1.Lucene是什么
Lucene是apache下的一个开源的全文检索引擎工具包。
2.什么是全文检索
全文检索就是先分词创建索引，再执行搜索的过程。
3.什么是分词
就是将一段文字分成一个个单词
4.Lucene实现全文检索的流程
全文检索的流程分为两大部分：索引流程、搜索流程。
索引流程：采集数据--->构建文档对象--->创建索引(将文档写入索引库)。
搜索流程：创建查询--->执行搜索--->渲染搜索结果。
5.代码
5.1项目结构
5.2BookDao代码
1 package cn.hc.dao;
2
3 import cn.hc.pojo.Book;
4 import cn.hc.util.GetConn;
5 import org.apache.lucene.document.*;
6
7 import java.sql.Connection;
8 import java.sql.ResultSet;
9 import java.sql.SQLException;
10 import java.sql.Statement;
11 import java.util.ArrayList;
12 import java.util.List;
13
14 public class BookDao {
15
16 public List<Book> queryAll(){
17 /*
18 1.获得连接
19 2.获得操作对象
20 3.执行sql语句
21 4.关闭
22 * */
23 Connection conn = GetConn.getConn();
24 try {
25 Statement statement = conn.createStatement();
26 ResultSet resultSet = statement.executeQuery("select * from book;");
27 List<Book> books=new ArrayList<>();
28 while(resultSet.next()){
29 Book book = new Book();
30 book.setId(resultSet.getInt("id"));
31 book.setDescription(resultSet.getString("description"));
32 book.setPic(resultSet.getString("pic"));
33 book.setPrice(resultSet.getFloat("price"));
34 book.setName(resultSet.getString("name"));
35 books.add(book);
36 }
37 return books;
38 } catch (SQLException e) {
39 e.printStackTrace();
40 return null;
41 }
42
43 }
44
45 public List<Document> getDocuments(List<Book> books){
46 List<Document> documents = new ArrayList<>();
47 for (Book book : books) {
48 Document document = new Document();
49 Field id = new StoredField("id",book.getId().toString());
50 Field name = new TextField("name", book.getName(), Field.Store.YES);
51 Field price = new FloatField("price",book.getPrice(), Field.Store.YES);
52 Field pic = new StoredField("pic", book.getPic());
53 Field description = new TextField("description", book.getDescription(), Field.Store.NO);
54 document.add(id);
55 document.add(name);
56 document.add(pic);
57 document.add(price);
58 document.add(description);
59 documents.add(document);
60 }
61 return documents;
62 }
63
64
65 }
5.3 pojo包Book代码
1 package cn.hc.pojo;
2
3 public class Book {
4 private Integer id;//int (11),
5 private String name;//varchar (192),
6 private Float price;//float ,
7 private String pic;//varchar (96),
8 private String description;//text
9
10 public Integer getId() {
11 return id;
12 }
13
14 public void setId(Integer id) {
15 this.id = id;
16 }
17
18 public String getName() {
19 return name;
20 }
21
22 public void setName(String name) {
23 this.name = name;
24 }
25
26 public Float getPrice() {
27 return price;
28 }
29
30 public void setPrice(Float price) {
31 this.price = price;
32 }
33
34 public String getPic() {
35 return pic;
36 }
37
38 public void setPic(String pic) {
39 this.pic = pic;
40 }
41
42 public String getDescription() {
43 return description;
44 }
45
46 public void setDescription(String description) {
47 this.description = description;
48 }
49
50 @Override
51 public String toString() {
52 return "Book{" +
53 "id=" + id +
54 ", name='" + name + '\'' +
55 ", price=" + price +
56 ", pic='" + pic + '\'' +
57 ", description='" + description + '\'' +
58 '}';
59 }
60 }
5.4 util包GetConn
1 package cn.hc.util;
2
3
4 import com.mysql.cj.jdbc.Driver;
5
6 import java.sql.Connection;
7 import java.sql.DriverManager;
8
9 public class GetConn {
10
11 public static Connection getConn() {
12 // 连接4要素
13 //1.驱动
14 String driver = "com.mysql.cj.jdbc.Driver";
15 //2.url
16 String url = "jdbc:mysql://localhost:3307/lucene?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT";
17 // 3.username
18 String username = "root";
19 //4.pwd
20 String password = "root";
21
22 try {
23 Class.forName(driver);
24 /* Driver driver =new Driver();
