I am using java mail in servlet. I have use ENCTYPE= "multipart/form-data" method for getting information from user. I am also accepting file attachment from user. This information was parse successfully. I have use byte[] for storing contains of attach file. I have write following code for adding contains of the file to Mime part.

			

			

			Multipart mp = new MimeMultipart();
			

			MimeBodyPart mbp = new MimeBodyPart();
			

			

			// filehashtable is Hashtable used for storing files detail
			

			

			String filename = (String)filehashtable("filename");
			

			byte buf[] = (byte[]) filehashtable.get("content");
			

			String contype = (String)filehashtable.get("content-type");
			

			

			mbp.setDataHandler(new DataHandler(new String(buf),contype));
			

			mbp.setFileName(filename);
			

			mp.addBodyPart(mbp);
			

			

		

The above code is running successfully when attachment file is of type "text/html", but

if attachment is .zip file then, i got following exception

Sending failed; nested exception is: javax.mail.MessagingException: IOException while sending message; nested exception is: javax.activation.UnsupportedDataTypeException: no object DCH for MIME type application/x-zip-compressed

if attachment if .gif file then, i got following exception

Sending failed; nested exception is: javax.mail.MessagingException: IOException while sending message; nested exception is: javax.activation.UnsupportedDataTypeException: no object DCH for MIME type image/gif

I want to know what is the problem. What is more require for handling this. I have also tested the contains of the file by writing it some other location. It is ok.