JSP + 网上书店 课程设计

package wyf; import java.sql.*; import java.util.*; public class DBBean { static Connection con; static PreparedStatement psGoodList; static PreparedStatement psGoodFromIdToPrice; static PreparedStatement psGoodFromIdToDetail; static PreparedStatement psCountRecords; static int span=5; static { try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); con=DriverManager.getConnection("jdbc:odbc:shop","",""); psGoodList= con.prepareStatement( "select sid,sname,sprice from good", ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY); psGoodFromIdToPrice=con.prepareStatement("select sprice from good where sid=?"); psGoodFromIdToDetail=con.prepareStatement("select sname,sprice from good where sid=?"); psCountRecords=con.prepareStatement( "select count(sid) from good" ); } catch(Exception e) { e.printStackTrace(); } } public static String[][] getGoodList(int cp) { String[][] result=null; Vector v=new Vector(); try { ResultSet rs=psGoodList.executeQuery(); if(cp!=1) { rs.absolute((cp-1)*span); } int count=1; while(rs.next()&&count<=span) { count++; String[] tempsa=new String[3]; tempsa[0]=rs.getString(1); tempsa[1]=rs.getString(2); tempsa[2]=rs.getString(3); v.add(tempsa); } int size=v.size(); result=new String[size][]; for(int i=0;i<size;i++) { result[i]=(String[])v.elementAt(i); } } catch(Exception e) { e.printStackTrace(); } return result; } public static double getPrice(String sid) { double dd=0; try { psGoodFromIdToPrice.setString(1,sid); ResultSet rs=psGoodFromIdToPrice.executeQuery(); rs.next(); dd=Double.parseDouble(rs.getString(1)); } catch(Exception e) { e.printStackTrace(); } return dd; } public static String[] getDetail(String sid) { String[] ss=null; try { psGoodFromIdToDetail.setString(1,sid); ResultSet rs=psGoodFromIdToDetail.executeQuery(); rs.next(); ss=new String[2]; ss[0]=rs.getString(1); ss[1]=rs.getString(2); } catch(Exception e) { e.printStackTrace(); } return ss; } public static int getTotalPage() { int tp=0; try { ResultSet rs=psCountRecords.executeQuery(); rs.next(); int count=rs.getInt(1); tp=count/span+((count%span==0)?0:1); } catch(Exception e) { e.printStackTrace(); } return tp; } public static void main(String args[]) { System.out.println(DBBean.getTotalPage()); } }