How to Generate an auto UUID using Hibernate on spring boot

问题

What I am trying to achieve is generate a UUID which is automatically assigned during a DB Insert. Similar to the primary key column named "id" generating an id value.

The model values looks something like this:

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(nullable = false)
private Long id;


@GeneratedValue(generator = "uuid2")
@GenericGenerator(name = "uuid2", strategy = "uuid2")
@Column(name = "uuid", columnDefinition = "BINARY(16)")
private UUID uuid;

But when the DB insert is done. the "uuid" is empty.

Help is greatly appreciated. And if I am asking an obvious stupid question I am sorry.

回答1:

u could use some events like @PrePersist to populate UUID field https://docs.jboss.org/hibernate/orm/4.0/hem/en-US/html/listeners.html

but why just not assign uuid when object is created uuid = UUID.randomUUID() ?

回答2:

Can you try?

    @Id
    @GeneratedValue(generator = "uuid2")
    @GenericGenerator(name = "uuid2", strategy = "org.hibernate.id.UUIDGenerator")
    @Column(name = "id", columnDefinition = "VARCHAR(255)")
    private UUID id;

回答3:

Following worked for me:

@Id
    @GeneratedValue(generator = "UUID")
    @GenericGenerator(
            name = "UUID",
            strategy = "org.hibernate.id.UUIDGenerator"
    )
    @Column(name = "id", updatable = false, nullable = false)
    private UUID id;

来源：https://stackoverflow.com/questions/45086957/how-to-generate-an-auto-uuid-using-hibernate-on-spring-boot