public static void main(String[] args) { try { Connection conn = DBHelper.getConnection(); if (conn == null) { System.out.println("数据库连接失败。"); } else { System.out.println("数据库连接成功!"); } } catch (SQLException ex) { ex.printStackTrace(); } }
public Items getItemsById(int id) { Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; try { conn = DBHelper.getConnection(); String sql = "select * from items where id =?;"; stmt = conn.prepareStatement(sql); stmt.setInt(1, id); rs = stmt.executeQuery(); while (rs.next()) { Items item = new Items(); item.setId(rs.getInt("id")); item.setName(rs.getString("name")); item.setCity(rs.getString("city")); item.setNumber(rs.getInt("number")); item.setPrice(rs.getInt("price")); item.setPicture(rs.getString("picture")); return item; } } catch (SQLException ex) { ex.printStackTrace(); } finally { try { stmt.close(); } catch (SQLException e) { e.printStackTrace(); } try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } rs = null; stmt = null; } return null; }
// 获得所有的商品信息 public ArrayList<Items> getAllItems() { Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; ArrayList<Items> list = new ArrayList<Items>(); try { conn = DBHelper.getConnection(); String sql = "select * from items"; stmt = conn.prepareStatement(sql); rs = stmt.executeQuery(); while (rs.next()) { Items item = new Items(); item.setId(rs.getInt("id")); item.setName(rs.getString("name")); item.setCity(rs.getString("city")); item.setNumber(rs.getInt("number")); item.setPrice(rs.getInt("price")); item.setPicture(rs.getString("picture")); list.add(item); } } catch (SQLException ex) { ex.printStackTrace(); } finally { try { stmt.close(); } catch (SQLException e) { e.printStackTrace(); } try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } rs = null; stmt = null; } return list; }