How to convert Part to Blob, so I can store it in MySQL?

Question

How to convert Part to Blob, so I can store it in MySQL? It is an image. Thank you

My form

Answer 1

The SQL database BLOB type is in Java represented as byte[]. This is in JPA further to be annotated as @Lob. So, your model basically need to look like this:

@Entity
public class SomeEntity {

    @Lob
    private byte[] image;

    // ...
}

As to dealing with Part, you thus basically need to read its InputStream into a byte[]. Apache Commons IO IOUtils is helpful here:

InputStream input = uploadedFile.getInputStream();
byte[] image = IOUtils.toByteArray(input); // Apache commons IO.
someEntity.setImage(image);
// ...

Or if you prefer standard Java API which is only a bit more verbose:

InputStream input = uploadedFile.getInputStream();
ByteArrayOutputStream output = new ByteArrayOutputStream();
byte[] buffer = new byte[10240];
for (int length = 0; (length = input.read(buffer)) > 0;) output.write(buffer, 0, length);
someEntity.setImage(output.toByteArray());
// ...