?

public ? class ?DBHelper? {????
???? public ? static ?Connection?getConnection()? {????
????????Connection?conn? = ? null ;????
???????? try ? {????
????????????Class.forName( " com.mysql.jdbc.Driver " );????
????????????conn? = ?DriverManager.getConnection( " jdbc:mysql://localhost/ad?useUnicode=true&characterEncoding=GBK&jdbcCompliantTruncation=false " ,????
???????????????????? " root " ,? " root " );????
????????} ? catch ?(Exception?e)? {????
????????????e.printStackTrace();????
????????} ????
???????? return ?conn;????
????} ????
} ????
???
???????? /* dao中的方法 */ ???
???? public ?List < Adv > ?getAllAdvs()? {????
????????????
????????Connection?conn? = ? null ;????
????????ResultSet?rs? = ? null ;????
????????PreparedStatement?stmt? = ? null ;????
????????String?sql? = ? " select?*?from?adv?where?id?=?? " ;????
????????List < Adv > ?advs? = ? new ?ArrayList < Adv > ();????
???
????????conn? = ?DBHelper.getConnection();????
???????? if ?(conn? != ? null )? {????
???????????? try ? {????
????????????????stmt? = ?conn.prepareStatement(sql);????
????????????????????????????????stmt.setInt( 1 ,? new ?Integer( 1 ));????
????????????????rs? = ?stmt.executeQuery();????
???
???????????????? if ?(rs? != ? null )? {????
???????????????????? while ?(rs.next())? {????
????????????????????????Adv?adv? = ? new ?Adv();????
????????????????????????adv.setId(rs.getLong( 1 ));????
????????????????????????adv.setName(rs.getString( 2 ));????
????????????????????????adv.setDesc(rs.getString( 3 ));????
????????????????????????adv.setPicUrl(rs.getString( 4 ));????
???
????????????????????????advs.add(adv);????
????????????????????} ????
????????????????} ????
????????????} ? catch ?(SQLException?e)? {????
????????????????e.printStackTrace();????
????????????} ? finally ? {????
???????????????? try ? {????
????????????????????stmt.close();????
????????????????????conn.close();????
????????????????} ? catch ?(SQLException?e)? {????
????????????????????e.printStackTrace();????
????????????????} ????
????????????} ????
????????} ????
???????? return ?advs;????
????} ?