JAVA MYSQL做分页

看main

package com.hcwy.test.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.hcwy.basic.jdbc.DBConnection;
import com.hcwy.basic.page.PageBean;

public class ArticlesDAO {

	private static final Map HashMap = null;

	private PreparedStatement pstmt;
	
	private ResultSet rs;

	private Connection con;
	
//	private DBConnection conn;
	
	
	public Connection conn(){
		try {
			Class.forName("com.mysql.jdbc.Driver");
			try {
				con=DriverManager.getConnection("jdbc:mysql://localhost:3316/hcwy","root","root");
			} catch (SQLException e) {
				e.printStackTrace();
			}
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		return con;
	}
	
	
	//查询SQL
	public ArrayList chaSQL(String sql){
		ArrayList list=new ArrayList();
		try {
			
			pstmt=this.conn().prepareStatement(sql);
			rs=pstmt.executeQuery();
			ResultSetMetaData rsmd=rs.getMetaData();
			int count=rsmd.getColumnCount();
			while(rs.next()){
//				System.out.println("名字是-->"+rsmd.getColumnName(i)+"\t 得到的object是-->"+rs.getObject(i)+"   "+i);
				HashMap map=new HashMap();
				for(int i=0;i<count;i++){
					map.put(rsmd.getColumnName(i+1), rs.getObject(i+1));
				}
				list.add(map);
				
			}
			
			
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;

}
	
	//查询所总条数
	public int count(String name){
		String sql="select count(*) as aa from "+name;
		int i=0;
		try {
			pstmt=this.conn().prepareStatement(sql);
			rs=pstmt.executeQuery();
			if(rs.next()){
				i=rs.getInt("aa");
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return i;
	}
	
	
	
	//查询SQL带分页
	public ArrayList chaSQL(String sql,String name,PageBean page){
		ArrayList list=new ArrayList();
		if(page!=null){
			page.setTotalCount(this.count(name));
			sql=sql+" limit "+page.getStart()+","+page.getPageSize();
			
		}
		System.out.println(sql);
		try {
			
			pstmt=this.conn().prepareStatement(sql);
			rs=pstmt.executeQuery();
			ResultSetMetaData rsmd=rs.getMetaData();
			
			int count=rsmd.getColumnCount();//得到表里字段的总数
			while(rs.next()){
//				System.out.println("名字是-->"+rsmd.getColumnName(i)+"\t 得到的object是-->"+rs.getObject(i)+"   "+i);
				HashMap map=new HashMap();
				for(int i=0;i<count;i++){
					map.put(rsmd.getColumnName(i+1), rs.getObject(i+1));//名字和值
				}
				list.add(map);
				
			}
			
			
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;

}
	
	
	
	
	
	public static void main(String[] args) {
	
		 PageBean page=new PageBean();
		ArticlesDAO dd=new ArticlesDAO();
		ArrayList list=dd.chaSQL("select * from articles","articles",page);//如果这里不写page和articles的意思 就是说不要分页
		//任何对象都能解析
		for(int i=0;i<list.size();i++){
			HashMap map=(HashMap)list.get(i);
			
			Iterator it=map.keySet().iterator();
			while(it.hasNext()){
				Object id=it.next();
				System.out.println(""+map.get(id));
				
			}
				
				System.out.println("\n");
			
		}
		
		
//		ArticlesDAO dd=new ArticlesDAO();
//		System.out.println(dd.count("articles"));
		
		
		
	}
	
	
}

在看PAGEBEAN

package com.hcwy.basic.page;

public class PageBean {

	private static final int DEFAULT_PAGE_SIZE = 20;

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

	private int start=0;  // 当前页第一条数据在List中的位置,从0开始

	private int page=1;  //当前页

	private int totalPage=0;  //总计有多少页

	private int totalCount=0;  // 总记录数
////////////////
//	构造函数
	public PageBean() {
	}

	public PageBean(int page) {
		this.page=page;
	}

/////////////////

	public void setPage(int page) {
		if(page>0) {
			start=(page-1)*pageSize;
			this.page = page;
		}
	}
	
	public int getPage() {
		return page;
	}

	public int getPageSize() {
		return pageSize;
	}

	public PageBean setPageSize(int pageSize) {
		this.pageSize = pageSize;
		return this;
	}
	/**
	 * @return the start
	 */
	public int getStart() {
		return start;
	}

	//	此位置根据计算得到
	protected void setStart() {
	}
	
/**
	 * @return the totalCount
	 */
	public int getTotalCount() {
		return totalCount;
	}
	
	public void setTotalCount(int totalCount) {
		this.totalCount=totalCount;
		totalPage = (int) Math.ceil((totalCount + pageSize - 1) / pageSize);
		start=(page-1)*pageSize;
	}
	
	//	总页面数根据总数计算得到
	protected void setTotalPage() {
		
	}
	
	public int getTotalPage() {
		return totalPage;
	}
	
	
///////////////
	//获取上一页页数
	public int getLastPage() {
		if(hasLastPage()) {
			return page-1;
		}
		return page;
	}
	public int getNextPage() {
		if(hasNextPage()) {
			return page+1;
		}
		return page;
	}
	/**
	 * 该页是否有下一页.
	 */
	public boolean hasNextPage() {
		return page < totalPage;
	}

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

	
}

评论

1 楼 wenjinglian 2010-04-02  

那去用用