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  • LuceneUtil使用反射,封装通用的方法

    package loaderman.util;
    
    import java.io.File;
    import java.lang.reflect.Method;
    
    import loaderman.entity.Article;
    import org.apache.commons.beanutils.BeanUtils;
    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.document.Field.Index;
    import org.apache.lucene.document.Field.Store;
    import org.apache.lucene.index.IndexWriter.MaxFieldLength;
    import org.apache.lucene.store.Directory;
    import org.apache.lucene.store.FSDirectory;
    import org.apache.lucene.util.Version;
    
    /**
     * 工具类*/
    public class LuceneUtil {
    
        private static Directory directory;
        private static Version version;
        private static Analyzer analyzer;
        private static MaxFieldLength maxFieldLength;
    
        static{
            try {
                directory =  FSDirectory.open(new File("D:/IndexDBDBDB"));
                version = Version.LUCENE_30;
                analyzer = new StandardAnalyzer(version);
                maxFieldLength = MaxFieldLength.LIMITED;
            } catch (Exception e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            }
        }
    
        public static Directory getDirectory() {
            return directory;
        }
    
        public static Version getVersion() {
            return version;
        }
    
        public static Analyzer getAnalyzer() {
            return analyzer;
        }
    
        public static MaxFieldLength getMaxFieldLength() {
            return maxFieldLength;
        }
    
        //不让外界new该帮助类
        private LuceneUtil(){}
    
        //将JavaBean转成Document对象
        public static Document javabean2document(Object obj) throws Exception{
            //创建Docuemnt对象
            Document document = new Document();
            //获取obj引用的对象字节码
            Class clazz = obj.getClass();
            //通过对象字节码获取私有的属性
            java.lang.reflect.Field[] reflectFields = clazz.getDeclaredFields();
            //迭代
            for(java.lang.reflect.Field reflectField : reflectFields){
                //强力反射
                reflectField.setAccessible(true);
                //获取属性名,id/title/content
                String name = reflectField.getName();
                //人工拼接方法名
                String methodName = "get" + name.substring(0,1).toUpperCase()+name.substring(1);
                //获取方法,例如:getId()/getTitle()/getContent()
                Method method = clazz.getMethod(methodName,null);
                //执行方法
                String value = method.invoke(obj,null).toString();
                //加入到Document对象中去,这时javabean的属性与document对象的属性相同
                document.add(new Field(name,value,Store.YES,Index.ANALYZED));
            }
            //返回document对象
            return document;
        }
    
        //将Document对象转成JavaBean对象
        public static Object document2javabean(Document document,Class clazz) throws Exception{
            Object obj = clazz.newInstance();
            java.lang.reflect.Field[] reflectFields = clazz.getDeclaredFields();
            for(java.lang.reflect.Field reflectField : reflectFields){
                reflectField.setAccessible(true);
                String name = reflectField.getName();//id/title/content
                String value = document.get(name);//1/培训/传智是一家培训机构
                BeanUtils.setProperty(obj,name,value);//封装javabean对应的属性中去,通过setXxx()方法
            }
            return obj;
        }
        //测试
        public static void main(String[] args) throws Exception{
            Article aritcle = new Article(1,"学习","学习使人快乐...");
            Document document = LuceneUtil.javabean2document(aritcle);
    
            System.out.println("---------------------------------------");
    
            Article article = (Article) LuceneUtil.document2javabean(document,Article.class);
            System.out.println(article);
        }
    
    }

    package loaderman.secondapp;
    
    import java.util.ArrayList;
    import java.util.List;
    
    import loaderman.entity.Article;
    import loaderman.util.LuceneUtil;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.index.IndexWriter;
    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.junit.Test;
    
    
    /**
     * 重构
    
     */
    public class SecondApp {
    
        /**
         * 创建索引库
         */
        @Test
        public void createIndexDB() throws Exception{
            Article article = new Article(1,"培训","传智是一家it培训机构");
            //Article article = new Article(2,"培训","北大是一家it培训机构");
            //Article article = new Article(3,"培训","中大是一家it培训机构");
            Document document = LuceneUtil.javabean2document(article);
            IndexWriter indexWriter = new IndexWriter(LuceneUtil.getDirectory(),LuceneUtil.getAnalyzer(),LuceneUtil.getMaxFieldLength());
            indexWriter.addDocument(document);
            indexWriter.close();
        }
    
        /**
         * 根据关键字从索引库中查询符合条件的数据
         */
        @Test
        public void findIndexDB() throws Exception{
            String keywords = "培训";
            List<Article> articleList = new ArrayList<Article>();
            QueryParser queryParser = new QueryParser(LuceneUtil.getVersion(),"content",LuceneUtil.getAnalyzer());
            Query query = queryParser.parse(keywords);
            IndexSearcher indexSearcher = new IndexSearcher(LuceneUtil.getDirectory());
            TopDocs topDocs = indexSearcher.search(query,100);
            for(int i=0;i<topDocs.scoreDocs.length;i++){
                ScoreDoc scoreDoc = topDocs.scoreDocs[i];
                int no = scoreDoc.doc;
                Document document = indexSearcher.doc(no);
                Article article = (Article)LuceneUtil.document2javabean(document,Article.class);
                articleList.add(article);
            }
            for(Article a : articleList){
                System.out.println( a );
            }
        }
    }
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  • 原文地址:https://www.cnblogs.com/loaderman/p/10059142.html
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