How to POST nested entities with Spring Data REST

I'm building a Spring Data REST application and I'm having some problems when I try to POST it. The main entity has other two related entities nested. There is a "questionary" object which has many answers and each one of these answers have many replies. I generate a JSON like this from the front application to POST the questionary: ``` { "user": "http://localhost:8080/users/1", "status": 1, "answers": [ { "img": "urlOfImg", "question": "http://localhost:8080/question/6", "replies": [ { "literal": "http://localhost:8080/literal/1", "result": "6" }, { "literal": "http://localhost:8080/literal/1", "result": "6" } ] }, { "img": "urlOfImg", "question": "http://localhost:8080/question/6", "replies": [ { "literal": "http://localhost:8080/literal/3", "result": "10" } ] } ] } ``` But when I try to post it, I get the follow error response: ``` { "cause" : { "cause" : { "cause" : null, "message" : "Template must not be null or empty!" }, "message" : "Template must not be null or empty! (through reference chain: project.models.Questionary[\"answers\"])" }, "message" : "Could not read JSON: Template must not be null or empty! (through reference chain: project.models.Questionary[\"answers\"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Template must not be null or empty! (through reference chain: project.models.Questionary[\"answers\"])" } ``` Edit: I also add my repository: ``` @RepositoryRestResource(collectionResourceRel = "questionaries", path = "questionaries") public interface InspeccionRepository extends JpaRepository<Inspeccion, Integer> { @RestResource(rel="byUser", path="byUser") public List<Questionary> findByUser (@Param("user") User user); } ``` My Entity Questionary class is : ``` @Entity @Table(name="QUESTIONARY", schema="enco" ) public class Questionary implements Serializable { private static final long serialVersionUID = 1L; //---------------------------------------------------------------------- // ENTITY PRIMARY KEY ( BASED ON A SINGLE FIELD ) //---------------------------------------------------------------------- @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEC_QUESTIONARY") @SequenceGenerator(name = "SEC_QUESTIONARY", sequenceName = "ENCO.SEC_QUESTIONARY", allocationSize = 1) @Column(name="IDQUES", nullable=false) private Integer idques ; //---------------------------------------------------------------------- // ENTITY DATA FIELDS //---------------------------------------------------------------------- @Column(name="ESTATUS") private Integer estatus ; //---------------------------------------------------------------------- // ENTITY LINKS ( RELATIONSHIP ) //---------------------------------------------------------------------- @ManyToOne @JoinColumn(name="IDUSER", referencedColumnName="IDUSER") private User user; @OneToMany(mappedBy="questionary", targetEntity=Answer.class) private List<Answer> answers; //---------------------------------------------------------------------- // CONSTRUCTOR(S) //---------------------------------------------------------------------- public Questionary() { super(); } //---------------------------------------------------------------------- // GETTERS & SETTERS FOR FIELDS //---------------------------------------------------------------------- //--- DATABASE MAPPING : IDNSE ( NUMBER ) public void setIdnse( Integer idnse ) { this.idnse = idnse; } public Integer getIdnse() { return this.idnse; } //--- DATABASE MAPPING : ESTADO ( NUMBER ) public void setEstatus Integer estatus ) { this.estatus = estatus; } public Integer getEstatus() { return this.estatus; } //---------------------------------------------------------------------- // GETTERS & SETTERS FOR LINKS //---------------------------------------------------------------------- public void setUser( Usuario user ) { this.user = user; } public User getUser() { return this.user; } public void setAnswers( List<Respuesta> answers ) { this.answers = answer; } public List<Answer> getAnswers() { return this.answers; } // Get Complete Object method public List<Answer> getAnswerComplete() { List<Answer> answers = this.answers; return answers; } } ``` My Answer Entity: ``` @Entity @Table(name="ANSWER", schema="enco" ) public class Answer implements Serializable { private static final long serialVersionUID = 1L; //---------------------------------------------------------------------- // ENTITY PRIMARY KEY ( BASED ON A SINGLE FIELD ) //---------------------------------------------------------------------- @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEC_ANSWER") @SequenceGenerator(name = "SEC_ANSWER", sequenceName = "ENCOADMIN.SEC_ANSWER", allocationSize = 1) @Column(name="IDANS", nullable=false) private Integer idans ; //---------------------------------------------------------------------- // ENTITY DATA FIELDS //---------------------------------------------------------------------- @Column(name="IMG", length=100) private String img ; //---------------------------------------------------------------------- // ENTITY LINKS ( RELATIONSHIP ) //---------------------------------------------------------------------- @ManyToOne @JoinColumn(name="IDQUES", referencedColumnName="IDQUES") private Questionary questionary ; @OneToMany(mappedBy="answer", targetEntity=Reply.class) private List<Reply> replies; @ManyToOne @JoinColumn(name="IDQUE", referencedColumnName="IDQUE") private Question Question ; //---------------------------------------------------------------------- // CONSTRUCTOR(S) //---------------------------------------------------------------------- public Answer() { super(); } //---------------------------------------------------------------------- // GETTER & SETTER FOR THE KEY FIELD //---------------------------------------------------------------------- public void setIdans( Integer idans ) { this.idans = idans ; } public Integer getIdans() { return this.idans; } //---------------------------------------------------------------------- // GETTERS & SETTERS FOR FIELDS //---------------------------------------------------------------------- //--- DATABASE MAPPING : IMAGEN ( VARCHAR2 ) public void setImg( String img ) { this.img = img; } public String getImg() { return this.img; } //---------------------------------------------------------------------- // GETTERS & SETTERS FOR LINKS //---------------------------------------------------------------------- public void setQuestionary( Questionary questionary ) { this.questionary = questionary; } public Questionary getQuestionary() { return this.questionary; } public void setReplies( List<Reply> contestaciones ) { this.replies = replies; } public List<Reply> getReplies() { return this.replies; } public void setQuestion( Question question ) { this.question = question; } public Question getQuestion() { return this.question; } } ``` And this is the error console: ``` Caused by: com.fasterxml.jackson.databind.JsonMappingException: Template must not be null or empty! (through reference chain: project.models.Questionary["answers"]) at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:232) ~[jackson-databind-2.3.3.jar:2.3.3] at *snip* ```