Lucene入门+实现
Lucene简介详情见:(https://blog.csdn.net/Regan_Hoo/article/details/78802897)
lucene实现原理
其实网上很多资料表明了,lucene底层实现原理就是倒排索引(invertedindex)。
那么究竟什么是倒排索引呢?
经过Lucene分词之后,它会维护一个类似于“词条--文档ID”的对应关系,当我们进行搜索某个词条的时候,就会得到相应的文档ID。
不同于传统的顺排索引根据一个词,知道有哪几篇文章有这个词。
图解:
Lucene在搜索前自行生成倒排索引,相比数据库中like的模糊搜索效率更高!
Lucene 核心API
-
索引过程中的核心类
- Document文档:他是承载数据的实体(他可以集合信息域Field),是一个抽象的概念,一条记录经过索引之后,就是以一个Document的形式存储在索引文件中的。
- Field:Field 索引中的每一个Document对象都包含一个或者多个不同的域(Field),域是由域名(name)和域值(value)对组成,每一个域都包含一段相应的数据信息。
- IndexWriter:索引过程的核心组件。这个类用于创建一个新的索引并且把文档 加到已有的索引中去,也就是写入操作。
- Directroy:是索引的存放位置,是个抽象类。具体的子类提供特定的存储索引的地址。(FSDirectory 将索引存放在指定的磁盘中,RAMDirectory ·将索引存放在内存中。)
- Analyzer:分词器,在文本被索引之前,需要经过分词器处理,他负责从将被索引的文档中提取词汇单元,并剔除剩下的无用信息(停止词汇),分词器十分关键,因为不同的分词器,解析相同的文档结果会有很大的不同。Analyzer是一个抽象类,是所有分词器的基类。
-
搜索过程中的核心类
- IndexSearcher :IndexSearcher 调用它的search方法,用于搜索IndexWriter 所创建的索引。
- Term :Term 使用于搜索的一个基本单元。
- Query : Query Lucene中含有多种查询(Query)子类。它们用于查询条件的限定其中TermQuery 是Lucene提供的最基本的查询类型,也是最简单的,它主要用来匹配在指定的域(Field)中包含了特定项(Term)的文档。
- TermQuery :Query下的一个子类TermQuery(单词条查询) ,Query lucene中有很多类似的子类。
- TopDocs: 是一个存放有序搜索结果指针的简单容器,在这里搜索的结果是指匹配一个查询条件的一系列的文档。
lucene实现
- 在pom.xml中导入lucene相关依赖
<dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-core</artifactId> <version>5.3.1</version> </dependency> <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-queryparser</artifactId> <version>5.3.1</version> </dependency> <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-analyzers-common</artifactId> <version>5.3.1</version> </dependency>
-
加入工具类LuceneUtil.java
import java.io.IOException;
import java.nio.file.Paths;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.highlight.Formatter;
import org.apache.lucene.search.highlight.Highlighter;
import org.apache.lucene.search.highlight.QueryTermScorer;
import org.apache.lucene.search.highlight.Scorer;
import org.apache.lucene.search.highlight.SimpleFragmenter;
import org.apache.lucene.search.highlight.SimpleHTMLFormatter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.RAMDirectory;
/**
* lucene工具类
* @author Administrator
*
*/
public class LuceneUtil {
/**
* 获取索引文件存放的文件夹对象
*
* @param path
* @return
*/
public static Directory getDirectory(String path) {
Directory directory = null;
try {
directory = FSDirectory.open(Paths.get(path));
} catch (IOException e) {
e.printStackTrace();
}
return directory;
}
/**
* 索引文件存放在内存
*
* @return
*/
public static Directory getRAMDirectory() {
Directory directory = new RAMDirectory();
return directory;
}
/**
* 文件夹读取对象
*
* @param directory
* @return
*/
public static DirectoryReader getDirectoryReader(Directory directory) {
DirectoryReader reader = null;
try {
reader = DirectoryReader.open(directory);
} catch (IOException e) {
e.printStackTrace();
}
return reader;
}
/**
* 文件索引对象
*
* @param reader
* @return
*/
public static IndexSearcher getIndexSearcher(DirectoryReader reader) {
IndexSearcher indexSearcher = new IndexSearcher(reader);
return indexSearcher;
}
/**
* 写入索引对象
*
* @param directory
* @param analyzer
* @return
*/
public static IndexWriter getIndexWriter(Directory directory, Analyzer analyzer)
{
IndexWriter iwriter = null;
try {
IndexWriterConfig config = new IndexWriterConfig(analyzer);
config.setOpenMode(OpenMode.CREATE_OR_APPEND);
// Sort sort=new Sort(new SortField("content", Type.STRING));
// config.setIndexSort(sort);//排序
config.setCommitOnClose(true);
// 自动提交
// config.setMergeScheduler(new ConcurrentMergeScheduler());
