hi, help me发送byte[]附件的问题

hi, help me发送byte[]附件的问题
the excpetion is :
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javax.mail.SendFailedException: Sending failed;
nested exception is:
javax.mail.MessagingException: IOException while sending message;
nested exception is:
java.io.IOException: No content
at javax.mail.Transport.send0(Transport.java:219)
at javax.mail.Transport.send(Transport.java:81)
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i retrive the attachment from the blob type filed in oracle db.
but when i send it , the above error occurs

below is my send code;

DataSource ds = new BufferedDataSource(b, filename);
bodyPart.setDataHandler( new DataHandler( new ByteArrayDataSource(b, "application/octet-stream",filename ) ) );
bodyPart.setFileName(filename);
multipart.addBodyPart(messageBodyPart);


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b is a byte array

any one can help me , thanks in advance
beijing,
china