Jsp+Servlet+JavaBean购物车示例

package com.kp.conn; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.Iterator; import java.util.Set; import com.kp.entity.Goods; public class GetGoods { ArrayList<Goods> al = new ArrayList<Goods>(); //获取所有商品的方法 public ArrayList<Goods> getAllGoods(){ Connection conn = Conn.getConn(); String sql = "select * from Goods"; try { Statement stat = conn.createStatement(); ResultSet rs = stat.executeQuery(sql); while(rs.next()){ Goods goods = new Goods(); goods.setGoodsId(rs.getInt("goodsId")); goods.setGoodsName(rs.getString("goodsName")); goods.setGoodsPhoto(rs.getString("goodsPhoto")); goods.setGoodsPrice(rs.getString("goodsPrice")); goods.setGoodsDesc(rs.getString("goodsDesc")); al.add(goods); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return al; } //获取部分商品的信息,用于检索购物车内的商品的信息 public ArrayList<Goods> getAllGoods(Set goodsId){ Connection conn = Conn.getConn(); String sql = "select * from Goods" + " where goodsId in(" ; //用迭代器循环商品编号 Iterator it = goodsId.iterator(); while(it.hasNext()){ sql += it.next().toString() + ","; } //去掉最后一个逗号 sql = sql.substring(0, sql.length()-1); sql += ")"; System.out.println(sql); try { Statement stat = conn.createStatement(); ResultSet rs = stat.executeQuery(sql); while(rs.next()){ Goods goods = new Goods(); goods.setGoodsId(rs.getInt("goodsId")); goods.setGoodsName(rs.getString("goodsName")); goods.setGoodsPhoto(rs.getString("goodsPhoto")); goods.setGoodsPrice(rs.getString("goodsPrice")); goods.setGoodsNum(1); goods.setGoodsDesc(rs.getString("goodsDesc")); al.add(goods); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return al; } //查询单个商品的方法 public Goods getGoods(int goodsId){ Goods goods = null; Connection conn = Conn.getConn(); String sql = "select * from Goods" + " where goodsId =" + goodsId ; try { Statement stat = conn.createStatement(); ResultSet rs = stat.executeQuery(sql); if(rs.next()){ goods = new Goods(); goods.setGoodsId(rs.getInt("goodsId")); goods.setGoodsName(rs.getString("goodsName")); goods.setGoodsPhoto(rs.getString("goodsPhoto")); goods.setGoodsPrice(rs.getString("goodsPrice")); goods.setGoodsDesc(rs.getString("goodsDesc")); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return goods; } //查询当前页的商品记录 //pageSize 每页显示的记录数 //pageNow 当前页的页码 public ArrayList<Goods> getPageGoods(int pageSize,int pageNow){ ArrayList<Goods> al = null; Connection conn = Conn.getConn(); String sql = "select Top " + pageSize + " * from Goods where goodsId not in(" + " select Top " + pageSize*(pageNow -1) + " goodsId from Goods)"; System.out.println(sql); try { Statement stat = conn.createStatement(); ResultSet rs = stat.executeQuery(sql); al = new ArrayList<Goods>(); while(rs.next()){ Goods goods = new Goods(); goods.setGoodsId(rs.getInt("goodsId")); goods.setGoodsName(rs.getString("goodsName")); goods.setGoodsPhoto(rs.getString("goodsPhoto")); goods.setGoodsPrice(rs.getString("goodsPrice")); goods.setGoodsDesc(rs.getString("goodsDesc")); al.add(goods); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return al; } //获取总页数的方法 //页数的计算 //如果 总记录数%pageSize == 0 //pageNum = 总记录数/pageSize //否则pageNum = (int)(总记录数/pageSize)+1 public int getPageCount(int pageSize){ int pageNum = 0;//总页数 int pageCount = 0;//总记录数 Connection conn = Conn.getConn(); String sql = "select count(*) as count from Goods" ; try { Statement stat = conn.createStatement(); ResultSet rs = stat.executeQuery(sql); if(rs.next()){ pageCount = rs.getInt("count"); } //计算页数的方法 if(pageCount%pageSize == 0) pageNum = pageCount/pageSize; else pageNum = (int)(pageCount/pageSize)+1; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return pageNum; } }