// config.setIndexDeletionPolicy(new
// SnapshotDeletionPolicy(NoDeletionPolicy.INSTANCE));
iwriter = new IndexWriter(directory, config);
} catch (IOException e) {
e.printStackTrace();
}
return iwriter;
}
/**
* 关闭索引文件生成对象以及文件夹对象
*
* @param indexWriter
* @param directory
*/
public static void close(IndexWriter indexWriter, Directory directory) {
if (indexWriter != null) {
try {
indexWriter.close();
} catch (IOException e) {
indexWriter = null;
}
}
if (directory != null) {
try {
directory.close();
} catch (IOException e) {
directory = null;
}
}
}
/**
* 关闭索引文件读取对象以及文件夹对象
*
* @param reader
* @param directory
*/
public static void close(DirectoryReader reader, Directory directory) {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
reader = null;
}
}
if (directory != null) {
try {
directory.close();
} catch (IOException e) {
directory = null;
}
}
}
/**
* 高亮标签
*
* @param query
* @param fieldName
* @return
*/
public static Highlighter getHighlighter(Query query, String fieldName)
{
Formatter formatter = new SimpleHTMLFormatter("<span style='color:red'>", "</span>");
Scorer fragmentScorer = new QueryTermScorer(query, fieldName);
Highlighter highlighter = new Highlighter(formatter, fragmentScorer);
highlighter.setTextFragmenter(new SimpleFragmenter(200));
return highlighter;
}
}
-
生成索引(配合测试类dome01展示)
目的:索引数据目录,在指定目录生成索引文件
1、构造方法 实例化IndexWriter
* 获取索引文件存放地址对象
* 获取输出流
设置输出流的对应配置
给输出流配置设置分词器
2、关闭索引输出流
3、索引指定路径下的所有文件
4、索引指定的文件
5、获取文档(索引文件中包含的重要信息,key-value的形式)
6、测试
IndexCreate.java
import java.io.File; import java.io.FileReader; import java.nio.file.Paths; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.document.Field; import org.apache.lucene.document.TextField; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.store.FSDirectory; /** * 配合Demo1.java进行lucene的helloword实现 * @author Administrator * */ public class IndexCreate { private IndexWriter indexWriter; /** * 1、构造方法 实例化IndexWriter * @param indexDir * @throws Exception */ public IndexCreate(String indexDir) throws Exception{ // 获取索引文件的存放地址对象 FSDirectory dir = FSDirectory.open(Paths.get(indexDir)); // 标准分词器(针对英文) Analyzer analyzer = new StandardAnalyzer(); // 索引输出流配置对象 IndexWriterConfig conf = new IndexWriterConfig(analyzer); indexWriter = new IndexWriter(dir, conf); } /** * 2、关闭索引输出流 * @throws Exception */ public void closeIndexWriter() throws Exception{ indexWriter.close(); } /** * 3、索引指定路径下的所有文件 * @param dataDir * @return * @throws Exception */ public int index(String dataDir) throws Exception{ File[] files = new File(dataDir).listFiles(); for (File file : files) { indexFile(file); } return indexWriter.numDocs(); } /** * 4、索引指定的文件 * @param file * @throws Exception */ private void indexFile(File file) throws Exception{ System.out.println("被索引文件的全路径:"+file.getCanonicalPath()); Document doc = getDocument(file); indexWriter.addDocument(doc); } /** * 5、获取文档(索引文件中包含的重要信息,key-value的形式) * @param file * @return * @throws Exception */ private Document getDocument(File file) throws Exception{ Document doc = new Document(); doc.add(new TextField("contents", new FileReader(file))); // Field.Store.YES是否存储到硬盘 doc.add(new TextField("fullPath", file.getCanonicalPath(),Field.Store.YES)); doc.add(new TextField("fileName", file.getName(),Field.Store.YES)); return doc; } }
测试dome01.java
