public Object loginByNameAndPass(String name, String password) {
User user=nuzdao.fetch(User.class, Cnd.where("name", "=", name).and("password", "=", password));
}

@Table("t_user")
public class User {
@Id
private int id;

 private String name;

 private String password;

 private String salt;

 private Date createTime;

 private Date updateTime;

}
控制台报出nuzdao.fetch方法的空指针异常，求解啊