lucene第一步---6.分页

创建测试数据的索引

String path = "index";//索引目录
Analyzer analyzer = new IKAnalyzer();//采用的分词器
IndexWriter iwriter = new IndexWriter(path, analyzer, true);  
File dir = new File("data");//
File[] files = dir.listFiles();
for(int i=0;i<files.length;i++){
	Document doc = new Document();
	File file = files[i];
	System.out.println(file.getName());
	System.out.println(file.getPath());
	FileInputStream fis = new FileInputStream(file);
	String content = "";
	BufferedReader reader = new BufferedReader(new InputStreamReader(fis));

StringBuffer buffer = new StringBuffer("");
content = reader.readLine();
while (content != null) {
    buffer.append(content);
    content = reader.readLine();
}
System.out.println("content : "+buffer.toString());
doc.add(new Field("title",file.getName(),Field.Store.YES,Field.Index.ANALYZED));
doc.add(new Field("content",buffer.toString(),Field.Store.YES,Field.Index.ANALYZED));
iwriter.addDocument(doc);
}
iwriter.close();

我们创建分页类，没什么说的一个bean

import java.util.ArrayList;

import org.apache.lucene.document.Document;

public class Page{
	private static int DEFAULT_PAGE_SIZE = 5;

	private int pageSize = DEFAULT_PAGE_SIZE; // 每页的记录数

	private long start; // 当前页第一条数据在数据集合中的位置,从0开始

	private Object data; // 当前页中存放的记录,类型一般为List

	private long totalCount; // 总记录数

	public Page() {
		this(0, 0, 5,new ArrayList<Document>());
	}

	public Page(long start, long totalCount, int pageSize, Object data) {
		this.start = start;
		this.totalCount = totalCount;
		this.pageSize = pageSize;
		this.data = data;
	}
	
	/**
	 * 取得总记录数
	 * @return
	 */
	public long getTotalCount() {
		return this.totalCount;
	}
	/**
	 * 取当前页中的数据
	 * @return
	 */
	public Object getResult() {
		return this.data;
	}
	
	/**
	 * 取每页的数据容量
	 * @return
	 */
	public int getPageSize() {
		return this.pageSize;
	}
	/**
	 * 取总页数
	 * @return
	 */
	public long getTotalPageCount() {
		return totalCount % pageSize == 0 ? totalCount / pageSize : totalCount
				/ pageSize + 1;
	}
	
	/**
	 * 取当前的页号
	 * @return
	 */
	public long getCurrentPageNo(){
		return start/pageSize+1;
	}
	
	/**
	 * 该页是否有下一页.
	 */
	public boolean hasNextPage() {
		return this.getCurrentPageNo() < this.getTotalPageCount();
	}

	/**
	 * 该页是否有上一页.
	 */
	public boolean hasPreviousPage() {
		return this.getCurrentPageNo() > 1;
	}

	/**
	 * 获取任一页第一条数据在数据集的位置，每页条数使用默认值.
	 *
	 * @see #getStartOfPage(int,int)
	 */
	protected static int getStartOfPage(int pageNo) {
		return getStartOfPage(pageNo, DEFAULT_PAGE_SIZE);
	}

	/**
	 * 获取任一页第一条数据在数据集的位置.
	 *
	 * @param pageNo   从1开始的页号
	 * @param pageSize 每页记录条数
	 * @return 该页第一条数据
	 */
	public static int getStartOfPage(int pageNo, int pageSize) {
		return (pageNo - 1) * pageSize;
	}
}

下面我们做一个分页方法并进行测试

public class PageSearcher {

	@SuppressWarnings("unchecked")
	public static void main(String[] args) throws IOException {
		String path = "index";//索引目录
		Directory dir = FSDirectory.open(new File(path));
		IndexSearcher searcher = new IndexSearcher(dir,true);
		Term term = new Term("content","网友");
		Query query = new TermQuery(term);
		Page page = getPageQuery(3, 3, query, searcher);
		System.out.println("当前页号 "+page.getCurrentPageNo());
		System.out.println("存在上一页? " + page.hasPreviousPage());
		System.out.println("存在下一页? " + page.hasNextPage());
		System.out.println("每页的记录数 " + page.getPageSize());
		System.out.println("总页数 " + page.getTotalPageCount());
		System.out.println("总记录数 " + page.getTotalCount());
		//显示页面内容
		
		ArrayList<Document> docs = (ArrayList<Document>) page.getResult();
		for(Document doc:docs){
			System.out.println(doc.get("content"));
		}
		
		
	}
	/**
	 * 获取当前页
	 * @param pageNo 页号 从1开始
	 * @param pageSize 每页显示的最多记录条数
	 * @param query Query
	 * @param searcher Searcher
	 * @return
	 */
	public static Page getPageQuery(int pageNo,int pageSize,Query query,Searcher searcher){
		TopScoreDocCollector topCollector=null;
		List<Document> result = new ArrayList<Document>();
		try {
			//得到查询结果的总记录数
			topCollector = TopScoreDocCollector.create(searcher.maxDoc(), false);
			searcher.search(query, topCollector);
			//查询当页的记录
			ScoreDoc [] docs = topCollector.topDocs((pageNo-1)*pageSize,pageSize).scoreDocs;
			for(ScoreDoc scdoc : docs){
				try {
					result.add(searcher.doc(scdoc.doc));
				} catch (CorruptIndexException e) {
					e.printStackTrace();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return new Page(Page.getStartOfPage(pageNo,pageSize),topCollector.getTotalHits(),pageSize,result);
		} catch (IOException e1) {
			e1.printStackTrace();
		}
		
		return new Page();
	}
}