productpage.java

jspservlet+mvc tomcat

package mvc;

import java.sql.*;
import java.util.*;

public class ProductPage{
    /**
     *查询数据库，获得要显示的信息，然后通过pageBean返回
     */
	public PageBean listData(int pageNum,String condition)throws Exception{	
		PageBean pageBean = new PageBean();
		pageBean.setCurPage(pageNum);
		Connection con=null;
		String c = "";
		try{
			con=DatabaseConnection.getConnection();
			Statement st = con.createStatement();
			
			if((condition!=null)&&(!condition.trim().equals(""))) {
				c = " WHERE "+ condition;
			}
			String q1 = "SELECT COUNT(*) AS total FROM userinfo "+c;
			ResultSet rs1 = st.executeQuery(q1);
			int total = 0;
			if(rs1.next()){
				total = rs1.getInt("total");
			}
			pageBean.setMaxRowCount(total);
			pageBean.setMaxPage();
			
			
			int num = pageBean.getRowsPerPage();
			int start = (pageNum-1)*num;		
			String q2="SELECT * FROM userinfo "+c+" limit "+start+","+num;
			ResultSet rs2 = st.executeQuery(q2);
			Vector v = new Vector();
			User user;	
			while(rs2.next()){							
					user = new User();
					user.setId(rs2.getInt("id"));
					user.setUsername(rs2.getString("username"));
					user.setPhone(rs2.getString("phone"));
					user.setEmail(rs2.getString("email"));
					v.add(user);
			}
			pageBean.setData(v);
			return pageBean;
		} catch(Exception e){		   
		   	e.printStackTrace();
			throw e;
		} finally{
				try{
					if(con!=null){
						con.close();
					}
				}catch(Exception e2){}
		}
	}// end of listData()

}