Blob

Represents a binary large object.

Conceptually you can consider it as a set of bytes (a picture, a video etc), though in fact it wraps three pieces of information:

the set of bytes
a name
a mime type

API

Blob.java

class Blob {
  Blob(final String name, final String primaryType, final String subtype, final byte[] bytes)
  Blob(final String name, final String mimeTypeBase, final byte[] bytes)
  Blob(final String name, final MimeType mimeType, final byte[] bytes)
  Blob of(final String name, final CommonMimeType mimeType, final byte[] content)     (1)
  String getName()
  MimeType getMimeType()
  byte[] getBytes()
  Clob toClob(final Charset charset)
  void writeBytesTo(final OutputStream os)     (2)
  void consume(final Consumer<InputStream> consumer)     (3)
  R digest(final Function<InputStream, R> digester)     (4)
  Blob zip()
  Blob unZip(final CommonMimeType resultingMimeType)
  boolean equals(final Object o)
  int hashCode()
  String toString()
  Optional<BufferedImage> asImage()     (5)
}

1	[of__String_CommonMimeType_byte][of(String, CommonMimeType, byte[])] Returns a new Blob of given name , mimeType and content .
2	writeBytesTo(OutputStream) Does not close the OutputStream.
3	consume(Consumer) The InputStream involved is closed after consumption.
4	digest(Function) The InputStream involved is closed after digestion.
5	asImage()

Members

of(String, CommonMimeType, byte[])

Returns a new Blob of given name , mimeType and content .

name may or may not include the desired filename extension, it is guaranteed, that the resulting Blob has the appropriate extension as constraint by the given mimeType .

For more fine-grained control use one of the Blob constructors directly.

writeBytesTo(OutputStream)

Does not close the OutputStream.

consume(Consumer)

The InputStream involved is closed after consumption.

digest(Function)

The InputStream involved is closed after digestion.

asImage()

Usage Notes

If using JDO/DataNucleus, Blob properties can be mapped using:

@javax.jdo.annotations.Persistent(defaultFetchGroup="false")
    @javax.jdo.annotations.Persistent(defaultFetchGroup="false", columns = {
            @javax.jdo.annotations.Column(name = "attachment_name"),
            @javax.jdo.annotations.Column(name = "attachment_mimetype"),
            @javax.jdo.annotations.Column(name = "attachment_bytes", jdbcType = "BLOB", sqlType = "BLOB")
    })
@Property(optionality = Optionality.OPTIONAL)
@Getter @Setter
private Blob attachment;

If the property is mandatory, add allowsNull = "false for each of the @Columns.