public class Demo1 { public static void main(String[] args) { // 索引文件将要存放的位置 String indexDir = "D:\\lucenetemp\\lucene\\demo1"; // 数据源地址 String dataDir = "D:\\lucenetemp\\lucene\\demo1\\data"; IndexCreate ic = null; try { ic = new IndexCreate(indexDir); long start = System.currentTimeMillis(); int num = ic.index(dataDir); long end = System.currentTimeMillis(); System.out.println("索引指定路径下"+num+"个文件,一共花费了"+(end-start)+"毫秒"); } catch (Exception e) { e.printStackTrace(); }finally { try { ic.closeIndexWriter(); } catch (Exception e) { e.printStackTrace(); } } } }
使用索引
目的:从索引文件中拿数据
1、获取输入流(通过dirReader)
2、获取索引搜索对象(通过输入流来拿)
3、获取查询对象(通过查询解析器来获取,解析器是通过分词器获取)
4、获取包含关键字排前面的文档对象集合
5、可以获取对应文档的内容
IndexUse.java
/** * 配合Demo2.java进行lucene的helloword实现 * @author Administrator * */ public class IndexUse { /** * 通过关键字在索引目录中查询 * @param indexDir 索引文件所在目录 * @param q 关键字 */ public static void search(String indexDir, String q) throws Exception{ FSDirectory indexDirectory = FSDirectory.open(Paths.get(indexDir)); // 注意:索引输入流不是new出来的,是通过目录读取工具类打开的 IndexReader indexReader = DirectoryReader.open(indexDirectory); // 获取索引搜索对象 IndexSearcher indexSearcher = new IndexSearcher(indexReader); Analyzer analyzer = new StandardAnalyzer(); QueryParser queryParser = new QueryParser("contents", analyzer); // 获取符合关键字的查询对象 Query query = queryParser.parse(q); long start=System.currentTimeMillis(); // 获取关键字出现的前十次 TopDocs topDocs = indexSearcher.search(query , 10); long end=System.currentTimeMillis(); System.out.println("匹配 "+q+" ,总共花费"+(end-start)+"毫秒"+"查询到"+topDocs.totalHits+"个记录"); for (ScoreDoc scoreDoc : topDocs.scoreDocs) { int docID = scoreDoc.doc; // 索引搜索对象通过文档下标获取文档 Document doc = indexSearcher.doc(docID); System.out.println("通过索引文件:"+doc.get("fullPath")+"拿数据"); } indexReader.close(); } }
Dome02.java
/** * 查询索引测试 * @author Administrator * */ public class Demo2 { public static void main(String[] args) { String indexDir = "D:\\lucenetemp\\lucene\\demo1"; String q = "EarlyTerminating-Collector"; try { IndexUse.search(indexDir, q); } catch (Exception e) { e.printStackTrace(); } } }
构建索引
注:大数据时用合并前的删除,知识给索引文件打标,定时清理打标的索引文件。
数据量不是特别大的时候,可以及时删除索引文件。
Dome03.java
/** * 构建索引 * 对索引的增删改 * @author Administrator * */ public class Demo3 { private String ids[]={"1","2","3"}; private String citys[]={"qingdao","nanjing","shanghai"}; private String descs[]={ "Qingdao is a beautiful city.", "Nanjing is a city of culture.", "Shanghai is a bustling city." }; private FSDirectory dir; /** * 每次都生成索引文件 * @throws Exception */ @Before public void setUp() throws Exception { dir = FSDirectory.open(Paths.get("D:\\lucenetemp\\lucene\\demo2\\indexDir")); IndexWriter indexWriter = getIndexWriter(); for (int i = 0; i < ids.length; i++) { Document doc = new Document(); doc.add(new StringField("id", ids[i], Field.Store.YES)); doc.add(new StringField("city", citys[i], Field.Store.YES)); doc.add(new TextField("desc", descs[i], Field.Store.NO)); indexWriter.addDocument(doc); } indexWriter.close(); } /** * 获取索引输出流 * @return * @throws Exception */ private IndexWriter getIndexWriter() throws Exception{ Analyzer analyzer = new StandardAnalyzer(); IndexWriterConfig conf = new IndexWriterConfig(analyzer); return new IndexWriter(dir, conf ); } /** * 测试写了几个索引文件 * @throws Exception */ @Test public void getWriteDocNum() throws Exception { IndexWriter indexWriter = getIndexWriter(); System.out.println("索引目录下生成"+indexWriter.numDocs()+"个索引文件"); } /** * 打上标记,该索引实际并未删除 * @throws Exception */ @Test public void deleteDocBeforeMerge() throws Exception { IndexWriter indexWriter = getIndexWriter(); System.out.println("最大文档数:"+indexWriter.maxDoc()); indexWriter.deleteDocuments(new Term("id", "1")); indexWriter.commit(); System.out.println("最大文档数:"+indexWriter.maxDoc()); System.out.println("实际文档数:"+indexWriter.numDocs()); indexWriter.close(); } /** * 对应索引文件已经删除,但是该版本的分词会保留 * @throws Exception */ @Test public void deleteDocAfterMerge() throws Exception { // https://blog.csdn.net/asdfsadfasdfsa/article/details/78820030 // org.apache.lucene.store.LockObtainFailedException: Lock held by this virtual machine:indexWriter是单例的、线程安全的,不允许打开多个。 