三层架构用户注册案例-DAO层

public class UserDao {
JdbcTemplate jdbcTemplate = new JdbcTemplate(DruidUtils.getDataSource());

//保存用户到数据库
public int saveUser(User user){
    try{
        return jdbcTemplate.update("insert into user (uname,upasswd) values (?,?);",
                user.getUname(),user.getUpasswd());
    }catch (Exception e){
        e.printStackTrace();
        //throw new RuntimeException(e);
        return 0;
    }
}

//从数据库查询是否有相同的记录
public User findUser(String uname){
    try{
        //因为queryForObject如果没有找到数据不是返回null,而是抛出异常
        //所以捕获异常，返回null
        String sql = "select * from user where uname = ?";
        return jdbcTemplate.queryForObject(sql,new BeanPropertyRowMapper(User.class),uname);
    }catch (Exception e){

        return null;
    }

}

}