【Lucene3.6.2入门系列】第07节_高级搜索之普通Filter和自定义Filter

x33g5p2x  于2021-12-24 转载在 其他  
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完整版见https://jadyer.github.io/2013/08/19/lucene-advanced-search-filter/

package com.jadyer.lucene;

import java.io.File;
import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.NumericField;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

import com.jadyer.custom.MyFilter;

/**
 * 【Lucene3.6.2入门系列】第07节_高级搜索之普通Filter和自定义Filter
 * @create Aug 19, 2013 11:13:40 AM
 * @author 玄玉<http://blog.csdn.net/jadyer>
 */
public class AdvancedSearchByFilter {
	private Directory directory;
	private IndexReader reader;
	
	public AdvancedSearchByFilter(){
		/**文件大小*/
		int[] sizes = {90, 10, 20, 10, 60, 50};
		/**文件名*/
		String[] names = {"Michael.java", "Scofield.ini", "Tbag.txt", "Jack", "Jade", "Jadyer"};
		/**文件内容*/
		String[] contents = {"my java blog is http://blog.csdn.net/jadyer",
							 "my Java Website is http://www.jadyer.cn",
							 "my name is jadyer",
							 "I am a Java Developer",
							 "I am from Haerbin",
							 "I like java of Lucene"};
		/**文件日期*/
		Date[] dates = new Date[sizes.length];
		SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd HH:mm:ss");
		IndexWriter writer = null;
		Document doc = null;
		try {
			dates[0] = sdf.parse("20130407 15:25:30");
			dates[1] = sdf.parse("20130407 16:30:45");
			dates[2] = sdf.parse("20130213 11:15:25");
			dates[3] = sdf.parse("20130808 09:30:55");
			dates[4] = sdf.parse("20130526 13:54:22");
			dates[5] = sdf.parse("20130701 17:35:34");
			directory = FSDirectory.open(new File("myExample/01_index/"));
			writer = new IndexWriter(directory, new IndexWriterConfig(Version.LUCENE_36, new StandardAnalyzer(Version.LUCENE_36)));
			writer.deleteAll();
			for(int i=0; i<sizes.length; i++){
				doc = new Document();
				doc.add(new NumericField("size",Field.Store.YES, true).setIntValue(sizes[i]));
				doc.add(new Field("name", names[i], Field.Store.YES, Field.Index.ANALYZED_NO_NORMS));
				doc.add(new Field("content", contents[i], Field.Store.NO, Field.Index.ANALYZED));
				doc.add(new NumericField("date", Field.Store.YES, true).setLongValue(dates[i].getTime()));
				//为每个文档添加一个fileID(与ScoreDoc.doc不同),专门在自定义Filter时使用
				doc.add(new Field("fileID", String.valueOf(i), Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS));
				writer.addDocument(doc);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if(null != writer){
				try {
					writer.close();
				} catch (IOException ce) {
					ce.printStackTrace();
				}
			}
		}
	}
	
	/**
	 * 获取IndexReader实例
	 */
	private IndexReader getIndexReader(){
		try {
			if(reader == null){
				reader = IndexReader.open(directory);
			}else{
				//if the index was changed since the provided reader was opened, open and return a new reader; else,return null
				//如果当前reader在打开期间index发生改变,则打开并返回一个新的IndexReader,否则返回null
				IndexReader ir = IndexReader.openIfChanged(reader);
				if(ir != null){
					reader.close(); //关闭原reader
					reader = ir;    //赋予新reader
				}
			}
			return reader;
		}catch(Exception e) {
			e.printStackTrace();
		}
		return null; //发生异常则返回null
	}
	
	
	/**
	 * 搜索过滤
	 */
	public void searchByFilter(String expr, Filter filter){
		IndexSearcher searcher = new IndexSearcher(this.getIndexReader());
		QueryParser parser = new QueryParser(Version.LUCENE_36, "content", new StandardAnalyzer(Version.LUCENE_36));
		TopDocs tds = null;
		try {
			if(null == filter){
				tds = searcher.search(parser.parse(expr), 10);
			}else{
				tds = searcher.search(parser.parse(expr), filter, 10);
			}
			for(ScoreDoc sd : tds.scoreDocs){
				Document doc = searcher.doc(sd.doc);
				System.out.print("文档编号=" + sd.doc + "  文档权值=" + doc.getBoost() + "  文档评分=" + sd.score + "    ");
				System.out.println("fileID=" + doc.get("fileID") + "  size=" + doc.get("size") + "  date=" + new SimpleDateFormat("yyyyMMdd HH:mm:ss").format(new Date(Long.parseLong(doc.get("date")))) + "  name=" + doc.get("name"));
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if(searcher != null){
				try {
					searcher.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
	
