搜索结果排序

  1 package cn.itcast.g_sort;
  2 
  3 import java.util.ArrayList;
  4 import java.util.List;
  5 
  6 import org.apache.lucene.document.Document;
  7 import org.apache.lucene.document.Field;
  8 import org.apache.lucene.document.Field.Index;
  9 import org.apache.lucene.document.Field.Store;
 10 import org.apache.lucene.index.IndexWriter;
 11 import org.apache.lucene.index.IndexWriter.MaxFieldLength;
 12 import org.apache.lucene.queryParser.MultiFieldQueryParser;
 13 import org.apache.lucene.queryParser.QueryParser;
 14 import org.apache.lucene.search.IndexSearcher;
 15 import org.apache.lucene.search.Query;
 16 import org.apache.lucene.search.Sort;
 17 import org.apache.lucene.search.SortField;
 18 import org.apache.lucene.search.TopDocs;
 19 import org.apache.lucene.search.highlight.Formatter;
 20 import org.apache.lucene.search.highlight.Highlighter;
 21 import org.apache.lucene.search.highlight.QueryScorer;
 22 import org.apache.lucene.search.highlight.Scorer;
 23 import org.apache.lucene.search.highlight.SimpleFragmenter;
 24 import org.apache.lucene.search.highlight.SimpleHTMLFormatter;
 25 import org.apache.lucene.util.Version;
 26 import org.junit.Test;
 27 
 28 import cn.itcast._domain.Article;
 29 import cn.itcast._util.ArticleDocumentUtils;
 30 import cn.itcast._util.LuceneUtils;
 31 
 32 public class TestApp {
 33 
 34     // 建立索引
 35     @Test
 36     public void testCreateIndex() throws Exception {
 37         // 准备数据
 38         Article article = new Article();
 39         article.setId(30);
 40         article.setTitle("准备Lucene的开发环境");
 41         article.setContent("如果信息检索系统在用户发出了检索请求后再去互联网上找答案，根本无法在有限的时间内返回结果。");
 42 
 43         // 放到索引库中
 44         // 1, 把Article转为Document
 45         Document doc = ArticleDocumentUtils.articleToDocument(article);
 46 
 47         doc.setBoost(0.5F); // 1F表示正常得分，大于1表示高分，小于1表示低分
 48 
 49         // 2, 把Document放到索引库中
 50         LuceneUtils.getIndexWriter().addDocument(doc);
 51         LuceneUtils.getIndexWriter().commit();
 52     }
 53 
 54     // 搜索
 55     @Test
 56     public void testSearch() throws Exception {
 57         // 准备查询条件
 58         String queryString = "lucene";
 59 
 60         // 执行搜索
 61         List<Article> list = new ArrayList<Article>();
 62 
 63         // 1，把查询字符串转为Query对象（从title和content中查询）
 64         QueryParser queryParser = new MultiFieldQueryParser(Version.LUCENE_30, new String[] { "title", "content" }, LuceneUtils.getAnalyzer());
 65         Query query = queryParser.parse(queryString);
 66 
 67         // 2，执行查询，得到中间结果
 68         IndexSearcher indexSearcher = new IndexSearcher(LuceneUtils.getDirectory()); // 指定所用的索引库
 69         // TopDocs topDocs = indexSearcher.search(query, 100); // 最多返回前n条结果
 70 
 71         // ========================================================================================== 【创建高亮器】
 72         // indexSearcher.search(query, n);
 73         // indexSearcher.search(query, filter, n);
 74         // indexSearcher.search(query, filter, n, sort);
 75 
 76         // Sort sort = new Sort( new SortField("id", SortField.INT) ); // 按id升序排列
 77         Sort sort = new Sort(new SortField("id", SortField.INT, true)); // 按id降序排列（true表示降序，false表示升序）
 78 
 79         TopDocs topDocs = indexSearcher.search(query, null, 100, sort);
 80 
 81         // ==========================================================================================
 82 
 83         // 3，处理结果
 84         for (int i = 0; i < topDocs.scoreDocs.length; i++) {
 85             float score = topDocs.scoreDocs[i].score;
 86             System.out.println("---> score : " + score);
 87 
 88             // 根据编号拿到Document数据
 89             int docId = topDocs.scoreDocs[i].doc; // Document的内部编号
 90             Document doc = indexSearcher.doc(docId);
 91             // 把Document转为Article
 92             Article article = ArticleDocumentUtils.documentToArticle(doc);
 93             list.add(article);
 94         }
 95         indexSearcher.close();
 96 
 97         // 显示结果
 98         System.out.println("总结果数：" + list.size());
 99         for (Article a : list) {
100             System.out.println("------------------------------");
101             System.out.println("id = " + a.getId());
102             System.out.println("title = " + a.getTitle());
103             System.out.println("content = " + a.getContent());
104         }
105     }
106 }