Lucene全文检索的【增、删、改、查】 实例
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(); } }
