serialnodao.java

jsp网站开发四“酷”全书原码

package com.publish.shop.util.dao;

import java.sql.*;
import com.publish.shop.util.javabeans.*;
import com.publish.shop.util.db.DbPool;

public class SerialNoDAO {
  public static int getSerialNo(Connection con,String serialType){
        int serial = 0;
        serial = getLastSerialNo(con,serialType);
        System.out.println("serial:"+serial);
        if(serial <= 0){
            serial = 1;
            createSerialNo(con,serialType,serial);
        }
        else{
            serial ++;
            updateSerialNo(con,serialType,serial);
        }
        System.out.println("serial next:"+getLastSerialNo(con,serialType));
        return serial;
    }

    private static int getLastSerialNo(Connection con,String serialType){
            int last = -1;
            String sql = "select SerialNumber from Serial_Number";
            sql += " where serialId='"+serialType+"'";
            ResultSet rs = null;
            Statement stmt = null;
            try{
                stmt = con.createStatement();
                rs = stmt.executeQuery(sql);
                while(rs.next())
                  last = rs.getInt(1);
            }catch(Exception posEx){
            }
            finally{
              DbPool.closeResultSet(rs);
              DbPool.closeStatement(stmt);
            }
            return last;
        }
        private static int createSerialNo(Connection con,String serialType, int serialNo){
            int rs = 0;
            String sql = "insert into Serial_Number(serialId,SerialNumber) values(";
            sql += "'"+serialType+"',"+serialNo+")";
            Statement stmt = null;
            try{
                stmt = con.createStatement();
                rs = stmt.executeUpdate(sql);
                con.commit();
            }catch(Exception posEx){
              posEx.printStackTrace();
            }
            finally{
              DbPool.closeStatement(stmt);
            }
            return rs;
        }
        private static int updateSerialNo(Connection con,String serialType, int serialNo) {
            int rs = 0;
            String sql = "update Serial_Number";
            sql += " set SerialNumber="+serialNo;
            sql += " where serialId='"+serialType+"'";
            Statement stmt = null;
            try{
                con = DbPool.getConnection();
                stmt = con.createStatement();
                rs = stmt.executeUpdate(sql);
                con.commit();
            }catch(Exception posEx){
              posEx.printStackTrace();
            }
            finally{
              DbPool.closeStatement(stmt);
            }
            return rs;
        }
}