Lucene CREATE Index

Lucene CREATE Index

To add and revise the indexed document

Copy maven dependencies

http://mvnrepository.com/

<dependencies>    <dependency>        <groupId>junit</groupId>        <artifactId>junit</artifactId>        <version>4.12</version>    </dependency></dependencies>

1 Creating an Index

Indexingtest.java

Package Com.matrix.lucene;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.stringfield;import Org.apache.lucene.document.textfield;import Org.apache.lucene.index.indexwriter;import Org.apache.lucene.index.indexwriterconfig;import Org.apache.lucene.store.directory;import    Org.apache.lucene.store.fsdirectory;import Org.junit.before;import Org.junit.test;public class IndexingTest {//test data    Private String ids[] = {"1", "2", "3"};    Private String citys[] = {"Qingdao", "Nanjing", "Shanghai"}; Private String descs[] = {"Qingdao is a beautiful city.", "Nanjing are a city of culture", "Shanghai is a Bustl    ing City "};    Private Directory dir;         @Before public void SetUp () throws Exception {dir = Fsdirectory.open (Paths.get ("E:\\software\\lucene\\demo2")); InchDexwriter writer = getwriter ();            Traverse array for (int i = 0; i < ids.length; i++) {Document doc = new document ();            Storage, can improve efficiency, with space for Time Doc.add (new Stringfield ("id", Ids[i], Field.Store.YES));            Doc.add (New Stringfield ("City", Citys[i], Field.Store.YES));            Store content many times with TextField Doc.add (new TextField ("desc", Descs[i], Field.Store.NO));            Add document Operation Writer.adddocument (DOC);    Write when there is cache in memory}//close Writer.close (); }/** * Description: Get IndexWriter Instance <BR> * Method Name:getwriter<br> * Creator: Matrix <BR> * Time: 2016 April 26-Morning 1:51:47 <BR> * * @return * @throws Exception * indexwriter<br> * @ex Ception <BR> * @see * @since 1.0.0 * * Private IndexWriter getwriter () throws Exception {//Create        Standard Word breaker Analyzer Analyzer = new StandardAnalyzer (); Config, incoming parser instance//To beWhen the index is written to a file in the data source directory, it needs to parse/analyze indexwriterconfig IWC = new Indexwriterconfig (analyzer);        IndexWriter writer = new IndexWriter (dir, IWC);    return writer; }/** * Description: Test wrote several documents <BR> * Method name:testindexwriter<br> * Creator: Matrix <BR> * Time: 2016     April 26-Morning 2:08:05 <BR> * * @throws Exception * void<br> * @exception <BR>  * @see * @since 1.0.0 * */@Test public void Testindexwriter () throws Exception {IndexWriter writer =        Getwriter ();        System.out.println ("Write" + writer.numdocs () + "documents");    Writer.close (); }}

E:\software\lucene\demo2

1.1 Using the Luke tool to view the index

Prerequisite: Install JDK1.8, and configure environment variables

2 reading a document

@Testpublic void testIndexReader() throws Exception {    IndexReader reader = DirectoryReader.open(dir);    System.out.println("最大文档数：" + reader.maxDoc());    System.out.println("实际文档数：" + reader.numDocs());    reader.close();}

3 Deleting a document before merging

// 第一种方式：不合并索引，删除文档，索引不动，只是做标记// 第二种方式：@Testpublic void testDeleteBeforeMerge() throws Exception {    IndexWriter writer = getWriter();    System.out.println("删除前：" + writer.numDocs());    writer.deleteDocuments(new Term("id", "1"));    writer.commit();    System.out.println("删除后：最大文档数即writer.maxDoc()" + writer.maxDoc());    System.out.println("删除后：实际文档数即writer.numDocs()" + writer.numDocs());    writer.close();}

4 Deleting a document after merging

@Testpublic void testDeleteAfterMerge() throws Exception {    IndexWriter writer = getWriter();    System.out.println("删除前："+writer.numDocs());    writer.deleteDocuments(new Term("id","1"));    // 强制删除    writer.forceMergeDeletes();    writer.commit();    System.out.println("writer.maxDocs()："+writer.maxDoc());    System.out.println("writer.numDocs()："+writer.numDocs());    writer.close();}

Use the tool to see if the index is deleted

5 Test Updates

@Testpublic void testUpdate() throws Exception {    IndexWriter writer = getWriter();    // 进行更新操作    Document doc = new Document();    doc.add(new StringField("id", "1", Field.Store.YES));    doc.add(new StringField("city", "shenzhen", Field.Store.YES));    doc.add(new TextField("city", "shenzhen is a great city", Field.Store.NO));    writer.updateDocument(new Term("id", "1"), doc);    writer.close(); }