25 DriverManager.registerDriver(driver);*/
26 Connection connection = DriverManager.getConnection(url, username, password);
27 return connection;
28 } catch (Exception e) {
29 e.printStackTrace();
30 } finally {
31 }
32
33 return null;
34 }
35
36
37 }
5.5 util包DoSearch方法
1 package cn.hc.util;
2
3 import org.apache.lucene.analysis.standard.StandardAnalyzer;
4 import org.apache.lucene.document.Document;
5 import org.apache.lucene.index.DirectoryReader;
6 import org.apache.lucene.index.IndexReader;
7 import org.apache.lucene.queryparser.classic.ParseException;
8 import org.apache.lucene.queryparser.classic.QueryParser;
9 import org.apache.lucene.search.IndexSearcher;
10 import org.apache.lucene.search.Query;
11 import org.apache.lucene.search.ScoreDoc;
12 import org.apache.lucene.search.TopDocs;
13 import org.apache.lucene.store.FSDirectory;
14
15 import java.io.File;
16
17 public class DoSearch {
18
19 public static void doSearch(Query query) throws Exception {
20 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
21 IndexReader reader = DirectoryReader.open(directory);
22 IndexSearcher searcher = new IndexSearcher(reader);
23 TopDocs topDocs = searcher.search(query, 10);
24 ScoreDoc[] scoreDocs = topDocs.scoreDocs;
25 for (ScoreDoc scoreDoc : scoreDocs) {
26 //document 的id
27 int documentId = scoreDoc.doc;
28 Document document = searcher.doc(documentId);
29 System.out.println("编号:"+document.get("id")+",书名："+document.get("name"));
30
31 }
32 reader.close();
33 }
34 }
5.6 test包代码
1 package cn.hc.test;
2
3 import cn.hc.dao.BookDao;
4 import cn.hc.pojo.Book;
5 import cn.hc.util.DoSearch;
6 import cn.hc.util.GetConn;
7 import org.apache.lucene.analysis.standard.StandardAnalyzer;
8 import org.apache.lucene.document.Document;
9 import org.apache.lucene.document.Field;
10 import org.apache.lucene.document.TextField;
11 import org.apache.lucene.index.*;
12 import org.apache.lucene.queryparser.classic.ParseException;
13 import org.apache.lucene.queryparser.classic.QueryParser;
14 import org.apache.lucene.search.*;
15 import org.apache.lucene.store.FSDirectory;
16 import org.apache.lucene.util.Version;
17 import org.junit.Test;
18 import org.wltea.analyzer.lucene.IKAnalyzer;
19
20
21 import java.io.File;
22 import java.io.IOException;
23 import java.sql.Connection;
24 import java.sql.ResultSet;
25 import java.sql.SQLException;
26 import java.sql.Statement;
27 import java.util.ArrayList;
28 import java.util.List;
29
30 public class SimpleTest {
31
32 @Test
33 public void queryAll(){
34 /*
35 1.获得连接
36 2.获得操作对象
37 3.执行sql语句
38 4.关闭
39 * */
40 Connection conn = GetConn.getConn();
41 try {
42 Statement statement = conn.createStatement();
43 ResultSet resultSet = statement.executeQuery("select * from book;");
44 List<Book> books=new ArrayList<>();
45 while(resultSet.next()){
46 Book book = new Book();
47 book.setId(resultSet.getInt("id"));
48 book.setDescription(resultSet.getString("description"));
49 book.setPic(resultSet.getString("pic"));
50 book.setPrice(resultSet.getFloat("price"));
51 book.setName(resultSet.getString("name"));
52 books.add(book);
53 }
54 for (Book book : books) {
55 System.out.println(book.getName());
56 }
57
58 } catch (SQLException e) {
59 e.printStackTrace();
60
61 }
62
63 }
64 // 创建索引库
65 @Test
66 public void createIndex(){
67 BookDao bookDao = new BookDao();
68 //创建分词解析器
69 StandardAnalyzer analyzer = new StandardAnalyzer();
70 try {
71 //打开解析文档
72 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
73 //配置分词解析文件
74 IndexWriterConfig config = new IndexWriterConfig(Version.LATEST, analyzer);
75 //创建索引写入对象
76 IndexWriter writer = new IndexWriter(directory, config);
