改造Lucene第一个例子

package cn.itcast.javaee.lucene.util;

import java.io.File;
import java.lang.reflect.Method;

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;
import cn.itcast.javaee.lucene.entity.Article;

/**
* 工具类
* @author AdminTC
*/
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("c:/itcast/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,"培训","传智是一家培训机构");
Document document = LuceneUtil.javabean2document(aritcle);

System.out.println("---------------------------------------");

Article article = (Article) LuceneUtil.document2javabean(document,Article.class);
System.out.println(article);
}

}

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 );
}
}
}