	
	/**
	 * 测试一下过滤效果
	 */
	public static void main(String[] args) throws ParseException {
		AdvancedSearchByFilter advancedSearch = new AdvancedSearchByFilter();
//		//过滤文件名首字母从'h'到'n'的记录(注意hn要小写)
//		advancedSearch.searchByFilter("Java", new TermRangeFilter("name", "h", "n", true, true));
//		//过滤文件大小在30到80以内的记录
//		advancedSearch.searchByFilter("Java", NumericRangeFilter.newIntRange("size", 30, 80, true, true));
//		//过滤文件日期在20130701 00:00:00到20130808 23:59:59之间的记录
//		Long min = Long.valueOf(new SimpleDateFormat("yyyyMMdd").parse("20130701").getTime());
//		Long max = Long.valueOf(new SimpleDateFormat("yyyyMMdd HH:mm:ss").parse("20130808 23:59:59").getTime());
//		advancedSearch.searchByFilter("Java", NumericRangeFilter.newLongRange("date", min, max, true, true));
//		//过滤文件名以'ja'打头的(注意ja要小写)
//		advancedSearch.searchByFilter("Java", new QueryWrapperFilter(new WildcardQuery(new Term("name", "ja*"))));
		//自定义Filter
		advancedSearch.searchByFilter("Java", new MyFilter());
	}
}

下面是自定义的MyFilter.java

package com.jadyer.custom;

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.util.OpenBitSet;

/**
 * 自定义Filter
 * @see ------------------------------------------------------------------------------------------
 * @see 本例的应用场景
 * @see 假设很多的数据,然后删除了其中的某几条数据,此时在接受搜索请求时为保证不会搜索到已删除的数据
 * @see 那么可以更新索引,但更新索引会消耗很多时间(因为数据量大),而又要保证已删除的数据不会被搜索到
 * @see 此时就可以自定义Filter,原理即搜索过程中,当发现此记录为已删除记录,则不添加到返回的搜索结果集中
 * @see ------------------------------------------------------------------------------------------
 * @see 自定义Filter步骤如下
 * @see 1)继承Filter类并重写getDocIdSet()方法
 * @see 2)根据实际过滤要求返回新的DocIdSet对象
 * @see ------------------------------------------------------------------------------------------
 * @see DocIdSet小解
 * @see 这里Filter干的活其实就是创建一个DocIdSet,而DocIdSet其实就是一个数组,可以理解为其中只存放0或1的值
 * @see 每个搜索出来的Document都有一个文档编号,所以搜索出来多少个Document,那么DocIdSet中就会有多少条记录
 * @see 而DocIdSet中每一条记录的索引号与文档编号是一一对应的
 * @see 所以当DocIdSet中的记录为1时,则对应文档编号的Document就会被添加到TopDocs中,为0就会被过滤掉
 * @see ------------------------------------------------------------------------------------------
 * @create Aug 6, 2013 7:28:53 PM
 * @author 玄玉<http://blog.csdn.net/jadyer>
 */
public class MyFilter extends Filter {
	private static final long serialVersionUID = -8955061358165068L;
	
	//假设这是已删除记录的fileID值的集合
	private String[] deleteFileIDs = {"1", "3"};
	
	@Override
	public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
		//创建一个DocIdSet的子类OpenBitSet(创建之后默认所有元素都是0),传的参数就是本次"搜索到的"元素数目
		OpenBitSet obs = new OpenBitSet(reader.maxDoc());
		//先把元素填满,即全部设置为1
		obs.set(0, reader.maxDoc());
		//用于保存已删除元素的文档编号
		int[] docs = new int[1];
		for(String deleteDataID : deleteFileIDs){
			//获取已删除元素对应的TermDocs
			TermDocs tds = reader.termDocs(new Term("fileID", deleteDataID));
			//将已删除元素的文档编号放到docs中,将其出现的频率放到freqs中,最后返回查询出来的元素数目
			int count = tds.read(docs, new int[1]);
			if(count == 1){
				//将这个位置docs[0]的元素删除
				obs.clear(docs[0]);
			}
		}
		return obs;
	}
}

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