IndexWriter indexWriter = getIndexWriter(); System.out.println("最大文档数:"+indexWriter.maxDoc()); indexWriter.deleteDocuments(new Term("id", "1")); indexWriter.forceMergeDeletes(); //强制删除 indexWriter.commit(); System.out.println("最大文档数:"+indexWriter.maxDoc()); System.out.println("实际文档数:"+indexWriter.numDocs()); indexWriter.close(); } /** * 测试更新索引 * @throws Exception */ @Test public void testUpdate()throws Exception{ IndexWriter writer=getIndexWriter(); Document doc=new Document(); doc.add(new StringField("id", "1", Field.Store.YES)); doc.add(new StringField("city","qingdao",Field.Store.YES)); doc.add(new TextField("desc", "dsss is a city.", Field.Store.NO)); writer.updateDocument(new Term("id","1"), doc); writer.close(); } }
合并前:
合并后:
文档域加权
Dome04.java
public class Demo4 { private String ids[]={"1","2","3","4"}; private String authors[]={"Jack","Marry","John","Json"}; private String positions[]={"accounting","technician","salesperson","boss"}; private String titles[]={"Java is a good language.","Java is a cross platform language","Java powerful","You should learn java"}; private String contents[]={ "If possible, use the same JRE major version at both index and search time.", "When upgrading to a different JRE major version, consider re-indexing. ", "Different JRE major versions may implement different versions of Unicode,", "For example: with Java 1.4, `LetterTokenizer` will split around the character U+02C6," }; private Directory dir;//索引文件目录 @Before public void setUp()throws Exception { dir = FSDirectory.open(Paths.get("D:\\lucenetemp\\lucene\\demo3\\indexDir")); IndexWriter writer = getIndexWriter(); for (int i = 0; i < authors.length; i++) { Document doc = new Document(); doc.add(new StringField("id", ids[i], Field.Store.YES)); doc.add(new StringField("author", authors[i], Field.Store.YES)); doc.add(new StringField("position", positions[i], Field.Store.YES)); TextField textField = new TextField("title", titles[i], Field.Store.YES); // Json投钱做广告,把排名刷到第一了 // if("boss".equals(positions[i])) { // textField.setBoost(2f);//设置权重,默认为1 // } doc.add(textField); // TextField会分词,StringField不会分词 doc.add(new TextField("content", contents[i], Field.Store.NO)); writer.addDocument(doc); } writer.close(); } private IndexWriter getIndexWriter() throws Exception{ Analyzer analyzer = new StandardAnalyzer(); IndexWriterConfig conf = new IndexWriterConfig(analyzer); return new IndexWriter(dir, conf); } @Test public void index() throws Exception{ IndexReader reader = DirectoryReader.open(dir); IndexSearcher searcher = new IndexSearcher(reader); String fieldName = "title"; String keyWord = "java"; Term t = new Term(fieldName, keyWord); Query query = new TermQuery(t); TopDocs hits = searcher.search(query, 10); System.out.println("关键字:‘"+keyWord+"’命中了"+hits.totalHits+"次"); for (ScoreDoc scoreDoc : hits.scoreDocs) { Document doc = searcher.doc(scoreDoc.doc); System.out.println(doc.get("author")); } } }
文档加权后
注:文档加权可以提升排名,一般浏览器搜索都是如此,镀金玩家就是牛逼!
