How can I make a HQL using Instant from java.time - spring

Question

I am developing a small project using spring-jpa. I decided to use java.time to deal with date problems. Everything was working fine until I had to deal with HQL.
So I am trying to make this query:
#Query("SELECT sensor "
+ "FROM TrashSensor sensor "
+ "join sensor.measurementList measurement "
+ "WHERE sensor.id = 100 AND measurement.instantOfMeasure > '2017-01-01'")
public TrashSensor findTrashSensorByIdCustom();
But the type of measurement.instantOfMeasure is a Instant from java.time.
So this last AND of my WHERE clause is always returning true so I don't get the filter I need.
How can I make this comparison using HQL and java.time? Does Hibernate support this??

Answer 1

You can develop it with
1 way -> (in TrashSensorRepository interface )
#Query("SELECT sensor "
+ "FROM TrashSensor sensor "
+ "join sensor.measurementList measurement "
+ "WHERE sensor.id =:sensorId AND measurement.instantOfMeasure > :instantOfMeasure")
public TrashSensor findTrashSensorByIdCustom(#Param("sensorId") sensorId, #Param("instantOfMeasure") Instant instantOfMeasure);
The types from the java.time package are directly mapped to corresponding SQL types(Since Java 8)
LocalDate is mapped to DATE
LocalTime and OffsetTime are mapped to TIME
Instant, LocalDateTime, OffsetDateTime and ZonedDateTime are mapped to TIMESTAMP
2 way -> (if you have created custom utility class for run HQL dynamically)
// Utility for run custom dynamic HQL query
#Service
#Transactional
public class HibernateQueryService {
private final Logger log = LoggerFactory.getLogger(HibernateQueryService.class);
private JpaContext jpaContext;
public List executeHibernateQuery(String sql, Class entity){
log.debug("HibernateQuery executing: "+sql);
Session session = jpaContext.getEntityManagerByManagedType(Article.class).unwrap(Session.class);
return session.createQuery(sql, entity).getResultList();
}
}
// Custom converter
public class CustomConverter{
public static Timestamp toTimestamp(Instant time){
return time != null ? Timestamp.from(time) : null;
}
public static Instant toInstant(Timestamp timestamp){
return timestamp != null ? timestamp.toInstant() : null;
}
}
// Solution
public class Solution2{
public static makeIt(){
boolean isFirst = true;
String query = "SELECT sensor "
+ "FROM TrashSensor sensor "
+ "join sensor.measurementList measurement ";
if(sensor.id != null){
query += isFirst ? "WHERE " : "AND ";
query += "sensor.id="+sensor.id+" ";
isFirst = false;
}
if(measurement.instantOfMeasure != null){
query += isFirst ? "WHERE " : "AND ";
query += "measurement.instantOfMeasure > "+toTimestamp(measurement.instantOfMeasure)+" ";
}
List<TrashSensor> hibernateQueryService.executeHibernateQuery(query, TrashSensor.class);
}
}