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JPA/Hibernate Spring boot-primary key one entity referred as an instance to other entity not working

I have generated master tables using liquibase. I have created the corresponding models in spring boot now I want to maintain a relation ship between those models.
I have one table called Vehicle_Type, it is already pre-populated using liquibase.
#Data
#Entity
#Table(name="VEHCILE_TYPE")
public class VehicleType {
#Id
private int id;
#Column(name="DISPLAY_NAME")
private String displayName;
#Column(name="TYPE")
private String type;
#Column(name="CREATED_DATE")
private LocalDateTime createdDate;
#Column(name="UPDATED_DATE")
private LocalDateTime updateDate;
}
now what I want to achieve is, I have one child entity, I have refer the VehicleType instance inside that entity as depicted below
#Data
#Entity
#EqualsAndHashCode(callSuper = true)
#Table(name = "NON_MSIL_VEHICLE_LAYOUT")
public class NonMsilVehicleLayout extends BaseImagesAndLayout {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "NMV_SEQ")
#SequenceGenerator(sequenceName = "NON_MSIL_VEH_SEQUENCE", allocationSize = 1, name = "NMV_SEQ")
private int id;
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name = "VEH_TYPE", referencedColumnName = "id")
private VehicleType vehicleType;
public interface VehType {
String getVehType();
}
}
The problem is when I tries to save entity NonMsilVehicleLayout, then it tries to first insert the data in VEHICLE_TYPE table also. which should not going to be happen.
I don't want that, I want JPA will pick the correct ID from VEHICLE_TYPE table and place it inside the corresponding table for NonMsilVehicleLayout, because the id of VEHICLE_TYPE table is act as foreign key in Non_Msil_Vehicle_Layout table.
log.info("Inside saveLayout::Start preparing entity to persist");
String resourceUri = null;
NonMsilVehicleLayout vehicleLayout = new NonMsilVehicleLayout();
VehicleType vehicleType=new VehicleType();
vehicleType.setType(modelCode);
vehicleLayout.setVehicleType(modelCode);
vehicleLayout.setFileName(FilenameUtils.removeExtension(FilenameUtils.getName(object.key())));
vehicleLayout.setS3BucketKey(object.key());
I know I missed something, but unable to figure it out.

You are creating a new VehicleType instance setting only the type field and set the vehicleType field of NonMsilVehicleLayout to that new instance. Since you specified CascadeType.ALL on NonMsilVehicleLayout#vehicleType, this means to Hibernate, that it has to persist the given VehicleType, because the instance has no primary key set.
I guess what you rather want is this code:
vehicleLayout.setVehicleType(
entitManager.createQuery("from VehicleType vt where vt.type = :type", VehicleType.class)
.setParameter("type", typeCode)
.getSingleResult()
);
This will load the VehicleType object by type and set that object on NonMsilVehicleLayout#vehicleType, which will then cause the foreign key column to be properly set to the primary key value.

Finally, after some workaround, I got the mistake, the column name attribute was incorrect, so I made it correct and remove the referencedColumn and Cascading.
Incorrect:
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name = "VEH_TYPE", referencedColumnName = "id")
private VehicleType vehicleType;
Correct:
#OneToOne
#JoinColumn(name = "VEHICLE_TYPE")
private VehicleType vehicleTypes;
also I have added the annotation #Column in the referende entity VehicleImage
public class VehicleType {
#Id
#Column(name = "ID") // added this one
private int id;
}
That bit workaround solved my problem, now I have achieved what I exactly looking for.

