Question

I have an Image class that has a byte[] to contain the actual image data. I’m able to upload and insert the image just fine in my webapp. When I attempt to display the image after reading it from JPA the length of my byte[] is always either 2x-1 or 2x-2, where x is the length of the bytea field in postgres 9. Obviously the browser won’t display the image saying it’s corrupted. I could use some help figuring out why I’m getting (about) twice what I expect. Here’s the mapping of my image class. Using eclipselink with JPA 2 hitting postgres 9 on a mac.

When I select from the database with

select *, length(bytes) from image;

I get a length of 9765. In a breakpoint in my controller the byte[] length is 19529 which is one byte shy of twice what’s in the database.

@Entity
@Table( name = "image" )
@SequenceGenerator( name = "IMAGE_SEQ_GEN", sequenceName = "IMAGE_SEQUENCE" )
public class Image
        extends DataObjectAbstract<Long>
{
    @Id
    @GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "IMAGE_SEQ_GEN" )
    private Long key;

    @Column( name="content_type" )
    private String contentType;

    @Lob
    @Basic( optional=false )
    @Column( name="bytes" )
    private byte[] bytes;

    // constructor and getters and setters

}

pgadmin shows me the following for the image table

CREATE TABLE image
(
  "key" bigint NOT NULL,
  bytes bytea,
  content_type character varying(255),
  "version" integer,
  CONSTRAINT image_pkey PRIMARY KEY (key)
)
WITH (
  OIDS=FALSE
);

Answer 1

In PostgreSQL 9 byte[] is sent to client using hex encoding.

If this is reason for error you have to find update for JPA.
Or you may change config of DB server but previous is better.