I have an entity that has a date modelled as an Instant
I have an DO object that has a date modelled as a Date
when i do the conversion myself in the constructor of the DO it works:
public class DO {
private Date someTimePoint;
public DO(Instant CreatedAt) {
this.someTimePoint = Date.from(CreatedAt);
}
}
and my repo works call:
List<DO> findBySomeField(UUID someField);
Give result.
However: The DO is generated and I do not have access to it, so the constructor is actually:
public DO(Date CreatedAt) {
So the question is:
Is there a way to have the conversion from Instant to Date done on the fly by Spring using the Projection methodology?
Reading https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#projections
doesn't give me any clues...
Related
I am working with Spring Data 2.0.6.RELEASE.
I am working about pagination for performance and presentation purposes.
Here about performance I am talking about that if we have a lot of records is better show them through pages
I have the following and works fine:
interface PersonaDataJpaCrudRepository extends PagingAndSortingRepository<Persona, String> {
}
The #Controller works fine with:
#GetMapping(produces=MediaType.TEXT_HTML_VALUE)
public String findAll(Pageable pageable, Model model){
Through Thymeleaf I am able to apply pagination. Therefore until here the goal has been accomplished.
Note: The Persona class is annotated with JPA (#Entity, Id, etc)
Now I am concerned about the following: even when pagination works in Spring Data about the amount the records, what about of the content of each record?.
I mean: let's assume that Persona class contains 20 fields (consider any entity you want for your app), thus for a view based in html where a report only uses 4 fields (id, firstname, lastname, date), thus we have 16 unnecessary fields for each entity in memory
I have tried the following:
interface PersonaDataJpaCrudRepository extends PagingAndSortingRepository<Persona, String> {
#Query("SELECT p.id, id.nombre, id.apellido, id.fecha FROM Persona p")
#Override
Page<Persona> findAll(Pageable pageable);
}
If I do a simple print in the #Controller it fails about the following:
java.lang.ClassCastException:
[Ljava.lang.Object; cannot be cast to com.manuel.jordan.domain.Persona
If I avoid that the view fails with:
Caused by:
org.springframework.expression.spel.SpelEvaluationException:
EL1008E:
Property or field 'id' cannot be found on object of type
'java.lang.Object[]' - maybe not public or not valid?
I have read many posts in SO such as:
java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to
I understand the answer and I am agree about the Object[] return type because I am working with specific set of fields.
Is mandatory work with the complete set of fields for each entity? Should I simply accept the cost of memory about the 16 fields in this case that never are used? It for each record retrieved?
Is there a solution to work around with a specific set of fields or Object[] with the current API of Spring Data?
Have a look at Spring data Projections. For example, interface-based projections may be used to expose certain attributes through specific getter methods.
Interface:
interface PersonaSubset {
long getId();
String getNombre();
String getApellido();
String getFecha();
}
Repository method:
Page<PersonaSubset> findAll(Pageable pageable);
If you only want to read a specific set of columns you don't need to fetch the whole entity. Create a class containing requested columns - for example:
public class PersonBasicData {
private String firstName;
private String lastName;
public PersonBasicData(String firstName, String lastName) {
this.firstName = fistName;
this.lastName = lastName;
}
// getters and setters if needed
}
Then you can specify query using #Query annotation on repository method using constructor expression like this:
#Query("SELECT NEW some.package.PersonBasicData(p.firstName, p.lastName) FROM Person AS p")
You could also use Criteria API to get it done programatically:
CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery<PersonBasicData> query = cb.createQuery(PersonBasicData.class);
Root<Person> person = query.from(Person.class);
query.multiselect(person.get("firstName"), person.get("lastName"));
List<PersonBasicData> results = entityManager.createQuery(query).getResultList();
Be aware that instance of PersonBasicData being created just for read purposes - you won't be able to make changes to it and persist those back in your database as the class is not marked as entity and thus your JPA provider will not work with it.