JPA merge unable to update values in table

I am trying to use JPA to make a simple update to my table column in MYSQL.
Here is the snippet:
public Node get_folder(long fileID) {
try {
List resList = nodeFacade.list_parent(fileID, LinkType.FILE);
List resList1 = nodeFacade.list_parent(fileID, LinkType.VER_LINKS);
if (resList == null) {
throw new Exception("failed to get folder of a file." +
nodeFacade.getMsg());
}
if (resList.size() > 1) {
throw new Exception("one file cannot be attached to more than one folder(s).");
}
//fixed bugs: modified here to display different version
if(resList1.size()==1){
Fmedia fmedia = em.find(fileID,Fmedia.class);
fmedia.setFstatus(2);
em.merge(fmedia);
return (Node) resList1.get(0);
}
Now, fmedia is the table and I want to update an existing record of a value in fstatus column of the table. The error I got was:
Caused by: com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Column 'FEXT' cannot be null
FEXT is a column in the same table and it's a not nullable column but there's already a value tied to that record.The exception is thrown at the line em.merge(fmedia). I am confused what is the issue here.
I couldn't use save since my JPA is the older version.
Does anyone know what am I doing wrong?
EDIT: Entity code:
#Entity
#Table(name = "fmedia")
public class Fmedia implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Basic(optional = false)
#NotNull
#Column(name = "NODEID")
private Long nodeid;
#Basic(optional = false)
#Column(name = "FONAME")
private String foname;
#Basic(optional = false)
#Column(name = "FGNAME")
private String fgname;
#Basic(optional = false)
#Column(name = "FEXT")
private String fext;
#Basic(optional = false)
#Column(name = "FFULPATH")
private String ffulpath;
#Column(name = "FTYPE")
private int ftype;
#Basic(optional = false)
#Column(name = "FSIZE")
private long fsize;
#Column(name = "FREMARK")
private String fremark;
#Column(name = "FSTATUS")
private int fstatus;
#Column(name = "FDESC")
private String fdesc;
#Column(name = "MODIFYDATE")
#Temporal(TemporalType.DATE)
private Date ModifyDate;
#Size(max = 3000)
#Column(name = "FNTFREMARK")
private String fntfremark;
#Transient
private Fverinfo fver;

Merge is used for detach entities.
If you want to update an existing entity, use fetch + update.
1) fetch exiting Entity by nodeid
2) update necessary fields on that Entity (e.g. fmedia.setFstatus(2))
3) save the entity (if you're using Hibernate, the save is not necessary, Hibernate will still issue an Update statement)
Fmedia fmedia = repository.findOne(nodeid); //manged entity-update
fmedia.setFstatus(2); // hibernate will issue an update, cause the entity is managed
repository.save(fmedia) //redundant save anti-pattern, don't call save
Using entityManager:
entityManager.find(Fmedia.class, nodeId);
If you want to fetch your entity based on something else, rather than the primaryId, you will have to crate a query:
entityManager.createQuery("select m from Fmedia m where m.foname = :foname");

Merge does not do that you need to fetch the existing entity and update that entity instead of persisting a new one with same id, so like:
Fmedia fmedia = em.find(FMEdia.class, fileId);
fmedia.setFstatus(2);
em.persist(fmedia);
Merge is for attaching existing but detached entity to persistence context and your new FMedia(..) is not detached but just new.