索引搜索功能
特定项搜索
Dome05.java
/** * 特定项搜索 * 查询表达式(queryParser) * @author Administrator * */ public class Demo5 { @Before public void setUp() { // 索引文件将要存放的位置 String indexDir = "D:\\lucenetemp\\lucene\\demo4"; // 数据源地址 String dataDir = "D:\\lucenetemp\\lucene\\demo4\\data"; IndexCreate ic = null; try { ic = new IndexCreate(indexDir); long start = System.currentTimeMillis(); int num = ic.index(dataDir); long end = System.currentTimeMillis(); System.out.println("检索指定路径下" + num + "个文件,一共花费了" + (end - start) + "毫秒"); } catch (Exception e) { e.printStackTrace(); } finally { try { ic.closeIndexWriter(); } catch (Exception e) { e.printStackTrace(); } } } /** * 特定项搜索 */ @Test public void testTermQuery() { String indexDir = "D:\\lucenetemp\\lucene\\demo4"; String fld = "contents"; String text = "indexformattoooldexception"; // 特定项片段名和关键字 Term t = new Term(fld , text); TermQuery tq = new TermQuery(t ); try { FSDirectory indexDirectory = FSDirectory.open(Paths.get(indexDir)); // 注意:索引输入流不是new出来的,是通过目录读取工具类打开的 IndexReader indexReader = DirectoryReader.open(indexDirectory); // 获取索引搜索对象 IndexSearcher is = new IndexSearcher(indexReader); TopDocs hits = is.search(tq, 100); // System.out.println(hits.totalHits); for(ScoreDoc scoreDoc: hits.scoreDocs) { Document doc = is.doc(scoreDoc.doc); System.out.println("文件"+doc.get("fullPath")+"中含有该关键字"); } } catch (IOException e) { e.printStackTrace(); } } /** * 查询表达式(queryParser) */ @Test public void testQueryParser() { String indexDir = "D:\\lucenetemp\\lucene\\demo4"; // 获取查询解析器(通过哪种分词器去解析哪种片段) QueryParser queryParser = new QueryParser("contents", new StandardAnalyzer()); try { FSDirectory indexDirectory = FSDirectory.open(Paths.get(indexDir)); // 注意:索引输入流不是new出来的,是通过目录读取工具类打开的 IndexReader indexReader = DirectoryReader.open(indexDirectory); // 获取索引搜索对象 IndexSearcher is = new IndexSearcher(indexReader); // 由解析器去解析对应的关键字 TopDocs hits = is.search(queryParser.parse("indexformattoooldexception") , 100); for(ScoreDoc scoreDoc: hits.scoreDocs) { Document doc = is.doc(scoreDoc.doc); System.out.println("文件"+doc.get("fullPath")+"中含有该关键字"); } } catch (IOException e) { e.printStackTrace(); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } }
查询表达式
@Test public void testQueryParser() { String indexDir = "E:\\temp\\T224\\lucene\\demo4"; // 获取查询解析器(通过哪种分词器去解析哪种片段) QueryParser queryParser = new QueryParser("contents", new StandardAnalyzer()); try { FSDirectory indexDirectory = FSDirectory.open(Paths.get(indexDir)); // 注意:索引输入流不是new出来的,是通过目录读取工具类打开的 IndexReader indexReader = DirectoryReader.open(indexDirectory); // 获取索引搜索对象 IndexSearcher is = new IndexSearcher(indexReader); // 由解析器去解析对应的关键字 TopDocs hits = is.search(queryParser.parse("indexformattoooldexception") , 100); for(ScoreDoc scoreDoc: hits.scoreDocs) { Document doc = is.doc(scoreDoc.doc); System.out.println("文件"+doc.get("fullPath")+"中含有该关键字"); } } catch (IOException e) { e.printStackTrace(); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } }
指定(范围,字母)查询表达式
/** * 指定数字范围查询 * 指定字符串开头字母查询(prefixQuery) * @author Administrator * */ public class Demo6 { private int ids[]={1,2,3}; private String citys[]={"qingdao","nanjing","shanghai"}; private String descs[]={ "Qingdao is a beautiful city.", "Nanjing is a city of culture.", "Shanghai is a bustling city." }; private FSDirectory dir; /** * 每次都生成索引文件 * @throws Exception */ @Before public void setUp() throws Exception { dir = FSDirectory.open(Paths.get("D:\\lucenetemp\\lucene\\demo2\\indexDir")); IndexWriter indexWriter = getIndexWriter(); for (int i = 0; i < ids.length; i++) { Document doc = new Document(); doc.add(new IntField("id", ids[i], Field.Store.YES)); doc.add(new StringField("city", citys[i], Field.Store.YES)); doc.add(new