Lucene-使用

import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
import org.apache.lucene.queryParser.MultiFieldQueryParser;
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.util.Version;
import org.junit.Test;

import com.itheima11.lucene.bean.Article;
import com.itheima11.lucene.utils.DocumentUtils;
import com.itheima11.lucene.utils.LuceneUtils;

public class ArticleIndex {
    /**
     * 创建一个索引
     */
    @Test
    public void testCreateIndex() throws Exception{
        //创建一个article对象
        Article article = new Article();
        article.setAid(1L);
        article.setTitle("lucene是一个全文检索引擎");
        article.setContent("baidu,google都是很好的全文检索引擎");
        //创建一个indexWriter
        IndexWriter indexWriter = 
                    new IndexWriter(LuceneUtils.directory, LuceneUtils.analyzer, MaxFieldLength.LIMITED);
        //把article转化成document
        Document document = DocumentUtils.article2Document(article);
        //把document加入到索引库中
        indexWriter.addDocument(document);
        indexWriter.close();
    }

    @Test
    public void testSearchIndex() throws Exception{
         IndexSearcher indexSearcher = new IndexSearcher(LuceneUtils.directory);
         QueryParser queryParser = 
                    new MultiFieldQueryParser(
                            Version.LUCENE_30,
                            new String[]{"title","content"},
                            LuceneUtils.analyzer);
         Query query = queryParser.parse("lucene");
         TopDocs topDocs = indexSearcher.search(query, 1);
         ScoreDoc[] scoreDocs = topDocs.scoreDocs;
         List
 articles = new ArrayList
();
         for (ScoreDoc scoreDoc : scoreDocs) {
            int index = scoreDoc.doc;
            Document document = indexSearcher.doc(index);
            Article article = DocumentUtils.document2Article(document);
            articles.add(article);
         }

         for (Article article : articles) {
            System.out.println(article.getAid());
            System.out.println(article.getTitle());
            System.out.println(article.getContent());
        }
    }

    /**
     * 删除
     *   不是把原来的cfs文件删除掉了，而是多了一个del文件
     */
    @Test
    public void testDelete() throws Exception{
        /**
         * 关键词对象
         *   要查找一些字段：字段的名称为"title",字段中含有"lucene"的关键词
         */
        Term term = new Term("title","lucene");
        IndexWriter indexWriter = 
                new IndexWriter(
                        LuceneUtils.directory,
                        LuceneUtils.analyzer,
                        MaxFieldLength.LIMITED);
        indexWriter.deleteDocuments(term);
        indexWriter.close();
    }

    /**
     * 修改
     *    先删除后增加
     */
    @Test
    public void testUpdate() throws Exception{
        Term term = new Term("title","lucene");
        IndexWriter indexWriter = 
                new IndexWriter(
                        LuceneUtils.directory,
                        LuceneUtils.analyzer,
                        MaxFieldLength.LIMITED);

        Article article = new Article();
        article.setAid(1L);
        article.setTitle("lucene是一个全文检索引擎");
        article.setContent("-----------");
        Document doc = DocumentUtils.article2Document(article);
        /**
         * term参数是用来删除的
         * doc是用来增加的
         */
        indexWriter.updateDocument(term, doc);
        indexWriter.close();
    }
}