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Lucene全文检索的【增、删、改、查】 实例详解编程语言

• 编程笔记

　　创建索引

Lucene在进行创建索引时，根据前面一篇博客，已经讲完了大体的流程，这里再简单说下：

Directory directory = FSDirectory.open("/tmp/testindex"); 
IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_CURRENT, analyzer); 
IndexWriter iwriter = new IndexWriter(directory, config); 
Document doc = new Document(); 
String text = "This is the text to be indexed."; 
doc.add(new Field("fieldname", text, TextField.TYPE_STORED)); iwriter.close();

　　1 创建Directory，获取索引目录

　　2 创建词法分析器，创建IndexWriter对象

　　3 创建document对象，存储数据

　　4 关闭IndexWriter，提交

/** 
     * 建立索引 
     *  
     * @param args 
     */ 
    public static void index() throws Exception { 
         
        String text1 = "hello,man!"; 
        String text2 = "goodbye,man!"; 
        String text3 = "hello,woman!"; 
        String text4 = "goodbye,woman!"; 
         
        Date date1 = new Date(); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
 
        IndexWriterConfig config = new IndexWriterConfig( 
                Version.LUCENE_CURRENT, analyzer); 
        indexWriter = new IndexWriter(directory, config); 
 
        Document doc1 = new Document(); 
        doc1.add(new TextField("filename", "text1", Store.YES)); 
        doc1.add(new TextField("content", text1, Store.YES)); 
        indexWriter.addDocument(doc1); 
         
        Document doc2 = new Document(); 
        doc2.add(new TextField("filename", "text2", Store.YES)); 
        doc2.add(new TextField("content", text2, Store.YES)); 
        indexWriter.addDocument(doc2); 
         
        Document doc3 = new Document(); 
        doc3.add(new TextField("filename", "text3", Store.YES)); 
        doc3.add(new TextField("content", text3, Store.YES)); 
        indexWriter.addDocument(doc3); 
         
        Document doc4 = new Document(); 
        doc4.add(new TextField("filename", "text4", Store.YES)); 
        doc4.add(new TextField("content", text4, Store.YES)); 
        indexWriter.addDocument(doc4); 
         
        indexWriter.commit(); 
        indexWriter.close(); 
 
        Date date2 = new Date(); 
        System.out.println("创建索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    }

　　增量添加索引

Lucene拥有增量添加索引的功能，在不会影响之前的索引情况下，添加索引，它会在何时的时机，自动合并索引文件。

/** 
     * 增加索引 
     *  
     * @throws Exception 
     */ 
    public static void insert() throws Exception { 
        String text5 = "hello,goodbye,man,woman"; 
        Date date1 = new Date(); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
 
        IndexWriterConfig config = new IndexWriterConfig( 
                Version.LUCENE_CURRENT, analyzer); 
        indexWriter = new IndexWriter(directory, config); 
 
        Document doc1 = new Document(); 
        doc1.add(new TextField("filename", "text5", Store.YES)); 
        doc1.add(new TextField("content", text5, Store.YES)); 
        indexWriter.addDocument(doc1); 
 
        indexWriter.commit(); 
        indexWriter.close(); 
 
        Date date2 = new Date(); 
        System.out.println("增加索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    }

　　删除索引

Lucene也是通过IndexWriter调用它的delete方法，来删除索引。我们可以通过关键字，删除与这个关键字有关的所有内容。如果仅仅是想要删除一个文档，那么最好就顶一个唯一的ID域，通过这个ID域，来进行删除操作。

/** 
     * 删除索引 
     *  
     * @param str 删除的关键字 
     * @throws Exception 
     */ 
    public static void delete(String str) throws Exception { 
        Date date1 = new Date(); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
 
        IndexWriterConfig config = new IndexWriterConfig( 
                Version.LUCENE_CURRENT, analyzer); 
        indexWriter = new IndexWriter(directory, config); 
         
        indexWriter.deleteDocuments(new Term("filename",str));   
         
        indexWriter.close(); 
         
        Date date2 = new Date(); 
        System.out.println("删除索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    }

