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;
}
}
作者：jadyer 发表于2013-8-19 11:52:24 原文链接
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