Problem: Native queries with Spring Data returning dates return java.sql.Date not java.time.LocalDate, despite the setup.
Context: A new project with Spring Boot 2.0.0.M5 (the latest), Hibernate 5.2.11, Hibernate-Java8 5.2.12 (which gives support for JSR310 classes as long as it's on the classpath).
Anonymized example below (the app is not really about birthdays):
public interface BirthdayRepository<T, ID extends Serializable> extends Repository<T, ID> {
#Query(value = "select day from birthdays", nativeQuery = true)
Iterable<java.sql.Date> getBirthdays(); //the return type should ideally be java.time.LocalDate
}
In the database (SQL Server), the day field is DATE and values are like 2017-10-24.
The problem is that at runtime, the Spring Data repository (whose implementation I cannot control, or is there a way?) returns java.sql.Date not java.time.LocalDate (Clarification: the return type appears to be decided by Spring Data and remains java.sql.Date even if I change the return type to be java.time.LocalDate, which is how I started to).
Isn't there a way to get LocalDate directly? I can convert it later, but (1) that's inefficient and (2) the repository methods have to return the old date/time classes, which is something I'd like to avoid. I read the Spring Data documentation, but there's nothing about this.
EDIT: for anyone having the same question, below is the solution, the converter suggested by Jens.
public class LocalDateTypeConverter {
#Converter(autoApply = true)
public static class LocalDateConverter implements AttributeConverter<LocalDate, Date> {
#Nullable
#Override
public Date convertToDatabaseColumn(LocalDate date) {
return date == null ? null : new Date(LocalDateToDateConverter.INSTANCE.convert(date).getTime());
}
#Nullable
#Override
public LocalDate convertToEntityAttribute(Date date) {
return date == null ? null : DateToLocalDateConverter.INSTANCE.convert(date);
}
}
It looks like you found a gap in the converters. Spring Data converts out of the box between java.util.Date and java.time.LocalDate but not between java.time.LocalDate and java.sql.Date and other date and time-related types in the java.sql package.
You can create your own converter to do that. You can use Jsr310JpaConverters as a template.
Also, you might want to create a feature request and if you build a converter for your use, you might even submit a pull request.
I know this is an older question, but my solution to this problem does not require a custom converter.
public interface BirthdayRepository<T, ID extends Serializable> extends Repository<T, ID> {
#Query(value = "select cast(day as date) from birthdays", nativeQuery = true)
Iterable<java.time.LocalDate> getBirthdays();
}
The CAST tells JPQL to use available java date\time types rather than java.sql.Date
I am using spring data's elastic search module, but I am having troubles building a query. It is a very easy query though.
My document looks as follows:
#Document(indexName = "triber-sensor", type = "event")
public class EventDocument implements Event {
#Id
private String id;
#Field(type = FieldType.String)
private EventMode eventMode;
#Field(type = FieldType.String)
private EventSubject eventSubject;
#Field(type = FieldType.String)
private String eventId;
#Field(type = FieldType.Date)
private Date creationDate;
}
And the spring data repository looks like:
public interface EventJpaRepository extends ElasticsearchRepository<EventDocument, String> {
List<EventDocument> findAllOrderByCreationDateDesc(Pageable pageable);
}
So I am trying to get all events ordered by creationDate with the newest event first. However when I run the code I get an exception (also in STS):
Caused by: org.springframework.data.mapping.PropertyReferenceException: No property desc found for type Date! Traversed path: EventDocument.creationDate.
So it seems that it is not picking up the 'OrderBy' part? However a query with a findBy clause (eg findByCreationDateOrderByCreationDateDesc) seems to be okay. Also a findAll without ordering works.
Does this mean that the elastic search module of spring data doesn't allow findAll with ordering?
Try adding By to method name:
findAllByOrderByCreationDateDesc
We are using Swagger 2.x and SpringFox 2.0 to document our REST service created with Spring MVC.
