java网上购物系统

package com.bjsxt.shopping.product; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.sql.Timestamp; import java.util.ArrayList; import java.util.List; import com.bjsxt.shopping.category.Category; import com.bjsxt.shopping.util.DB; public class ProductMySQLDAO implements ProductDAO { public void add(Product p) { Connection conn = null; PreparedStatement pstmt = null; try { conn = DB.getConn(); String sql = "insert into product values (null, ?, ?, ?, ?, ?, ?)"; pstmt = DB.prepare(conn, sql); pstmt.setString(1, p.getName()); pstmt.setString(2, p.getDescr()); pstmt.setDouble(3, p.getNormalPrice()); pstmt.setDouble(4, p.getMemberPrice()); pstmt.setTimestamp(5, new Timestamp(p.getPdate().getTime())); pstmt.setInt(6, p.getCategoryId()); pstmt.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } finally { DB.close(pstmt); DB.close(conn); } } public void delete(int id) { Connection conn = null; Statement stmt = null; String sql; try { conn = DB.getConn(); sql = "delete from product where id = " + id; stmt = DB.getStatement(conn); DB.executeUpdate(stmt, sql); } finally { DB.close(stmt); DB.close(conn); } } public List<Product> getProducts() { Connection conn = DB.getConn(); Statement stmt = DB.getStatement(conn); String sql = "select * from product order by pdate desc"; ResultSet rs = DB.getResultSet(stmt, sql); List<Product> products = new ArrayList<Product>(); try { while (rs.next()) { Product p = getProductFromRs(rs); products.add(p); } } catch (SQLException e) { e.printStackTrace(); } finally { DB.close(stmt); DB.close(rs); DB.close(conn); } return products; } /** * @param lazy 为true时，只取Product的信息，否则同时取出Product内Category对象的信息 */ public int getProducts(List<Product> products, int pageNo, int pageSize, boolean lazy) { int totalRecords = -1; Connection conn = DB.getConn(); Statement stmt = DB.getStatement(conn); String sql = ""; if(lazy) { sql = "select * from product order by pdate desc"; } else { sql = "select p.id productid, p.name pname, p.descr pdescr, p.normalprice, " + " p.memberprice, p.pdate, p.categoryid , " + " c.id categoryid, c.name cname, c.descr cdescr, c.pid, c.cno, c.grade " + " from product p join category c on (p.categoryid = c.id) order by p.pdate desc"; } sql += " limit " + (pageNo - 1) * pageSize + "," + pageSize; ResultSet rs = DB.getResultSet(stmt, sql); Statement stmtCount = DB.getStatement(conn); ResultSet rsCount = DB.getResultSet(stmtCount, "select count(*) from product"); //products = new ArrayList<Product>(); 千万小心这句话不要添加 try { rsCount.next(); totalRecords = rsCount.getInt(1); while (rs.next()) { Product p = null; if(lazy) { p = this.getProductFromRs(rs); } else { p = new Product(); p.setId(rs.getInt("productid")); p.setName(rs.getString("pname")); p.setDescr(rs.getString("pdescr")); p.setNormalPrice(rs.getDouble("normalprice")); p.setMemberPrice(rs.getDouble("memberprice")); p.setPdate(rs.getTimestamp("pdate")); p.setCategoryId(rs.getInt("categoryid")); Category c = new Category(); c.setId(rs.getInt("categoryid")); c.setName(rs.getString("cname")); c.setDescr(rs.getString("cdescr")); c.setPid(rs.getInt("pid")); c.setCno(rs.getInt("cno")); c.setGrade(rs.getInt("grade")); p.setCategory(c); } products.add(p); } } catch (SQLException e) { e.printStackTrace(); } finally { DB.close(rsCount); DB.close(stmtCount); DB.close(stmt); DB.close(rs); DB.close(conn); } return totalRecords; } public Product loadById(int id) { Connection conn = null; ResultSet rs = null; Statement stmt = null; Product p = null; try { String sql = "select * from product where id = " + id; conn = DB.getConn(); stmt = DB.getStatement(conn); rs = DB.getResultSet(stmt, sql); if (rs.next()) { p = getProductFromRs(rs); } } catch (SQLException e) { e.printStackTrace(); } finally { DB.close(stmt); DB.close(rs); DB.close(conn); } return p; } public void update(Product p) { Connection conn = null; PreparedStatement pstmt = null; try { conn = DB.getConn(); String sql = "update product set name=? , descr=?, normalprice=?, memberprice=?, categoryid=? where id=?"; pstmt = DB.prepare(conn, sql); pstmt.setString(1, p.getName()); pstmt.setString(2, p.getDescr()); pstmt.setDouble(3, p.getNormalPrice()); pstmt.setDouble(4, p.getMemberPrice()); pstmt.setInt(5, p.getCategoryId()); pstmt.setInt(6, p.getId()); pstmt.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); } finally { DB.close(pstmt); DB.close(conn); } } private Product getProductFromRs(ResultSet rs) { Product p = null; try { p = new Product(); p.setId(rs.getInt("id")); p.setName(rs.getString("name")); p.setDescr(rs.getString("descr")); p.setNormalPrice(rs.getDouble("normalprice")); p.setMemberPrice(rs.getDouble("memberprice")); p.setPdate(rs.getTimestamp("pdate")); p.setCategoryId(rs.getInt("categoryid")); } catch (SQLException e) { e.printStackTrace(); } return p; } public void delete(String conditionStr) { Connection conn = null; Statement stmt = null; String sql; try { conn = DB.getConn(); sql = "delete from product " + conditionStr; stmt = DB.getStatement(conn); DB.executeUpdate(stmt, sql); } finally { DB.close(stmt); DB.close(conn); } } public int find(List<Product> products, int pageNo, int pageSize, String queryStr) { int totalRecords = -1; Connection conn = DB.getConn(); Statement stmt = DB.getStatement(conn); String sql = ""; sql = "select p.id productid, p.name pname, p.descr pdescr, p.normalprice, " + " p.memberprice, p.pdate, p.categoryid , " + " c.id categoryid, c.name cname, c.descr cdescr, c.pid, c.cno, c.grade " + " from product p join category c on (p.categoryid = c.id)" + queryStr + " order by p.pdate desc"; sql += " limit " + (pageNo - 1) * pageSize + "," + pageSize; System.out.println(sql); ResultSet rs = DB.getResultSet(stmt, sql); Statement stmtCount = DB.getStatement(conn); ResultSet rsCount = DB.getResultSet(stmtCount, "select count(*) from product " + queryStr.replaceAll("p\\.", "")); try { rsCount.next(); totalRecords = rsCount.getInt(1); while (rs.next()) { Product p = null; p = new Product(); p.setId(rs.getInt("productid")); p.setName(rs.getString("pname")); p.setDescr(rs.getString("pdescr")); p.setNormalPrice(rs.getDouble("normalprice")); p.setMemberPrice(rs.getDouble("memberprice")); p.setPdate(rs.getTimestamp("pdate")); p.setCategoryId(rs.getInt("categoryid")); Category c = new Category(); c.setId(rs.getInt("categoryid")); c.setName(rs.getString("cname")); c.setDescr(rs.getString("cdescr")); c.setPid(rs.getInt("pid")); c.setCno(rs.getInt("cno")); c.setGrade(rs.getInt("grade")); p.setCategory(c); products.add(p); } } catch (SQLException e) { e.printStackTrace(); } finally { DB.close(rsCount); DB.close(stmtCount); DB.close(stmt); DB.close(rs); DB.close(conn); } return totalRecords; } }