6 document Field weighting

加权之后，搜索排名会提高

Build Index

@Testpublic void index() throws Exception {    // 打开索引目录,该目录存放创建的索引文件    dir = FSDirectory.open(Paths.get("E:\\software\\lucene\\demo3"));    IndexWriter writer = getWriter();    // 遍历数组    for (int i = 0; i < ids.length; i++) {        Document doc = new Document();        // 存储的话，能提高效率，用空间换时间        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));        // 使用StringField字段则不会进行分词        doc.add(new TextField("title", titles[i], Field.Store.YES));        // 存储内容很多的时候用TextField        doc.add(new TextField("content", contents[i], Field.Store.NO));        // 添加文档        writer.addDocument(doc);        // 写的时候在内存中有缓存    }    // 关闭    writer.close();}

Inquire

@Testpublic void search() throws Exception {    dir = FSDirectory.open(Paths.get("E:\\software\\lucene\\demo3"));    IndexReader reader = DirectoryReader.open(dir);    IndexSearcher is = new IndexSearcher(reader);    // 定义要查询的字段    String seachField = "title";    // 定义要查询的值    String q = "java";    Term t = new Term(seachField, q);    Query query = new TermQuery(t);    TopDocs hits = is.search(query, 10);    System.out.println("匹配‘" + q + "‘，总共查询到" + hits.totalHits + "个文档");    // 遍历TopDocs    for (ScoreDoc scoreDoc : hits.scoreDocs) {        Document doc = is.doc(scoreDoc.doc);        System.out.println("document：" + doc.get("author"));    }    reader.close();}

Weighted operations

Indexingtext2.java

Package Com.matrix.lucene;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.stringfield;import Org.apache.lucene.document.textfield;import Org.apache.lucene.index.directoryreader;import Org.apache.lucene.index.indexreader;import Org.apache.lucene.index.indexwriter;import Org.apache.lucene.index.indexwriterconfig;import Org.apache.lucene.index.term;import Org.apache.lucene.search.indexsearcher;import Org.apache.lucene.search.query;import Org.apache.lucene.search.scoredoc;import Org.apache.lucene.search.termquery;import Org.apache.lucene.search.topdocs;import Org.apache.lucene.store.directory;import Org.apache.lucene.store.fsdirectory;import Org.junit.test;public class IndexingText2 {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 was 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.", "Wh En upgrading to a different JRE major version, consider re-indexing. "," Different JRE major versions may implement Different versions of Unicode, "," for Example:with J    Ava 1.4, ' Lettertokenizer ' would split around the character u+02c6, "};    Private Directory dir;  Get IndexWriter instance//Indexdir: Write index to index directory (this directory holds the index file created) go to public indexwriter getwriter () throws Exception {//        Create a standard word breaker analyzer Analyzer = new StandardAnalyzer ();        Configuration, incoming parser instance//to write an index to a file in the data source directory you need to parse/analyze indexwriterconfig WC = new Indexwriterconfig (analyzer); IndexWriter writer = new IndexWriter (dir, WC);    return writer; }//Generate index @Test public void Index () throws Exception {//Open index directory, which holds the index file created dir = Fsdirectory.ope        N (Paths.get ("E:\\software\\lucene\\demo3"));        IndexWriter writer = getwriter ();            Traverse array for (int i = 0; i < ids.length; i++) {Document doc = new document ();            Storage, can improve efficiency, with space for Time 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));            Using the Stringfield field does not make a word breaker TextField field = new TextField ("title", Titles[i], Field.Store.YES);            Weighted action if ("Boss". Equals (Positions[i])) {field.setboost (1.5f);            } doc.add (field);            Store content in a lot of time with TextField Doc.add (new TextField ("content", Contents[i], Field.Store.NO)); Add a document           Writer.adddocument (DOC);    Write when there is cache in memory}//close Writer.close (); }//Query @Test public void Search () throws Exception {dir = Fsdirectory.open (Paths.get ("E:\\software\\luce        Ne\\demo3 "));        Indexreader reader = Directoryreader.open (dir);        Indexsearcher is = new Indexsearcher (reader);        Defines the field to query String Seachfield = "title";        Defines the value to query String q = "Java";        Term T = new term (Seachfield, q);        Query query = new Termquery (t);        Topdocs hits = is.search (query, 10);        System.out.println ("match" + q + "', a total of query to" + hits.totalhits + "documents");            Traverse Topdocs for (Scoredoc scoreDoc:hits.scoreDocs) {Document doc = Is.doc (scoredoc.doc);        System.out.println ("Document:" + doc.get ("author"));    } reader.close (); public static void Main (string[] args) {}}

Json在最前面是因为权值变高了

Lucene CREATE Index