We have a REST response with a property List<LocalDate> dates.
In the Model Schema of the response, the label for dates is shown as 'LocalDate'. That is not intended: we would like to have 'date' or 'yyyy-MM-dd' instead.
We have this class:
public class SayHelloResponse {
private List<LocalDate> dates;
private String message;
public SayHelloResponse(String message, LocalDate... dates) {
this.message = message;
this.dates = ImmutableList.copyOf(dates);
}
public List<LocalDate> getDates() {
return dates;
}
public String getMessage() {
return message;
}
}
That results in this Model Schema:
{
"dates": [
"LocalDate"
],
"message": "string"
}
In the Model Schema, I would like to have LocalDate as 'date' or 'yyyy-MM-dd'. The way to do this seems to be with com.wordnik.swagger.annotations.ApiModelProperty but this does not have any effect (it is being picked up, as when I add #ApiModelProperty(hidden=true) it is hidden).
I created a sample rest project that shows the issue.
Any ideas how I can change LocalDate to 'date' or 'yyyy-MM-dd' in the Model Schema of Swagger?
There is a method in Docket object to replace models called directModelSubstitute(). You can use it like this to substitute LocalDate to Date object:
Docket#directModelSubstitute(LocalDate.class, Date.class)
The only problem with it that I found is that you can't change the date format.
See A/Q section in the official Springfox documentation, specifically question "How do we use Java 8 types esply. LocalDateTime?"
This is recommended in the official Springfox documentation, but doesn't effect:
Docket(DocumentationType.SWAGGER_2)..build().directModelSubstitute(LocalDate.class, java.sql.Date.class)
This effect but change format to date-time instead of date:
Docket(DocumentationType.SWAGGER_2)..build().directModelSubstitute(LocalDate.class, java.util.Date.class);
That's why I use the last one and ignore time part.
I start understanding how jersey works with JAXB. But today i faced a particular case where i want to marshall a Map of (Date,List) entries:
#XmlRootElement
#XmlAccessorType(XmlAccessType.FIELD)
public class MyClass{
#XmlJavaTypeAdapter(MapAdapter.class)
private Map<Date,List<MyObject>> = new TreeMap<Date,List<MyObject>>(new DateCompareDesc());
}
The goal here is to marshall a Map whose entry is a Date with its corresponding list of MyObject. the map is sorted in desc order.
For this i implemented an Adapter for Map (MapAdapter, following #Blaise Doughan's tutorial, http://blog.bdoughan.com/2010/07/xmladapter-jaxbs-secret-weapon.html). The problem is on the Date key. I have an Error : Unable to marshall java.util.Date. So i tried this new Date Adapter :
public class DateAdapter extends XmlAdapter<String, Date> {
#Override
public Date unmarshal(String v) throws Exception {
//not implemented
}
#Override
public String marshal(Date v) throws Exception {
return v.toString();
}
}
Where can i add #XmlJavaTypeAdapter(DateAdapter.class) so that Jersey could marhsall Date as key to my TreeMap?
Thanks.
JAXB supports the marshalling/unmarshalling of java.util.Date to the standard XML schema types: date, time, dateTime. You can control the type used with the #XmlSchemaType annotation.
http://blog.bdoughan.com/2011/01/jaxb-and-datetime-properties.html
If your date information is not represented as one of the standard XML schema types, you can use an XmlAdapter similar to the one I used the following answer to a similar question:
jaxb unmarshal timestamp
If you need to use the XmlAdapter approach, the #XmlJavaTypeAdapter annotation would be placed on the Date field of the adapted object representing the entry in the Map. Below is what this might look like based on my blog: http://blog.bdoughan.com/2010/07/xmladapter-jaxbs-secret-weapon.html.
import javax.xml.bind.annotation.XmlValue;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
public class MyMapEntryType {
#XmlAttribute
#XmlJavaTypeAdapter(DateAdapter.class)
public Date key;
public List<MyObject> value;
}