Java 使用JPA 2.1标准API之间的LocalDate
在我的实体中,我有两个字段:Java 使用JPA 2.1标准API之间的LocalDate,java,jpa,jpa-2.1,jpa-criteria,Java,Jpa,Jpa 2.1,Jpa Criteria,在我的实体中,我有两个字段: private LocalDate startDate = LocalDate.of(1900, 1, 1); private LocalDate endDate = LocalDate.of(3000, 1, 1); 使用JPA标准API,我想选择LocalDate.now()>startDate和LocalDate.now()
private LocalDate startDate = LocalDate.of(1900, 1, 1);
private LocalDate endDate = LocalDate.of(3000, 1, 1);
使用JPA标准API,我想选择LocalDate.now()>startDate
和LocalDate.now()
的实体
我尝试了以下方法:
predicates.add(builder.greaterThan(LocalDate.now(), path.<LocalDate> get(Entity_.startDate)));
predicates.add(builder.lessThan(builder.currentDate(), path.<LocalDate> get(Entity_.endDate)));
predicates.add(builder.greaterThan(LocalDate.now(),path.get(Entity.startDate));
add(builder.lessThan(builder.currentDate(),path.get(Entity.endDate));
但我得到了这个错误:
The method greaterThan(Expression<? extends Y>, Expression<? extends Y>) in the type CriteriaBuilder is not applicable for the arguments (LocalDate, Path<LocalDate>)
方法大于(表达式由于jpa2.1
尚不直接支持LocalDate
,因此您似乎需要一个AttributeConverter
。假设您有一个实体
@Entity
@Getter
public class LocalDateEntity {
@Id
@GeneratedValue
private Long id;
@Setter
private LocalDate startDate = LocalDate.of(1900, 1, 1);
@Setter
private LocalDate endDate = LocalDate.of(3000, 1, 1);
}
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<LocalDateEntity> cq = cb.createQuery(LocalDateEntity.class);
Root<LocalDateEntity> from = cq.from(LocalDateEntity.class);
Expression<Date> expCurrDate = cb.currentDate();
cq.where(
cb.and(
cb.greaterThan(from.get("endDate"), expCurrDate)
,cb.lessThan(from.get("startDate"), expCurrDate)
// OR for example
// cb.lessThan(expCurrDate, from.get("endDate"))
// ,cb.greaterThan(expCurrDate, from.get("startDate"))
// both are expressions no matter in what order
// but note the change in Predicate lt vs. gt
)
);
TypedQuery<LocalDateEntity> tq = em.createQuery(cq);
您可以像这样使用AttributeConverter
// import java.sql.Date not java.util.Date;
@Converter(autoApply = true) // this makes it to apply anywhere there is a need
public class LocalDateConverter implements AttributeConverter<LocalDate, Date> {
@Override
public Date convertToDatabaseColumn(LocalDate date) {
return Date.valueOf(date);
}
@Override
public LocalDate convertToEntityAttribute(Date value) {
return value.toLocalDate();
}
}
注意:while Predicatebetween(..)
也可以,但有点不同。它包括开始和结束日期。不是100%确定,但您可能应该使用大于(表达式)的方法
// import java.sql.Date not java.util.Date;
@Converter(autoApply = true) // this makes it to apply anywhere there is a need
public class LocalDateConverter implements AttributeConverter<LocalDate, Date> {
@Override
public Date convertToDatabaseColumn(LocalDate date) {
return Date.valueOf(date);
}
@Override
public LocalDate convertToEntityAttribute(Date value) {
return value.toLocalDate();
}
}
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<LocalDateEntity> cq = cb.createQuery(LocalDateEntity.class);
Root<LocalDateEntity> from = cq.from(LocalDateEntity.class);
Expression<Date> expCurrDate = cb.currentDate();
cq.where(
cb.and(
cb.greaterThan(from.get("endDate"), expCurrDate)
,cb.lessThan(from.get("startDate"), expCurrDate)
// OR for example
// cb.lessThan(expCurrDate, from.get("endDate"))
// ,cb.greaterThan(expCurrDate, from.get("startDate"))
// both are expressions no matter in what order
// but note the change in Predicate lt vs. gt
)
);
TypedQuery<LocalDateEntity> tq = em.createQuery(cq);