

package util;import java.io.IOException;import org.apache.lucene.index.IndexReader;import org.apache.lucene.index.Term;import org.apache.lucene.index.TermDocs;import org.apache.lucene.search.DocIdSet;import org.apache.lucene.search.Filter;import org.apache.lucene.search.IndexSearcher;import org.apache.lucene.search.Query;import org.apache.lucene.search.TermQuery;import org.apache.lucene.search.TopDocs;import org.apache.lucene.util.OpenBitSet;/** * 过滤指定的文件名 * @author user * */public class MyIDFilter extends Filter{public static void main(String[] args) throws Exception {IndexSearcher searcher = DocUtil.getSearcher();Query query = new TermQuery(new Term("content","java"));Filter filterFilename = new MyIDFilter();//TopDocs topdoc = searcher.search(query, 100);TopDocs topdoc = searcher.search(query, filterFilename, 100);DocUtil.printDocument(topdoc, searcher);searcher.close();}private String[] filenames = {"1.txt","2.txt","3.txt"};@Overridepublic DocIdSet getDocIdSet(IndexReader reader) throws IOException {//创建一个元素bitset,默认所有的元素都是0OpenBitSet obs = new OpenBitSet(reader.maxDoc());//先把元素填满,只要有传入的文档号被设置,该文档的对应元素就会被设置为1obs.set(0, reader.maxDoc() - 1);int[] docs = new int[1];//存储查询出来的对象的位置int[] freqs = new int[1];//存储查询出来的对象出现的频率//根据id所在的doc位置,并且将其设置为0for(String filename : filenames){//获取TermDocsTermDocs tds = reader.termDocs(new Term("filename",filename));//会将查询出来的对象的位置存储到docs中,出现的频率存储到freqs中,返回获取的条数int count = tds.read(docs, freqs);if(count == 1){//将这个元素删除obs.clear(docs[0]);}}return obs;}}