Spring Data Redis Repository support does not read back embedded complex objects - spring-boot

I have a spring-boot application (1.4RC1, I know it's RC, but Spring Data Redis 1.7.2 is not) where I'm using spring-boot-starter-redis.
The application uses a Spring Data Repository (CrudRepository) which should save an object (using #RedisHash annotation) with String and Boolean properties and one custom class property, which also has only Strings and Longs as properties.
When I save an object (via the repository), everything went fine and I can see all the properties in the database as I would expect.
When I want to read the data from the database (via the repository) I only get the properties from the parent object. The custom class property is null.
I would expect to get the property loaded from the database as well. As the documentation states you can write a custom converter, but since I don't need to do that, when I want to write the data, I shouldn't need to write a reading converter as well.
I wonder if I need to annotate the custom class property, but I couldn't find anything in the documentation. Can you point me in the right direction?
The classes are as follows:
Class sample:
#Data
#EqualsAndHashCode(exclude = {"isActive", "sampleCreated", "sampleConfiguration"})
#RedisHash
public class Sample {
#Id
private String sampleIdentifier;
private Boolean isActive;
private Date sampleCreated;
private SampleConfiguration sampleConfiguration;
public Sample(String sampleIdentifier, SampleConfiguration sampleConfiguration){
this.sampleIdentifier = sampleIdentifier;
this.sampleConfiguration = sampleConfiguration;
}
}
Class SampleConfiguration:
#Data
public class SampleConfiguration {
private String surveyURL;
private Long blockingTime;
private String invitationTitle;
private String invitationText;
private String participateButtonText;
private String doNotParticipateButtonText;
private String optOutButtonText;
private Long frequencyCappingThreshold;
private Long optOutBlockingTime;
}

I added #NoArgsConstructor to my Sample class as Christoph Strobl suggested. Then the repository reads the SampleConfiguration correctly. Thanks, Christoph!

Related

How to access Spring properties from an entity?

I have a spring app, that pushes data in an s3 bucket.
public class Ebook implements Serializable {
#Column(name= "cover_path", unique = true, nullable = true)
private String coverPath;
private String coverDownloadUrl;
#Value("${aws.cloudfront.region}")
private String awsCloudFrontDns;
#PostLoad
public void init(){
// I want to access the property here
System.out.println("PostConstruct");
String coverDownloadUrl = "https://"+awsCloudFrontDns+"/"+coverPath;
}
When a data is pushed, let's say my cover here, I get the key 1/test-folder/mycover.jpg which is the important part of the future http URL of the data.
When I read the data from database, I enter inside #PostLoad method and I want construct the complete URL using the cloudfront value. This value changes frequently so we don't want to save hardly in the database.
How could I do to construct my full path just after reading the data in database?
The only way to do this is to use a service that update the data after using repository to read it? For readbyId it can be a good solution, but for reading list or using other jpa methods, this solutions won't work because I have each time to create a dedicated service for the update.
It doesn't look good for Entity to depend on property.
How about EntityListener.
#Component
public class EbookEntityListener {
#Value("${aws.cloudfront.region}")
private String awsCloudFrontDns;
#PostLoad
void postload(Ebook entity) { entity.updateDns(awsCloudFrontDns); }
}
I recommend trying this way :)

Class based projections using a DTO in Spring Data Jpa is not working

In my Spring Boot application, I am trying to implement a class based projection using DTOs as described at:
https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#projections.dtos
I have a domain class that looks like:
#Entity
#Table(name="metadatavalue")
public class MetadataValue {
#Id
#Column(name="metadata_value_id")
private Integer metadataValueId;
#Column(name="resource_id", insertable=false, updatable=false)
private Integer resourceId;
#Column(name="metadata_field_id", insertable=false, updatable=false)
private Integer metadataFieldId;
#Column(name="text_value")
private String textValue;
more class members, getters and setters, etc follow.
I also have a simple DTO class with one member:
public class MetadataDTO {
private String textValue;
public MetadataDTO(String textValue) {
this.textValue = textValue;
}
public String getTextValue() {
return textValue;
}
}
My repository class is:
public interface MetadataValueRepository extends CrudRepository<MetadataValue, Integer> {
#Query("SELECT m from MetadataValue m WHERE m.handle.handle = :handle AND m.resourceTypeId=m.handle.resourceTypeId")
List<MetadataValue> findAllByHandle(#Param("handle") String handle);
#Query("SELECT new path.to.my.package.domain.MetadataDTO(m.textValue AS textValue) FROM MetadataValue m "
+ "WHERE m.handle.handle = :handle AND m.resourceTypeId=m.handle.resourceTypeId")
List<MetadataDTO> findAllByHandleDTO(#Param("handle") String handle);
}
The first method, findAllByHandle works as expected, but when running the second method, findAllByHandleDTO, which I had hoped to return the projection, my application throws the error:
java.lang.IllegalArgumentException: Couldn't find PersistentEntity for type class path.to.my.package.domain.MetadataDTO!
I have also tried extending from JpaRepository with the same result. In another attempt, I tried using an Interface based projection which resulted in an almost identical stacktrace, with an internal class substituted for my class.
My project is spring-boot 2.3.0 with Spring Web, Spring Data JPA, Rest Repositories, and PostgreSQL Driver.
Can anybody help me understand what I am doing wrong and set me in the right direction?
Thanks so much!
Update on this question: (I have added the tag spring-data-rest). Experimenting, I have learned that I can successfully call my method, for instance, in the run() method of my application class. It's only when I call the method as a rest endpoint that I see the error. Is this simply an issue of incompatibility with Spring Data Rest?