TextField("desc", descs[i], Field.Store.YES)); indexWriter.addDocument(doc); } indexWriter.close(); } /** * 获取索引输出流 * @return * @throws Exception */ private IndexWriter getIndexWriter() throws Exception{ Analyzer analyzer = new StandardAnalyzer(); IndexWriterConfig conf = new IndexWriterConfig(analyzer); return new IndexWriter(dir, conf ); } /** * 指定数字范围查询 * @throws Exception */ @Test public void testNumericRangeQuery()throws Exception{ IndexReader reader = DirectoryReader.open(dir); IndexSearcher is = new IndexSearcher(reader); NumericRangeQuery<Integer> query=NumericRangeQuery.newIntRange("id", 1, 2, true, true); TopDocs hits=is.search(query, 10); for(ScoreDoc scoreDoc:hits.scoreDocs){ Document doc=is.doc(scoreDoc.doc); System.out.println(doc.get("id")); System.out.println(doc.get("city")); System.out.println(doc.get("desc")); } } /** * 指定字符串开头字母查询(prefixQuery) * @throws Exception */ @Test public void testPrefixQuery()throws Exception{ IndexReader reader = DirectoryReader.open(dir); IndexSearcher is = new IndexSearcher(reader); PrefixQuery query=new PrefixQuery(new Term("city","n")); TopDocs hits=is.search(query, 10); for(ScoreDoc scoreDoc:hits.scoreDocs){ Document doc=is.doc(scoreDoc.doc); System.out.println(doc.get("id")); System.out.println(doc.get("city")); System.out.println(doc.get("desc")); } } @Test public void testBooleanQuery()throws Exception{ IndexReader reader = DirectoryReader.open(dir); IndexSearcher is = new IndexSearcher(reader); NumericRangeQuery<Integer> query1=NumericRangeQuery.newIntRange("id", 1, 2, true, true); PrefixQuery query2=new PrefixQuery(new Term("city","n")); BooleanQuery.Builder booleanQuery=new BooleanQuery.Builder(); booleanQuery.add(query1,BooleanClause.Occur.MUST); booleanQuery.add(query2,BooleanClause.Occur.MUST); TopDocs hits=is.search(booleanQuery.build(), 10); for(ScoreDoc scoreDoc:hits.scoreDocs){ Document doc=is.doc(scoreDoc.doc); System.out.println(doc.get("id")); System.out.println(doc.get("city")); System.out.println(doc.get("desc")); } } }
组合查询
效果是其上功能的组合
中文分词&&高亮显示
中文分词
private Integer ids[]={1,2,3}; private String citys[]={"青岛","南京","上海"}; private String descs[]={ "青岛是个美丽的城市。", "南京是个有文化的城市。", "上海市个繁华的城市。" };
把句子分成词,还未达到想要的效果,那么继续
在pom.xml导入依赖
<dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-analyzers-smartcn</artifactId> <version>5.3.1</version> </dependency>
这儿依赖把分词器的标准改成了中文分词器
高亮显示
导入依赖
<dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-highlighter</artifactId> <version>5.3.1</version> </dependency>
高亮显示的步骤:
1、通过查询对象,获取查询得分对象
2、通过得分对象,获取对应的片段
3、实例化一个html格式化对象
4、通过html格式化实例和查询得分实例,来实例化Lucene提供的高亮显示类对象。
5、将前面获取到的得分片段,设置到高亮显示的的实例对象中。
6、通过分词器获取TokenStream令牌流对象
7、通过令牌和原有的片段,去拿高亮展示后的片段
Dome07.java
public class Demo7 { private Integer ids[] = { 1, 2, 3 }; private String citys[] = { "青岛", "南京", "上海" }; // private String descs[]={ // "青岛是个美丽的城市。", // "南京是个有文化的城市。", // "上海市个繁华的城市。" // }; private String descs[] = { "青岛是个美丽的城市。", "南京是一个文化的城市南京,简称宁,是江苏省会,地处中国东部地区,长江下游,濒江近海。全市下辖11个区,总面积6597平方公里,2013年建成区面积752.83平方公里,常住人口818.78万,其中城镇人口659.1万人。[1-4] “江南佳丽地,金陵帝王州”,南京拥有着6000多年文明史、近2600年建城史和近500年的建都史,是中国四大古都之一,有“六朝古都”、“十朝都会”之称,是中华文明的重要发祥地,历史上曾数次庇佑华夏之正朔,长期是中国南方的政治、经济、文化中心,拥有厚重的文化底蕴和丰富的历史遗存。[5-7] 南京是国家重要的科教中心,自古以来就是一座崇文重教的城市,有“天下文枢”、“东南第一学”的美誉。截至2013年,南京有高等院校75所,其中211高校8所,仅次于北京上海;国家重点实验室25所、国家重点学科169个、两院院士83人,均居中国第三。