How to map byte[] to jdbc BINARY type?

It’s actually very simple.

Since version 2.10.1, you can use the MySQLBinaryType from the Hibernate Types project, so your mapping looks like this:

@Entity
@TypeDef(
	typeClass = MySQLBinaryType.class, 
	defaultForType = byte[].class
)
public class Post {

	@Id
	@GeneratedValue
	private Long id;

	private String title;

	@Column
	private byte[] image;
	
	...
}

Here you can see an example on GitHub that works like a charm.