How do I get Spring's Data Rest Repository to retrieve data by its name instead of its id

I am using Spring Data's Rest Repositories from spring-boot-starter-data-rest, with Couchbase being used as the underlining DBMS.
My Pojo for the object is setup as so.
#Document
public class Item{
#Id #GeneratedValue(strategy = UNIQUE)
private String id;
#NotNull
private String name;
//other items and getters and setters here
}
And say the Item has an id of "xxx-xxx-xxx-xxx" and name of "testItem".
Problem is, that when I want to access the item, I need to be accessible by /items/testItem, but instead it is accessible by /items/xxx-xxx-xxx-xxx.
How do I get use its name instead of its generated id, to get the data.
I found out the answer to my own question.
I just need to override the config for the EntityLookup.
#Component
public class SpringDataRestCustomization extends RepositoryRestConfigurerAdapter {
#Override
public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config) {
config.withEntityLookup().forRepository(UserRepository.class).
withIdMapping(User::getUsername).
withLookup(UserRepository::findByUsername);
}
}
Found the info here, though the method name changed slightly.
https://github.com/spring-projects/spring-data-examples/tree/master/rest/uri-customization
If you want query the item by name and want it perform as querying by id,you should make sure the name is unique too.You cant identify a explicit object by name if all objects have a same name,right?
With jpa you could do it like:
#NotNull
#Column(name="name",nullable=false,unique=true)
private String name;

Service cannot auto-wire in Entity class

I needed a RoleMappingService class(which is annotated by #Service) object into a Employee class (which is annotated by #Entity)
below are my classes
********************* RoleMappingsService class **********************
#Service
public class RoleMappingsService {
#Autowired
RolesMappingDao rolesMappingDao;
public List<RolesMappings> getRolesMappingByauthSystemRole(String authSystemRole) {
return rolesMappingDao.getRolesMappingByauthSystemRole(authSystemRole);
}
}
############### Employee class
#Configurable
#Component
#Entity
#NamedQuery(name = "Employee.findAll", query = "SELECT e FROM Employee e")
public class Employee implements Serializable, UserDetails {
#Autowired
#Transient
RoleMappingsService roleMappingsService;
public static final String STATUS_ACTIVE = "ACTIVE";
public static final String STATUS_INACTIVE = "INACTIVE";
public static final String STATUS_LOCKED = "LOCKED";
public static final String STATUS_ONLEAVE = "ONLEAVE";
public static final String STATUS_EXPIRED = "EXPIRED";
private static final long serialVersionUID = 1L;
#Id
#Column(name = "emp_id")
private String empId;
#Column(name = "emp_password")
private String empPassword;
#Column(name = "emp_email")
private String empEmail;
#Column(name = "emp_address")
private String empAddress;
#Column(name = "emp_age")
private int empAge;
#Column(name = "emp_firstname")
private String empFirstname;
}
Here Autowire is not working for roleMappingsService and the object is always found null. However I tried to autowire same object in some other service and there Autowire is perfectly working.
( I know Entity class is only used for representing database table but in my case I need to set some field values which depend on another table so need to fetch data using service)
JB Nizet is totally right
I'll try to provide more explanations here.
Spring can Autowire only beans, objects that it manages, and not arbitrary objects.
Entities are usually created from within a JPA (Hibernate) and are not something that you want to manage by Spring.
There is a related discussion available here but bottom line you should never do something like this.
Why not?
Here are a couple of questions/reasons:
Maybe these entities will go outside spring context at all (serialization), what should that reference contain? Should we also serialize the service? How?
What will happen if the method that turns to the service will be called "outside" the spring driven application (maybe even in different JVM)?
If there are, say 1000 objects returned by that query, do you really want all of them to reside in application context? Or maybe should they be of "prototype" scope?
As you see, it doesn't play nice with spring concepts. I think the reason for it is that Hibernate and JPA do not "support" an idea of methods inside entities, it's just a different framework. I know there are other frameworks that do allow such a concept, but Hibernate/JPA just doesn't, period
So instead of trying to inject the service into the entity bean, probably you should redesign the application so that the service method will be called from outside, maybe via some facade, and entities will be just populated by query, and then "enriched" with additional information if we're talking about SELECT queries, or, alternatively, some information should be pre-set on entity objects, generated by the Business Logic Layer and only then the entity object should be stored in DB

Spring MongoDB Save

I'm creating a Spring Boot application and I am using AngularJS on the frontend.
Upon submitting a form with the appropiate parameters, Spring is supposed to use bookRepository.save() method in order to save the provided data in the MongoDB. The problem is, this action gets carried on, but the structure of my model is not respected.
#Document(collection = "books")
public class Book {
private String id;
private String title;
private String author;
private String description;
private String cover;
// Getters and setters below.
}
The final outcome after following the above process: instead of having a record following the above structure inserted in MongoDB, I only end up with a field containing _id and _class.
Any ideas as to why is this happening?

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