Java tutorial
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If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package javax.mail.internet; import javax.mail.*; import javax.activation.*; import java.io.*; import java.net.UnknownServiceException; import com.sun.mail.util.PropUtil; import com.sun.mail.util.FolderClosedIOException; /** * A utility class that implements a DataSource out of * a MimePart. This class is primarily meant for service providers. * * @see javax.mail.internet.MimePart * @see javax.activation.DataSource * @author John Mani */ public class MimePartDataSource implements DataSource, MessageAware { /** * The MimePart that provides the data for this DataSource. * * @since JavaMail 1.4 */ protected MimePart part; private MessageContext context; /** * Constructor, that constructs a DataSource from a MimePart. * * @param part the MimePart */ public MimePartDataSource(MimePart part) { this.part = part; } /** * Returns an input stream from this MimePart. <p> * * This method applies the appropriate transfer-decoding, based * on the Content-Transfer-Encoding attribute of this MimePart. * Thus the returned input stream is a decoded stream of bytes.<p> * * This implementation obtains the raw content from the Part * using the <code>getContentStream()</code> method and decodes * it using the <code>MimeUtility.decode()</code> method. * * @see javax.mail.internet.MimeMessage#getContentStream * @see javax.mail.internet.MimeBodyPart#getContentStream * @see javax.mail.internet.MimeUtility#decode * @return decoded input stream */ @Override public InputStream getInputStream() throws IOException { InputStream is; try { if (part instanceof MimeBodyPart) is = ((MimeBodyPart) part).getContentStream(); else if (part instanceof MimeMessage) is = ((MimeMessage) part).getContentStream(); else throw new MessagingException("Unknown part"); String encoding = MimeBodyPart.restrictEncoding(part, part.getEncoding()); if (encoding != null) return MimeUtility.decode(is, encoding); else return is; } catch (FolderClosedException fex) { throw new FolderClosedIOException(fex.getFolder(), fex.getMessage()); } catch (MessagingException mex) { IOException ioex = new IOException(mex.getMessage()); ioex.initCause(mex); throw ioex; } } /** * DataSource method to return an output stream. <p> * * This implementation throws the UnknownServiceException. */ @Override public OutputStream getOutputStream() throws IOException { throw new UnknownServiceException("Writing not supported"); } /** * Returns the content-type of this DataSource. <p> * * This implementation just invokes the <code>getContentType</code> * method on the MimePart. */ @Override public String getContentType() { try { return part.getContentType(); } catch (MessagingException mex) { // would like to be able to reflect the exception to the // application, but since we can't do that we return a // generic "unknown" value here and hope for another // exception later. return "application/octet-stream"; } } /** * DataSource method to return a name. <p> * * This implementation just returns an empty string. */ @Override public String getName() { try { if (part instanceof MimeBodyPart) return ((MimeBodyPart) part).getFileName(); } catch (MessagingException mex) { // ignore it } return ""; } /** * Return the <code>MessageContext</code> for the current part. * @since JavaMail 1.1 */ @Override public synchronized MessageContext getMessageContext() { if (context == null) context = new MessageContext(part); return context; } }