Question

我编写了类级JSR-303约束注释，它接受方法名作为参数。您设置为参数的方法名称应返回布尔值。

我有实体Foo，包含字段代码，validFrom和validTill。代码必须每次都是唯一的。例：两个实体（'AAA'，1.1.2010,31.12.2010）和（'AAA'，1.5.2011,31.5.2011）都可以两个实体（'AAA'，1.1.2010,31.12.2010）和（'AAA'，1.2.2010,31.3.2012）是错误的

现在我需要编写验证方法，检查代码是否唯一。我写道：

    public boolean isUnique() {
    if (logger.isDebugEnabled()) logger.debug("Before select");
    return entityManager.createQuery("select count(o) from Currency o where " +
            "o.code = :code and (" +
            "(o.validFrom between :validFrom and :validTill) or " +
            "(o.validTill between :validFrom and :validTill) or " +
            "(:validFrom between o.validFrom and o.validTill))",
            Long.class)
            .setParameter("code", getCode())
            .setParameter("validFrom", getValidFrom())
            .setParameter("validTill", getValidTill())
            .getSingleResult() == 0;
}

我进入了无限循环

DEBUG http-8080-2 ch.laic.bsatrak.domain.base.BaseEntity - Before select
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - processing flush-time cascades
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - dirty checking collections
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - Flushed: 1 insertions, 0 updates, 0 deletions to 1 objects
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - Flushed: 0 (re)creations, 0 updates, 0 removals to 0 collections
DEBUG http-8080-2 org.hibernate.pretty.Printer - listing entities:
DEBUG http-8080-2 org.hibernate.pretty.Printer - ch.laic.bsatrak.domain.base.Currency{id=50, createdBy=, editedBy=, createdAt=2011-04-07T14:54:52.233+02:00, validFrom=2010-01-01T00:00:00.000+01:00, code=CODE, validTill=2010-12-31T00:00:00.000+01:00, suspended=false, version=0, editedAt=null}
DEBUG http-8080-2 org.hibernate.engine.ActionQueue - changes must be flushed to space: bs_currency
DEBUG http-8080-2 ch.laic.bsatrak.domain.base.BaseEntity - Before select
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - processing flush-time cascades
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - dirty checking collections
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - Flushed: 1 insertions, 0 updates, 0 deletions to 1 objects
DEBUG http-8080-2 org.hibernate.event.def.AbstractFlushingEventListener - Flushed: 0 (re)creations, 0 updates, 0 removals to 0 collections
DEBUG http-8080-2 org.hibernate.pretty.Printer - listing entities:
DEBUG http-8080-2 org.hibernate.pretty.Printer - ch.laic.bsatrak.domain.base.Currency{id=50, createdBy=, editedBy=, createdAt=2011-04-07T14:54:52.233+02:00, validFrom=2010-01-01T00:00:00.000+01:00, code=CODE, validTill=2010-12-31T00:00:00.000+01:00, suspended=false, version=0, editedAt=null}

我怎样才能这样做？

Answer 1

必须设置FlushMode。默认值为Auto，在查询框架尝试刷新所有可能影响查询的实体之前。

.setFlushMode(FlushModeType.COMMIT)

在自定义验证器内查询

1 个答案: