Question

在这里，我试图将两个结果作为一个回复返回，并且不确定哪个选项可能对它有好处。在这里它以列表形式返回，

List<FixedDeposit> fdList = em.createQuery(sb.toString())
            .setParameter("start", dateFrom)
            .setParameter("end", dateTo)
            .setFirstResult(start).setMaxResults(limit)
            .getResultList();

所以我得到了

List<FDSearchResult> searchList = getSearchResult(fdList); 
response.setData(searchList);
return response;

现在我又要回复另一个回复了。这是计算，

Double sum = 0.0;
sum = (Double) em.createQuery("SELECT SUM(deposit_amount)FROM fd_fixed_deposit where fd.status in ('ACT','REN','WDR') and fd.maturityDate between :start and :end ")
                .setParameter("start", dateFrom)
                .setParameter("end", dateTo).getSingleResult();

那么如何通过响应来返回结果呢？请帮忙

我将发布完整的方法，

public Response<List<FDSearchResult>> loadMaturedFDByRange(String fromDate, String toDate, final Integer start,
        final Integer limit) {
    final Response<List<FDSearchResult>> response = new Response<List<FDSearchResult>>();
    Date dateFrom = DateUtils.parseDate("dd/MM/yyyy", fromDate, null);
    Date dateTo = DateUtils.parseDate("dd/MM/yyyy", toDate, null);
    Long count = 0L;
    Double sum = 0.0;
    try {
        count = (Long) em.createQuery("SELECT COUNT(fd) FROM FixedDeposit fd where fd.status in ('ACT','REN','WDR') "
                + "and fd.maturityDate between :start and :end ")
                .setParameter("start", dateFrom)
                .setParameter("end", dateTo).getSingleResult();
    } catch (NoResultException nre) {
        count = 0L;
    }
    StringBuilder sb = new StringBuilder();
    sb.append("SELECT fd FROM FixedDeposit fd where fd.status in ('ACT','REN','WDR') and fd.maturityDate between :start and :end ");
    List<FixedDeposit> fdList = em.createQuery(sb.toString())
            .setParameter("start", dateFrom)
            .setParameter("end", dateTo)
            .setFirstResult(start).setMaxResults(limit)
            .getResultList();

    sum = (Double) em.createQuery("SELECT SUM(deposit_amount)FROM fd_fixed_deposit where fd.status in ('ACT','REN','WDR') and fd.maturityDate between :start and :end ")
                .setParameter("start", dateFrom)
                .setParameter("end", dateTo).getSingleResult();

    List<FDSearchResult> searchList = getSearchResult(fdList);
    response.setData(searchList);
    response.setPagination(new Response().new PaginationInfo(count));
    return response;
}

Answer 1

在这个例子中，我将创建一个Object Container来保存这两个对象并返回该对象。

public class MyContainer
{
   List<FixedDeposit> fdList;
   List<FDSearchResult> searchList;

   public MyContainer()
   {

   }
}

我就是这样做的。

Answer 2

您可以通过结果对象返回所有相关数据。只需创建一个可以获得所有需要值的新类。

Answer 3

两个选项：

HashMap中。类型转换对象分别为响应和Double。这不是一个好习惯

您可以创建一个可以封装不同对象类型的自定义类。泛型是你需要的。

public class MultiReturn<T> {
  public final String name;
  public final T object;

  public NamedObject(String name, T object) {
     this.name = name;
     this.object = object;
  }
}

如何从一个Java方法返回多个对象？

3 个答案: