小编cra*_*udy的帖子

我正在实现fragment screen包含root view pager哪个包含child fragment,第child fragment一个view pager包含显示图像.

它在第一次显示相当不错,但当fragment包含的内容root view pager被删除并再次替换(使用新关键字fragment screen)时,roow view pager不会显示child fragment.

这是我的来源部分.

    @AfterViews // this is the method of fragment screen
    protected void afterViews() {
        api(HotelDetailAPI.class).getProduct("hotels", getArguments().getInt("itemId"), new Callback<Hotel>(this) {
            @Override
            public void success(Hotel _hotel, Response response) {
                hotel = _hotel;
                HotelDetailPagerAdapter adapter = new HotelDetailPagerAdapter(getFragmentManager());
                contentViewPager.setAdapter(adapter);
                contentViewPager.setBackgroundColor(0xffffff);
                super.success(hotel, response);
            }

            @Override
            public void failure(RetrofitError error) { …

我知道byte不是一个足以包含read方法结果的正确类型.
因此,read方法返回int类型值.
但我认为短类型比int更有效.
它可以包含范围-256~255的值.
为什么read方法返回int,而不是short？

org.springframework.dao.InvalidDataAccessApiUsageException: org.hibernate.loader.MultipleBagFetchException: 不能同时取多个包: [Order.items, OrderItem.options];

以上是我加入如下三个表时遇到的一个例外。

订单项选项.java

@Entity
public class OrderItemOption {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  @Column(name = "item_option_id")
  private Long id;

  @Column(name = "item_id", nullable = false)
  private Long itemId;

  @ManyToOne(fetch = FetchType.LAZY)
  @JoinColumn(
      name = "item_id",
      referencedColumnName = "item_id",
      insertable = false,
      updatable = false
  )
  private OrderItem orderItem;
}

订单项.java

@Entity
public class OrderItem {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  @Column(name = "item_id")
  private Long id;

  @Column(name = "order_id", nullable = false)
  private Long orderId;

  @ManyToOne(fetch = FetchType.LAZY) …