　　更新索引

Lucene没有真正的更新操作，通过某个fieldname，可以更新这个域对应的索引，但是实质上，它是先删除索引，再重新建立的。

/** 
     * 更新索引 
     *  
     * @throws Exception 
     */ 
    public static void update() throws Exception { 
        String text1 = "update,hello,man!"; 
        Date date1 = new Date(); 
         analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
         directory = FSDirectory.open(new File(INDEX_DIR)); 
 
         IndexWriterConfig config = new IndexWriterConfig( 
                 Version.LUCENE_CURRENT, analyzer); 
         indexWriter = new IndexWriter(directory, config); 
          
         Document doc1 = new Document(); 
        doc1.add(new TextField("filename", "text1", Store.YES)); 
        doc1.add(new TextField("content", text1, Store.YES)); 
         
        indexWriter.updateDocument(new Term("filename","text1"), doc1); 
         
         indexWriter.close(); 
          
         Date date2 = new Date(); 
         System.out.println("更新索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    }

　　通过索引查询关键字

Lucene的查询方式有很多种，这里就不做详细介绍了。它会返回一个ScoreDoc的集合，类似ResultSet的集合，我们可以通过域名获取想要获取的内容。

/** 
     * 关键字查询 
     *  
     * @param str 
     * @throws Exception 
     */ 
    public static void search(String str) throws Exception { 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        DirectoryReader ireader = DirectoryReader.open(directory); 
        IndexSearcher isearcher = new IndexSearcher(ireader); 
 
        QueryParser parser = new QueryParser(Version.LUCENE_CURRENT, "content",analyzer); 
        Query query = parser.parse(str); 
 
        ScoreDoc[] hits = isearcher.search(query, null, 1000).scoreDocs; 
        for (int i = 0; i < hits.length; i++) { 
            Document hitDoc = isearcher.doc(hits[i].doc); 
            System.out.println(hitDoc.get("filename")); 
            System.out.println(hitDoc.get("content")); 
        } 
        ireader.close(); 
        directory.close(); 
    }

　　全部代码

package test; 
 
import java.io.File; 
import java.util.Date; 
import java.util.List; 
 
import org.apache.lucene.analysis.Analyzer; 
import org.apache.lucene.analysis.standard.StandardAnalyzer; 
import org.apache.lucene.document.Document; 
import org.apache.lucene.document.LongField; 
import org.apache.lucene.document.TextField; 
import org.apache.lucene.document.Field.Store; 
import org.apache.lucene.index.DirectoryReader; 
import org.apache.lucene.index.IndexWriter; 
import org.apache.lucene.index.IndexWriterConfig; 
import org.apache.lucene.index.Term; 
import org.apache.lucene.queryparser.classic.QueryParser; 
import org.apache.lucene.search.IndexSearcher; 
import org.apache.lucene.search.Query; 
import org.apache.lucene.search.ScoreDoc; 
import org.apache.lucene.store.Directory; 
import org.apache.lucene.store.FSDirectory; 
import org.apache.lucene.util.Version; 
 
public class TestLucene { 
    // 保存路径 
    private static String INDEX_DIR = "D://luceneIndex"; 
    private static Analyzer analyzer = null; 
    private static Directory directory = null; 
    private static IndexWriter indexWriter = null; 
 
    public static void main(String[] args) { 
        try { 
//            index(); 
            search("man"); 
//            insert(); 
//            delete("text5"); 
//            update(); 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 
    /** 
     * 更新索引 
     *  
     * @throws Exception 
     */ 
    public static void update() throws Exception { 
        String text1 = "update,hello,man!"; 
        Date date1 = new Date(); 
         analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
         directory = FSDirectory.open(new File(INDEX_DIR)); 
 
         IndexWriterConfig config = new IndexWriterConfig( 
                 Version.LUCENE_CURRENT, analyzer); 
         indexWriter = new IndexWriter(directory, config); 
          
         Document doc1 = new Document(); 
        doc1.add(new TextField("filename", "text1", Store.YES)); 
        doc1.add(new TextField("content", text1, Store.YES)); 
         
        indexWriter.updateDocument(new Term("filename","text1"), doc1); 
         
         indexWriter.close(); 
          