77 //添加document索引
78 writer.addDocuments(bookDao.getDocuments(bookDao.queryAll()));
79 writer.close();
80 System.out.println("创建索引库成功");
81 } catch (IOException e) {
82 e.printStackTrace();
83 }
84
85
86 }
87 // 通过docId查询document
88 @Test
89 public void searchDocumentByIndex() throws Exception {
90 //创建解析方法
91 StandardAnalyzer analyzer = new StandardAnalyzer();
92 //创建查询解析器
93 QueryParser queryParser = new QueryParser("name", analyzer);
94 //创建查询条件对象
95 Query query = queryParser.parse("name:python python");
96 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
97 //创建索引读取对象
98 IndexReader reader = DirectoryReader.open(directory);
99 //创建搜索器
100 IndexSearcher searcher = new IndexSearcher(reader);
101 TopDocs topDocs = searcher.search(query, 10);
102 ScoreDoc[] scoreDocs = topDocs.scoreDocs;
103 for (ScoreDoc scoreDoc : scoreDocs) {
104 //document 的id
105 int documentId = scoreDoc.doc;
106 Document document = searcher.doc(documentId);
107 System.out.println("编号:"+document.get("id")+",书名："+document.get("name"));
108
109
110 }
111 reader.close();
112
113 }
114
115 //删除索引和文档
116 @Test
117 public void deleteIndex() throws IOException {
118 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
119 IndexWriterConfig config = new IndexWriterConfig(Version.LATEST, new StandardAnalyzer());
120 IndexWriter writer = new IndexWriter(directory, config);
121 writer.deleteDocuments(new Term("name","java"));
122 writer.close();
123 }
124 //删除所有
125 @Test
126 public void deleteAll() throws IOException {
127 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
128 IndexWriterConfig config = new IndexWriterConfig(Version.LATEST, new StandardAnalyzer());
129 IndexWriter writer = new IndexWriter(directory, config);
130 writer.deleteAll();
131 writer.close();
132 }
133 //更新document
134 @Test
135 public void updateDocument() throws IOException {
136 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
137 IndexWriterConfig config = new IndexWriterConfig(Version.LATEST, new StandardAnalyzer());
138 IndexWriter writer = new IndexWriter(directory, config);
139 Document document = new Document();
140 Field field = new TextField("name", "python is good", Field.Store.YES);
141 document.add(field);
142 writer.updateDocument(new Term("name","java"),document);
143 writer.close();
144 }
145 //精确查询 TermQuery
146 @Test
147 public void queryByTermQuery() throws Exception {
148 Query query = new TermQuery(new Term("name", "编程思想"));
149 DoSearch.doSearch(query);
150 }
151
152 //数字范围查询 NumericRangeQuery
153 @Test
154 public void queryByNumericRangeQuery() throws Exception {
155 Query query = NumericRangeQuery.newFloatRange("price", 60.0f, 80.0f, true, false);
156 DoSearch.doSearch(query);
157 }
158 //条件查询 BooleanQuery
159 @Test
160 public void queryByBooleanQuery() throws Exception {
161 Query price = NumericRangeQuery.newFloatRange("price", 60.0f, 80.0f, true, false);
162 Query name = new TermQuery(new Term("name", "solr"));
163 BooleanQuery query = new BooleanQuery();
164 query.add(price, BooleanClause.Occur.MUST);//必须满足条件
165 query.add(name, BooleanClause.Occur.MUST_NOT);//限制条件，query没有值时无效，过滤
166 DoSearch.doSearch(query);
167 }
168 //使用中文分词器IKAnalyzer分词
169 @Test
170 public void createIndexByIKanalyzer() throws IOException {
171 BookDao bookDao = new BookDao();
172 IKAnalyzer ikAnalyzer = new IKAnalyzer();
173 FSDirectory directory = FSDirectory.open(new File("D:\\lucene"));
174 IndexWriterConfig config = new IndexWriterConfig(Version.LATEST, ikAnalyzer);
175 IndexWriter writer = new IndexWriter(directory, config);
176 writer.addDocuments(bookDao.getDocuments(bookDao.queryAll()));
177 writer.close();
178 }
179
180 }