[8-10]", "上海市个繁华的城市。" }; private FSDirectory dir; /** * 每次都生成索引文件 * * @throws Exception */ @Before public void setUp() throws Exception { dir = FSDirectory.open(Paths.get("D:\\lucenetemp\\lucene\\demo2\\indexDir")); IndexWriter indexWriter = getIndexWriter(); for (int i = 0; i < ids.length; i++) { Document doc = new Document(); doc.add(new IntField("id", ids[i], Field.Store.YES)); doc.add(new StringField("city", citys[i], Field.Store.YES)); doc.add(new TextField("desc", descs[i], Field.Store.YES)); indexWriter.addDocument(doc); } indexWriter.close(); } /** * 获取索引输出流 * * @return * @throws Exception */ private IndexWriter getIndexWriter() throws Exception { // Analyzer analyzer = new StandardAnalyzer(); Analyzer analyzer = new SmartChineseAnalyzer(); IndexWriterConfig conf = new IndexWriterConfig(analyzer); return new IndexWriter(dir, conf); } /** * luke查看索引生成 * * @throws Exception */ @Test public void testIndexCreate() throws Exception { } /** * 测试高亮 * * @throws Exception */ @Test public void testHeight() throws Exception { IndexReader reader = DirectoryReader.open(dir); IndexSearcher searcher = new IndexSearcher(reader); SmartChineseAnalyzer analyzer = new SmartChineseAnalyzer(); QueryParser parser = new QueryParser("desc", analyzer); // Query query = parser.parse("南京文化"); Query query = parser.parse("南京文明"); TopDocs hits = searcher.search(query, 100); // 查询得分项 QueryScorer queryScorer = new QueryScorer(query); // 得分项对应的内容片段 SimpleSpanFragmenter fragmenter = new SimpleSpanFragmenter(queryScorer); // 高亮显示的样式 SimpleHTMLFormatter htmlFormatter = new SimpleHTMLFormatter("<span color='red'><b>", "</b></span>"); // 高亮显示对象 Highlighter highlighter = new Highlighter(htmlFormatter, queryScorer); // 设置需要高亮显示对应的内容片段 highlighter.setTextFragmenter(fragmenter); for (ScoreDoc scoreDoc : hits.scoreDocs) { Document doc = searcher.doc(scoreDoc.doc); String desc = doc.get("desc"); if (desc != null) { // tokenstream是从doucment的域(field)中抽取的一个个分词而组成的一个数据流,用于分词。 TokenStream tokenStream = analyzer.tokenStream("desc", new StringReader(desc)); System.out.println("高亮显示的片段:" + highlighter.getBestFragment(tokenStream, desc)); } System.out.println("所有内容:" + desc); } } }
综合案例:
pom.xml(放所有的jar包依赖)
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.javaxl</groupId> <artifactId>javaxl_lunece_freemarker</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>javaxl_lunece_freemarker Maven Webapp</name> <url>http://maven.apache.org</url> <properties> <httpclient.version>4.5.2</httpclient.version> <jsoup.version>1.10.1</jsoup.version> <!-- <lucene.version>7.1.0</lucene.version> --> <lucene.version>5.3.1</lucene.version> <ehcache.version>2.10.3</ehcache.version> <junit.version>4.12</junit.version> <log4j.version>1.2.16</log4j.version> <mysql.version>5.1.44</mysql.version> <fastjson.version>1.2.47</fastjson.version> <struts2.version>2.5.16</struts2.version> <servlet.version>4.0.1</servlet.version> <jstl.version>1.2</jstl.version> <standard.version>1.1.2</standard.version> <tomcat-jsp-api.version>8.0.47</tomcat-jsp-api.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> <scope>test</scope> </dependency> <!-- jdbc驱动包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!-- 添加Httpclient支持 --> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>${httpclient.version}</version> </dependency> <!-- 添加jsoup支持 --> <dependency> <groupId>org.jsoup</groupId> <artifactId>jsoup</artifactId> <version>${jsoup.version}</version> </dependency> <!-- 添加日志支持 --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>${log4j.version}</version> </dependency> <!-- 添加ehcache支持 --> <dependency> <groupId>net.sf.ehcache</groupId> <artifactId>ehcache</artifactId> <version>${ehcache.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>${fastjson.version}</version> </dependency> <dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2-core</artifactId> <version>${struts2.version}</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>${servlet.version}</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-core</artifactId> <version>${lucene.version}</version> </dependency> <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-queryparser</artifactId> <version>${lucene.version}</version> </dependency> <!