通过上两篇的学习,想必已经入了门了,今天来看索引域选项中的几个值得设置
先来看一个构造器:
/** * Create a field by specifying its name, value and how it will * be saved in the index. Term vectors will not be stored in the index. * * @param name The name of the field * @param value The string to process * @param store Whether <code>value</code> should be stored in the index * @param index Whether the field should be indexed, and if so, if it should * be tokenized before indexing * @throws NullPointerException if name or value is <code>null</code> * @throws IllegalArgumentException if the field is neither stored nor indexed */ public Field(String name, String value, Store store, Index index) { this(name, value, store, index, TermVector.NO); }
我们向Document添加Field可以有更多的设置,那么都是什么意思呢?
name:字段名,很容易理解
value:字段值,也很容易理解
store和index怎么解释,下面就来看一下这两个选项的可选值:
Field.Store.YES或者NO(存储域选项)
设置为YES表示或把这个域中的内容完全存储到文件中,方便进行文本的还原
设置为NO表示把这个域的内容不存储到文件中,但是可以被索引,此时内容无法完全还原
Field.Index(索引选项)
Index.ANALYZED:进行分词和索引,适用于标题、内容等
Index.NOT_ANALYZED:进行索引,但是不进行分词,如果身份证号,姓名,ID等,适用于精确搜索
Index.ANALYZED_NOT_NORMS:进行分词但是不存储norms信息,这个norms中包括了创建索引的时间和权值等信息
Index.NOT_ANALYZED_NOT_NORMS:即不进行分词也不存储norms信息
Index.NO:不进行索引
写个例子看看,由于pom文件与之前的一样,就不贴出了,直接看例子代码:
3.5版本:
package com.darren.lucene35; import java.io.File; 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.index.IndexReader; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.index.IndexWriterConfig; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.TopDocs; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.util.Version; public class IndexUtil { private static final String[] ids = { "1", "2", "3" }; private static final String[] authors = { "Darren", "Tony", "Grylls" }; private static final String[] titles = { "Hello World", "Hello Lucene", "Hello Java" }; private static final String[] contents = { "Hello World, I am on my way", "Today is my first day to study Lucene", "I like Java" }; /** * 建立索引 */ public static void index() { IndexWriter indexWriter = null; try { // 1、创建Directory Directory directory = FSDirectory.open(new File("F:/test/lucene/index")); // 2、创建IndexWriter Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_35); IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_35, analyzer); indexWriter = new IndexWriter(directory, config); int size = ids.length; for (int i = 0; i < size; i++) { // 3、创建Document对象 Document document = new Document(); // 看看四个参数的意思 /** * Create a field by specifying its name, value and how it will be saved in the index. Term vectors will * not be stored in the index. * * @param name * The name of the field * @param value * The string to process * @param store * Whether <code>value</code> should be stored in the index * @param index * Whether the field should be indexed, and if so, if it should be tokenized before indexing * * public Field(String name, String value, Store store, Index index) { this(name, value, * store, index, TermVector.NO); } */ // 4、为Document添加Field // 对ID存储,但是不分词也不存储norms信息,这个norms中包括了创建索引的时间和权值等信息 document.add(new Field("id", ids[i], Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS)); // 对Author存储,但是不分词也不存储norms信息,这个norms中包括了创建索引的时间和权值等信息 document.add(new Field("author", authors[i], Field.Store.YES, Field.Index.NOT_ANALYZED)); // 对Title存储,分词 document.add(new Field("title", titles[i], Field.Store.YES, Field.Index.ANALYZED)); // 对Content不存储,但是分词 /** * 注:添加内容或文件是默认是不存储的,这个查询时可以证明这个问题 * * new Field(name, reader) * * 那么问题来了,如果想存文件内容怎么办呢? * * 那就把文件读出来,比如读出字符串,然后不就能按字符串的方式存储啦 */ document.add(new Field("content", contents[i], Field.Store.NO, Field.Index.ANALYZED)); // 5、通过IndexWriter添加文档到索引中 indexWriter.addDocument(document); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (indexWriter != null) { indexWriter.close(); } } catch (Exception e) { e.printStackTrace(); } } } /** * 搜索 */ public static void search() { IndexReader indexReader = null; try { // 1、创建Directory Directory directory = FSDirectory.open(new File("F:/test/lucene/index")); // 2、创建IndexReader indexReader = IndexReader.open(directory); // 3、根据IndexReader创建IndexSearch IndexSearcher indexSearcher = new IndexSearcher(indexReader); // 4、创建搜索的Query // 使用默认的标准分词器 Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_35); // 在content中搜索Lucene // 创建parser来确定要搜索文件的内容,第二个参数为搜索的域 QueryParser queryParser = new QueryParser(Version.LUCENE_35, "content", analyzer); // 创建Query表示搜索域为content包含Lucene的文档 Query query = queryParser.parse("Lucene"); // 5、根据searcher搜索并且返回TopDocs TopDocs topDocs = indexSearcher.search(query, 10); // 6、根据TopDocs获取ScoreDoc对象 ScoreDoc[] scoreDocs = topDocs.scoreDocs; for (ScoreDoc scoreDoc : scoreDocs) { // 7、根据searcher和ScoreDoc对象获取具体的Document对象 Document document = indexSearcher.doc(scoreDoc.doc); // 8、根据Document对象获取需要的值 System.out.println("id : " + document.get("id")); System.out.println("author : " + document.get("author")); System.out.println("title : " + document.get("title")); /** * 看看content能不能打印出来,为什么? */ System.out.println("content : " + document.get("content")); } } catch (Exception e) { e.printStackTrace(); } finally { try { if (indexReader != null) { indexReader.clone(); } } catch (Exception e) { e.printStackTrace(); } } } }
我在注释中留了问题,现在我们是这样添加content字段的:
document.add(new Field("content", contents[i], Field.Store.NO, Field.Index.ANALYZED));
测试代码如下:
package com.darren.lucene35; import org.junit.Test; public class IndexUtilTest { @Test public void testIndex() { IndexUtil.index(); } @Test public void testSearch() { IndexUtil.search(); } }
现在跑一下测试看看效果,结果如下:
id : 2 author : Tony title : Hello Lucene content : null
为什么content为null,就是因为没有存,那么我们存一下看看
document.add(new Field("content", contents[i], Field.Store.YES, Field.Index.ANALYZED));
再跑一下测试,注意,要先跑索引,再跑查询
id : 2 author : Tony title : Hello Lucene content : Today is my first day to study Lucene
现在content有值了
索引选项与此类同,不在赘述
4.5版本:
5.0版本:
稍后更新4.5版本和5.0版本
时间: 2024-10-09 15:17:49