在JDBC简单封装的基础上实现
public class UserDao{
public static void testGetUser(String userName) throws Exception{
Connection conn=null;
PreparedStatement preparedStatement=null;//Statement换为PreparedStatement
ResultSet resultSet=null;
try{
conn=JdbcUtils.getConnetcion();
//查询语句参数化，防止SQL注入
String sql="select * from user where userName=?";
preparedStatement=conn.prepareStatement(sql);
preparedStatement.setString(1,userName);
resultSet=preparedStatement.excuteQuery();
while(resultSet.next()){
System.out.println(resultSet.getObject(1)+" "+resultSet.getObject(2));
}
}finally{
JdbcUtils.freeResource(resultSet,preparedStatement,conn);
}
}
}