Spring JPA: Select specific columns on join with annotation/JPQL

I am trying to get familiar with spring and jpa. For start there is a table anime_details containing details of an anime. As it can have many genres, db has another table named genre. The intermediate table to contain their many to many relationship entries is also there. When I query for any anime by id, it should return the details of the anime along with the genres.
It does return an object with details of the anime and list of Genre objects (which is as expected). But what I want is to restrict the columns that will be fetched from Genre objects. For example only id or just id and name (In case there are more columns other than these).
AnimeDetails
#Getter
#Setter
#Entity
#Table(name = "anime_details")
public class AnimeDetails {
#Id
#SequenceGenerator(name = "animeDetailsSeq", sequenceName =
"anime_details_id_seq",
allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator =
"animeDetailsSeq")
private Integer id;
private String name;
private Integer episodes;
private Date started;
private Date ended;
private String status;
#ManyToMany
#JoinTable(
name = "anime_genre",
joinColumns = #JoinColumn(name = "details_id", referencedColumnName = "id"),
inverseJoinColumns = #JoinColumn(name = "genre_id", referencedColumnName = "id"))
#JsonManagedReference
private List<Genre> genres;
protected AnimeDetails() {
}
}
Genre
#Data
#Entity
#Table(name = "genre")
public class Genre {
#Id
#SequenceGenerator(name = "genreSeq", sequenceName = "genre_id_seq",
allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "genreSeq")
private Integer id;
private String name;
#ManyToMany(mappedBy = "genres")
List<AnimeDetails> animes;
protected Genre() {
}
}
Expected payload
{
"id": 2,
"name": "Your Name",
"episodes": 1,
"started": "2016-08-25T18:00:00.000+0000",
"ended": "2016-08-25T18:00:00.000+0000",
"status": "Completed",
"genres": [
{
"id": 5,
"name": "Drama"
},
{
"id": 10,
"name": "Supernatural"
}
]
}
Right now, I get the result and manually get columns one by one and set those in a DTO. But that is not efficient as the database query is already fetching more data than needed.
Is there any specific annotation/property/jpql to reduce it?

Indeed was looking for a proper solution regarding the same issue , cause as you pointed out it is creating performance issues as there are huge useless data loads between the APP and the DB. Imagine that there could be, not only one query but much more and you need a global optimization solution...
From the first place Spring DATA is not supporting this operation so its leading you at the manual configuration and set up on a DTO reference. The same applies if you were using a custom Object and returning that inside the JPQL with the constructor trick , or else write a native query , get back a List<Object> and again manually map the data back to your actual object , which is the most efficient but not elegant solution
More info in this link , but try to check both answers for the details.
The other thing is that as you are using hibernate underneath , which is providing custom mappers , you could always write up your custom HQL(not jpql) , set up a proper DAO , wire up the EntityManager or directly the SessionFactory (which is breaking the abstract JPA contract , but you can utilize the full goodies that hibernates offers) and then return the same object, but only with the columns you need.
Example for the second point:
import javax.persistence.EntityManager;
import org.hibernate.query.Query;
import org.hibernate.transform.Transformers;
public CustomEntity getEntity(){
Query<CustomEntity> q = (Query<CustomEntity>) entityManager.createQuery("select
e.id,e.name from CustomEntity e where e.name = 'parameter'");
q.setResultTransformer(Transformers.aliasToBean(CustomEntity.class));
CustomEntity entity = (CustomEntity) q.getSingleResult();
return name;
}
Note CustomEntity is a managed Entity Bean / Table in the database , just placing this example to be close on what you might need to achieve.
Tried with
Spring boot 2.0.5.RELEASE
Spring Data 2.0.5.RELEASE
Hibernate-core 5.2.17.Final

I tried a different solution today. Lets look at the code first.
Genre
#Data
#Entity
#Table(name = "genre")
public class Genre {
#Id
#SequenceGenerator(name = "genreSeq", sequenceName = "genre_id_seq",
allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "genreSeq")
private Integer id;
private String name;
#ManyToMany
#JoinTable(
name = "anime_genre",
joinColumns = #JoinColumn(name = "genre_id", referencedColumnName = "id"),
inverseJoinColumns = #JoinColumn(name = "details_id", referencedColumnName = "id"))
List<AnimeIdentity> animes;
protected Genre() {
}
}
AnimeIdentity
#Getter
#Setter
#Entity
#Table(name = "anime_details")
public class AnimeIdentity {
#Id
#SequenceGenerator(name = "animeDetailsSeq", sequenceName =
"anime_details_id_seq",
allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator =
"animeDetailsSeq")
private Integer id;
private String name;
protected AnimeIdentity() {};
}
Queries Hibernate made
Hibernate: select genre0_.id as id1_2_0_, genre0_.name as name2_2_0_ from genre genre0_ where genre0_.id=?<br>
Hibernate: select animes0_.genre_id as genre_id2_1_0_, animes0_.details_id as details_1_1_0_, animeident1_.id as id1_0_1_, animeident1_.name as name2_0_1_ from anime_genre animes0_ inner join anime_details animeident1_ on animes0_.details_id=animeident1_.id where animes0_.genre_id=?
Feel free to show me the pros and cons of this solution. To me its a good solution if my necessity is limited to only this. But in case of different type of queries making more and more entity pojos will be a tiresome task.

