Spring data jpa save can not get id

1. You should use the repository.saveAndFlush(); method:

MyObject savedObject= repository.saveAndFlush(newObject);

2. In the Entity object description, you should add the following attribute(@GeneratedValue(strategy = GenerationType.AUTO)) to the related field(id):

@Id   
@Column(name = "id")   
@GeneratedValue(strategy = GenerationType.AUTO)   
public long getId() {  
    return id;  
}

I believe this post answers your question:

Why to use returned instance after save() on Spring Data JPA Repository?

The repository.save() method actually returns a new object like JPA entityManager.merge() and the returned object is the one that will have the ID set.

Try this like

myboject = repository.save(myboject);
repository.flush();

Then after call to getId();

This method returns the saved id

myobject = repository.saveAndFlush(myobject);

Now you have your id.