pageview.java

jsp制作的一个信息管理系统源码,完整实用版

package common;

import java.sql.*;

/**
 * Title: PageView
 * Description: 分页
 * Copyright: Copyright (c) 2002
 * Company: nettech
 * @author pwbell
 * @version 1.0
 */

public final class PageView {
	
	private ResultSet myResults;
	
	private int 			currentPageNo; 	// 当前页码
	private int 			pageSize; 			// 每页记录数
	private int 			recordCount; 		// 总记录数
	private int 			pageCount; 			// 总页码数

	
	public PageView(ResultSet rs) {
	
		myResults     = rs;
    currentPageNo = 1;
    pageSize      = 15;
    
    // compute record count
    if(myResults != null) {
    	try {
    		myResults.last();
    		recordCount = myResults.getRow();
    	} catch(SQLException ex) {
				System.err.println("PageView.getRecordCount():" + ex.getMessage());
			}
		} else {
			recordCount = 0;
		}
	}


	/**
	 * 取得给定页码的纪录集
	 */	
	public ResultSet getPage(int pageNo){

  	if(recordCount < 1)
    	return null;
  	this.setPageCount();
		
		try {			
    	if(pageNo > pageCount)
				currentPageNo = pageCount; //输入页码数大于总页码数的处理
			else if(pageNo < 1)
				currentPageNo = 1;
			else
				currentPageNo = pageNo;

			if (pageCount > 0) {
      	//将记录指针定位到待显示页的第一条记录上
      	myResults.absolute((currentPageNo - 1) * pageSize + 1);
			}
		} catch (SQLException ex) {
			System.out.print("PageView.getPage():" + ex.getMessage());
		}
    return myResults;
	}

	public int getRecordCount() {

		return this.recordCount;
	}

	/**
	 * 设定每页显示记录数目(默认为每页显示15条记录)
	 */
	public void setPageSize(int size) {
		
		this.pageSize = size;  	
		if(this.pageSize < 1)
			this.pageSize = 15;
	}
	
	public int getPageSize() {
	
		return this.pageSize;
	}
	
	public int getPageCount() {
	
		return this.pageCount;
	}
	
	private void setPageCount() {
	
		if((recordCount % pageSize) == 0) {
			this.pageCount = recordCount / pageSize;
		} else {
			this.pageCount = recordCount / pageSize + 1;
		}		
	}	
	
}