Hibernate and JSON - is there a definitive solution to circular dependencies?

I'm struggling with Hibernate entities and JSON in these days and, although there is a lot of questions regarding the object, I'm yet not capable to serialize in presence of circular dependencies. I tried with both Gson and jackson but I didn't get a lot of progresses.
Here is an excerpt from my objects.
This is the "parent" class.
#Entity
public class User extends RecognizedServerEntities implements java.io.Serializable
{
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Integer id;
#OneToMany(fetch = FetchType.LAZY, mappedBy = "user", orphanRemoval = false)
#Cascade({CascadeType.SAVE_UPDATE})
private Set<Thread> threads = new HashSet<Thread>(0);
//...other attributes, getters and setters
}
and this is the "children" class
#Entity
#Table(name = "thread")
public class Thread extends RecognizedServerEntities implements java.io.Serializable
{
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Integer id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "author", nullable = true)
private User user;
//...other attributes, getters and setters
}
I've written a simple class to test both gson and jackson features; as said, they both raise an exception.
public class MyJsonsTest
{
private static User u;
public static void main(String[] args)
{
u = new User("mail", "password", "nickname", new Date());
u.setId(1); // Added with EDIT 1
// testGson();
testJackson();
}
private static void testJackson()
{
Thread t = new Thread("Test", u, new Date(), new Date());
t.setId(1); // Added with EDIT 1
u.getThreads().add(t);
ObjectMapper mapper = new ObjectMapper();
mapper.enable(SerializationFeature.INDENT_OUTPUT);
try
{
mapper.writeValue(new File("result.json"), u);
}
catch {/[various exceptions catched, but a JsonMappingException was thrown]}
}
private static void testGson()
{
Gson gson = new Gson();
System.out.println(u.toString());
System.out.println(gson.toJson(u, User.class));
Thread t = new Thread("Test", u, new Date(), new Date());
u.getThreads().add(t);
//This raise an exception overflow
System.out.println(gson.toJson(u, User.class));
}
}
To solve the problem, on jackson side, I tried to use this annotation
#JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id")
on both User and Thread class. However, it doesn't solve the problem.
On gson side, I read about the GraphAdapterBuilder class, but I wasn't able to properly use it. I don't find any jar, so I copy/pasted the source code from here. However, there is a compile time error at this line
private final ConstructorConstructor constructorConstructor = new ConstructorConstructor();
because the ConstructorConstructor() is undefined; the right syntax should be
ConstructorConstructor(Map<Type>, InstanceCreator<?> instanceCreators)
So, is there a definitive solution to this problem? Obviously, I can't use transient variables.
EDIT 1
I finally found the issue with jackson. In the test class, I forgot to initialize the id field (in real scenarios it is initialized by the database) and this is the reason of the exception. When I finally set the id, all works. This is the output
{
"id" : 1,
"email" : "mail",
"password" : "password",
"nick" : "nickname",
"registeredDate" : 1414703168409,
"threads" : [ {
"id" : 1,
"thread" : null,
"user" : 1,
"title" : "Test",
"lastModifiedDate" : 1414703168410,
"createdDate" : 1414703168410,
"messages" : [ ],
"threads" : [ ]
} ],
"messages" : [ ]
}