-- <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-analyzers-common</artifactId> <version>${lucene.version}</version> </dependency> --> <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-analyzers-smartcn</artifactId> <version>${lucene.version}</version> </dependency> <dependency> <groupId>org.apache.lucene</groupId> <artifactId>lucene-highlighter</artifactId> <version>${lucene.version}</version> </dependency> <!-- 5.3、jstl、standard --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>${jstl.version}</version> </dependency> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>${standard.version}</version> </dependency> <!-- 5.4、tomcat-jsp-api --> <dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-jsp-api</artifactId> <version>${tomcat-jsp-api.version}</version> </dependency> </dependencies> <build> <finalName>javaxl_lunece_freemarker</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.7.0</version> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> </plugins> </build> </project>
BlogActio.java
public class BlogAction { private String title; private BlogDao blogDao = new BlogDao(); public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String list() { try { HttpServletRequest request = ServletActionContext.getRequest(); if (StringUtils.isBlank(title)) { List<Map<String, Object>> blogList = this.blogDao.list(title, null); request.setAttribute("blogList", blogList); }else { Directory directory = LuceneUtil.getDirectory(PropertiesUtil.getValue("indexPath")); DirectoryReader reader = LuceneUtil.getDirectoryReader(directory); IndexSearcher searcher = LuceneUtil.getIndexSearcher(reader); SmartChineseAnalyzer analyzer = new SmartChineseAnalyzer(); // 拿一句话到索引目中的索引文件中的词库进行关键词碰撞 Query query = new QueryParser("title", analyzer).parse(title); Highlighter highlighter = LuceneUtil.getHighlighter(query, "title"); TopDocs topDocs = searcher.search(query , 100); //处理得分命中的文档 List<Map<String, Object>> blogList = new ArrayList<>(); Map<String, Object> map = null; ScoreDoc[] scoreDocs = topDocs.scoreDocs; for (ScoreDoc scoreDoc : scoreDocs) { map = new HashMap<>(); Document doc = searcher.doc(scoreDoc.doc); map.put("id", doc.get("id")); String titleHighlighter = doc.get("title"); if(StringUtils.isNotBlank(titleHighlighter)) { titleHighlighter = highlighter.getBestFragment(analyzer, "title", titleHighlighter); } map.put("title", titleHighlighter); map.put("url", doc.get("url")); blogList.add(map); } request.setAttribute("blogList", blogList); } } catch (Exception e) { e.printStackTrace(); } return "blogList"; } }
IndexStarter.java
/** * 构建lucene索引 * @author Administrator * 1。构建索引 IndexWriter * 2、读取索引文件,获取命中片段 * 3、使得命中片段高亮显示 * */ public class IndexStarter { private static BlogDao blogDao = new BlogDao(); public static void main(String[] args) { IndexWriterConfig conf = new IndexWriterConfig(new SmartChineseAnalyzer()); Directory d; IndexWriter indexWriter = null; try { d = FSDirectory.open(Paths.get(PropertiesUtil.getValue("indexPath"))); indexWriter = new IndexWriter(d , conf ); // 为数据库中的所有数据构建索引 List<Map<String, Object>> list = blogDao.list(null, null); for (Map<String, Object> map : list) { Document doc = new Document(); doc.add(new StringField("id", (String) map.get("id"), Field.Store.YES)); // TextField用于对一句话分词处理 java培训机构 doc.add(new TextField("title", (String) map.get("title"), Field.Store.YES)); doc.add(new StringField("url", (String) map.get("url"), Field.Store.YES)); indexWriter.addDocument(doc); } } catch (IOException e) { e.printStackTrace(); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); }finally { try { if(indexWriter!= null) { indexWriter.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }
效果