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Luceneapidocument

Documents: Document object, which is an original data

Document Number	Document Content
1	The father of Google Maps job-hopping Facebook
2	The father of Google Maps joins Facebook
3	Google Maps founder Russ leaves Google to join Facebook
4	Google Maps father-to-be Facebook and wave project cancellation related
5	Google Maps father Lars joins social networking site Facebook

= = A record is a document,document each field is a field==

Field

Create an index

  Private final static file Index_file = new file ("E:\\developtools\\indexdir");p ublic static void Indexcreate ( Document DOC) throws Exception {//Create directory object, specify the location of the index library; fsdirectory file system; ramdirectory Memory Directory dir = Fsdirectory.ope    N (index_file);    To create a word breaker Object Analyzer Analyzer = new Ikanalyzer (); Create an index writer configuration object, first parameter version version.latest, second parameter word breaker indexwriterconfig conf = new Indexwriterconfig (version.latest, analyzer    );    Create an index writer IndexWriter indexwriter = new IndexWriter (dir, conf);    Writes a Document Object Indexwriter.adddocument (DOC) to the index library;    Submit Indexwriter.commit (); Close Indexwriter.close ();}  

@Testpublic void createTest() throws Exception {    //    Document doc = new Document();    doc.add(new LongField("id", 1, Store.YES));    doc.add(new TextField("title", "谷歌地图之父跳槽FaceBook", Store.YES));    doc.add(new TextField("context", "据国外媒体报道，曾先后负责谷歌地图和Wave开发工作的拉斯·拉斯姆森(Lars Rasmussen)已经离开谷歌，并将加盟Facebook。", Store.YES));    indexCreate(doc);}

Query index

public static void Indexsearcher (query query, Integer N) throws IOException {//Initialize index library object Directory dir = Fsdirector    Y.open (Index_file);    Index reading tool Indexreader Indexreader = Directoryreader.open (dir);       Index Search Object Indexsearcher indexseracher = new Indexsearcher (Indexreader);    Performs a search operation that returns a value of Topdocs topdocs topdocs = indexseracher.search (query, n);    The total number of records matching the search criteria System.out.println ("Altogether hit:" + topdocs.totalhits + "bar data");    Get the score document array object, score Document object contains score and document number scoredoc[] Scoredocs = Topdocs.scoredocs;        for (Scoredoc scoredoc:scoredocs) {int docID = Scoredoc.doc;        FLOAT score = Scoredoc.score;        SYSTEM.OUT.PRINTLN ("Document number:" + DocID);        System.out.println ("Document score:" + score);        Gets the document object, reading the tool through the index. Document document = Indexreader.document (DocID);        SYSTEM.OUT.PRINTLN ("ID:" + document.get ("id"));        System.out.println ("title:" + document.get ("title"));   SYSTEM.OUT.PRINTLN ("Context:" + document.get ("context")); } indexreader.close ();} 

@Testpublic void searchTest() throws Exception {    //单一字段的查询解析器    // 创建查询解析器对象    QueryParser parser = new QueryParser("title", new IKAnalyzer());    // 创建查询对象    Query query = parser.parse("谷歌");    //根据Query搜索，返回评分最高的n条记录    indexSearcher(query, 10);        /*多字段的查询解析器    MultiFieldQueryParser parser = new MultiFieldQueryParser(new String[]{"id","title"}, new IKAnalyzer());    Query query = parser.parse("1");*/}

Various other query methods

//词条查询，查询条件必须是最小粒度不可再分割的内容Query query = new TermQuery(new Term("title", "谷歌"));//通配符查询, ?：匹配一个字符, *：匹配多个字符Query query = new WildcardQuery(new Term("title", "*歌*"));//模糊查询, 参数：1-词条，查询字段及关键词，关键词允许写错；2-允许写错的最大编辑距离，并且不能大于2（0~2）Query query = new FuzzyQuery(new Term("title", "facebool"), 1);//数值范围查询,查询非String类型的数据或者说是一些继承Numeric类的对象的查询,参数1-字段；2-最小值；3-最大值；4-是否包含最小值；5-是否包含最大值Query query = NumericRangeQuery.newLongRange("id", 2l, 4l, true, true);//组合查询， 交集： Occur.MUST + Occur.MUST, 并集：Occur.SHOULD + Occur.SHOULD, 非：Occur.MUST_NOTBooleanQuery query = new BooleanQuery();Query query1 = NumericRangeQuery.newLongRange("id", 2l, 4l, true, true);Query query2 = new WildcardQuery(new Term("title", "*歌*"));query.add(query1, Occur.SHOULD);query.add(query2, Occur.SHOULD);

modifying indexes

//本质先删除再添加，先删除所有满足条件的文档，再创建文档， 因此，修改索引通常要根据唯一字段public static void indexUpdate(Term term, Document doc) throws IOException {    Directory dir = FSDirectory.open(INDEX_FILE);    Analyzer analyzer = new IKAnalyzer();    IndexWriterConfig conf = new IndexWriterConfig(Version.LATEST, analyzer);    IndexWriter indexWriter = new IndexWriter(dir, conf);    indexWriter.updateDocument(term, doc);    indexWriter.commit();    indexWriter.close();    }

@Testpublic void updateTest() throws Exception {    Term term = new Term("title", "facebook");    Document doc = new Document();    doc.add(new LongField("id", 1L, Store.YES));    doc.add(new TextField("title", "谷歌地图之父跳槽FaceBook", Store.YES));    doc.add(new TextField("context", "河马程序员加盟FaceBook", Store.YES));    indexUpdate(term, doc);}

Delete Index

// 执行删除操作(根据词条)，要求id字段必须是字符串类型public static void indexDelete(Term term) throws IOException {    Directory dir = FSDirectory.open(INDEX_FILE);    Analyzer analyzer = new IKAnalyzer();    IndexWriterConfig conf = new IndexWriterConfig(Version.LATEST, analyzer);    IndexWriter indexWriter = new IndexWriter(dir, conf);    indexWriter.deleteDocuments(term);    indexWriter.commit();    indexWriter.close();    }public static void indexDeleteAll() throws IOException {    Directory dir = FSDirectory.open(INDEX_FILE);    Analyzer analyzer = new IKAnalyzer();    IndexWriterConfig conf = new IndexWriterConfig(Version.LATEST, analyzer);    IndexWriter indexWriter = new IndexWriter(dir, conf);    indexWriter.deleteAll();    indexWriter.commit();    indexWriter.close();    }

@Testpublic void deleteTest() throws Exception {    /*     * Term term = new Term("context", "facebook"); indexDelete(term);     */    indexDeleteAll();}

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