         Date date2 = new Date(); 
         System.out.println("更新索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    } 
    /** 
     * 删除索引 
     *  
     * @param str 删除的关键字 
     * @throws Exception 
     */ 
    public static void delete(String str) throws Exception { 
        Date date1 = new Date(); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
 
        IndexWriterConfig config = new IndexWriterConfig( 
                Version.LUCENE_CURRENT, analyzer); 
        indexWriter = new IndexWriter(directory, config); 
         
        indexWriter.deleteDocuments(new Term("filename",str));   
         
        indexWriter.close(); 
         
        Date date2 = new Date(); 
        System.out.println("删除索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    } 
    /** 
     * 增加索引 
     *  
     * @throws Exception 
     */ 
    public static void insert() throws Exception { 
        String text5 = "hello,goodbye,man,woman"; 
        Date date1 = new Date(); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
 
        IndexWriterConfig config = new IndexWriterConfig( 
                Version.LUCENE_CURRENT, analyzer); 
        indexWriter = new IndexWriter(directory, config); 
 
        Document doc1 = new Document(); 
        doc1.add(new TextField("filename", "text5", Store.YES)); 
        doc1.add(new TextField("content", text5, Store.YES)); 
        indexWriter.addDocument(doc1); 
 
        indexWriter.commit(); 
        indexWriter.close(); 
 
        Date date2 = new Date(); 
        System.out.println("增加索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    } 
    /** 
     * 建立索引 
     *  
     * @param args 
     */ 
    public static void index() throws Exception { 
         
        String text1 = "hello,man!"; 
        String text2 = "goodbye,man!"; 
        String text3 = "hello,woman!"; 
        String text4 = "goodbye,woman!"; 
         
        Date date1 = new Date(); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
 
        IndexWriterConfig config = new IndexWriterConfig( 
                Version.LUCENE_CURRENT, analyzer); 
        indexWriter = new IndexWriter(directory, config); 
 
        Document doc1 = new Document(); 
        doc1.add(new TextField("filename", "text1", Store.YES)); 
        doc1.add(new TextField("content", text1, Store.YES)); 
        indexWriter.addDocument(doc1); 
         
        Document doc2 = new Document(); 
        doc2.add(new TextField("filename", "text2", Store.YES)); 
        doc2.add(new TextField("content", text2, Store.YES)); 
        indexWriter.addDocument(doc2); 
         
        Document doc3 = new Document(); 
        doc3.add(new TextField("filename", "text3", Store.YES)); 
        doc3.add(new TextField("content", text3, Store.YES)); 
        indexWriter.addDocument(doc3); 
         
        Document doc4 = new Document(); 
        doc4.add(new TextField("filename", "text4", Store.YES)); 
        doc4.add(new TextField("content", text4, Store.YES)); 
        indexWriter.addDocument(doc4); 
         
        indexWriter.commit(); 
        indexWriter.close(); 
 
        Date date2 = new Date(); 
        System.out.println("创建索引耗时：" + (date2.getTime() - date1.getTime()) + "ms/n"); 
    } 
 
    /** 
     * 关键字查询 
     *  
     * @param str 
     * @throws Exception 
     */ 
    public static void search(String str) throws Exception { 
        directory = FSDirectory.open(new File(INDEX_DIR)); 
        analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); 
        DirectoryReader ireader = DirectoryReader.open(directory); 
        IndexSearcher isearcher = new IndexSearcher(ireader); 
 
        QueryParser parser = new QueryParser(Version.LUCENE_CURRENT, "content",analyzer); 
        Query query = parser.parse(str); 
 
        ScoreDoc[] hits = isearcher.search(query, null, 1000).scoreDocs; 
        for (int i = 0; i < hits.length; i++) { 
            Document hitDoc = isearcher.doc(hits[i].doc); 
            System.out.println(hitDoc.get("filename")); 
            System.out.println(hitDoc.get("content")); 
        } 
        ireader.close(); 
        directory.close(); 
    } 
}

原创文章，作者：奋斗，如若转载，请注明出处：https://blog.ytso.com/tech/pnotes/19499.html

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