When dealing with circular dependencies you need to build a parent-children JSON hierarchy, because the marshalling must be cascaded from root to the inner-most child.
For bi-directional associations, when the Parent has a one-to-many children collection and the child has a many-to-one reference to Parent, you need to annotate the many-to-one side with #JsonIgnore:
#Entity
#Table(name = "thread")
public class Thread extends RecognizedServerEntities implements java.io.Serializable
{
#Id
#GeneratedValue(strategy = IDENTITY)
#Column(name = "id", unique = true, nullable = false)
private Integer id;
#org.codehaus.jackson.annotate.JsonIgnore
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "author", nullable = true)
private User user;
//...other attributes, getters and setters
}
This way you will no longer have a Json serializing-time circular dependency.

Jackson
As said, I was able to solve the problem using
#JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id", scope=MyEntity.class)`
for each entity as suggested here.
The scope attribute was necessary to make sure that the name "id" is unique within the scope. Actually, without the scope attribute, as you can see here, it throws an exception saying
com.fasterxml.jackson.databind.JsonMappingException: Already had POJO for id java.lang.String) [com.fasterxml.jackson.annotation.ObjectIdGenerator$IdKey#3372bb3f] (through reference chain: ParentEntity["children"]->java.util.ArrayList[0]->ChildEntity["id"])
...stacktrace...
Caused by: java.lang.IllegalStateException: Already had POJO for id (java.lang.String) [com.fasterxml.jackson.annotation.ObjectIdGenerator$IdKey#3372bb3f]
...stacktrace...
Gson
I still haven't found a clean way to serialize circular dependencies.

I have done this using org.codehaus.jackson.annotate.JsonManagedReference and org.codehaus.jackson.annotate.JsonBackReference in this way...
look at how i used #JsonManagedReference
#Id
#TableGenerator(name="CatId", table="catTable",pkColumnName="catKey",pkColumnValue="catValue", allocationSize=1)
#GeneratedValue(strategy=GenerationType.TABLE, generator="CatId")
#Column(name = "CategId", unique = true, nullable = false)
private long categoryId;
private String productCategory;
#JsonManagedReference("product-category")
#OneToMany(targetEntity=ProductDatabase.class,mappedBy="category", cascade=CascadeType.ALL, fetch=FetchType.EAGER)
private List<ProductDatabase> catProducts;
and then at the other end i used #JsonBackReference as shown below.
#Id#GeneratedValue
private int productId;
private String description;
private int productPrice;
private String productName;
private String ProductImageURL;
#JsonBackReference("product-category")
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "CategId")
private Category category;
just apply these annotations and check if it works for you.

Its not good design to serialize Hibernate POJO to client. As you may send some data to client location, which he is not authorize to view. You should create client POJO and copy data from hibernate POJO to client POJO, which you want to send to client. If you don't want to do that, you can use #JsonIgnore or Fetch all data eagerly.

Hibernate #Any annotation usage

I have one entity called Change where I need log changes in database like inserting, updating or deleting rows.
So my Change table contains some data and now I would like to add foreign key to record changes in another table, but I have different tables. For example I have Weather table, Group table,... So I have done some searching and I have found a little bit about #Any annotation. So I added some columns to my Change entity:
#Entity
#Table(name = "CHANGE")
public class Change {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "CHANGE_ID")
private int changeId;
...
#Any(metaColumn = #Column(name = "RECORD_TABLE"))
#AnyMetaDef(idType = "int", metaType = "string",
metaValues = {
#MetaValue(targetEntity = Weather.class, value = "WEATHER"),
#MetaValue(targetEntity = Group.class, value = "GROUP"),
...
})
#JoinColumn(name="recordID")
private Object record;
#ManyToOne
#JoinColumn(name = "USER_ID")
private User user;
public Object getRecord() {
return record;
}
public void setRecord(Object record) {
this.record = record;
}
...
And my stupid question is:
How can I insert data into database (like foreign ID and class name) and how could I retrieve them?

Please go through this Link
You should care about your entity relationship (1-1 or 1-M or M-M)