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; import java.util.NoSuchElementException; /** * The <code>UIDFolder</code> interface is implemented by Folders * that can support the "disconnected" mode of operation, by providing * unique-ids for messages in the folder. This interface is based on * the IMAP model for supporting disconnected operation. <p> * * A Unique identifier (UID) is a positive long value, assigned to * each message in a specific folder. Unique identifiers are assigned * in a strictly <strong>ascending</strong> fashion in the mailbox. * That is, as each message is added to the mailbox it is assigned a * higher UID than the message(s) which were added previously. Unique * identifiers persist across sessions. This permits a client to * resynchronize its state from a previous session with the server. <p> * * Associated with every mailbox is a unique identifier validity value. * If unique identifiers from an earlier session fail to persist to * this session, the unique identifier validity value * <strong>must</strong> be greater than the one used in the earlier * session. <p> * * Refer to <A HREF="http://www.ietf.org/rfc/rfc2060.txt">RFC 2060</A> * for more information. * * All the Folder objects returned by the default IMAP provider implement * the UIDFolder interface. Use it as follows: * <blockquote><pre> * * Folder f = store.getFolder("whatever"); * UIDFolder uf = (UIDFolder)f; * long uid = uf.getUID(msg); * * </pre></blockquote><p> * * @author Bill Shannon * @author John Mani */ public interface UIDFolder { /** * A fetch profile item for fetching UIDs. * This inner class extends the <code>FetchProfile.Item</code> * class to add new FetchProfile item types, specific to UIDFolders. * The only item currently defined here is the <code>UID</code> item. * * @see FetchProfile */ public static class FetchProfileItem extends FetchProfile.Item { protected FetchProfileItem(String name) { super(name); } /** * UID is a fetch profile item that can be included in a * <code>FetchProfile</code> during a fetch request to a Folder. * This item indicates that the UIDs for messages in the specified * range are desired to be prefetched. <p> * * An example of how a client uses this is below: * <blockquote><pre> * * FetchProfile fp = new FetchProfile(); * fp.add(UIDFolder.FetchProfileItem.UID); * folder.fetch(msgs, fp); * * </pre></blockquote> */ public static final FetchProfileItem UID = new FetchProfileItem("UID"); } /** * This is a special value that can be used as the <code>end</code> * parameter in <code>getMessagesByUID(start, end)</code>, to denote the * UID of the last message in the folder. * * @see #getMessagesByUID */ public static final long LASTUID = -1; /** * The largest value possible for a UID, a 32-bit unsigned integer. * This can be used to fetch all new messages by keeping track of the * last UID that was seen and using: * <blockquote><pre> * * Folder f = store.getFolder("whatever"); * UIDFolder uf = (UIDFolder)f; * Message[] newMsgs = * uf.getMessagesByUID(lastSeenUID + 1, UIDFolder.MAXUID); * * </pre></blockquote><p> * * @since JavaMail 1.6 */ public static final long MAXUID = 0xffffffffL; // max 32-bit unsigned int /** * Returns the UIDValidity value associated with this folder. <p> * * Clients typically compare this value against a UIDValidity * value saved from a previous session to insure that any cached * UIDs are not stale. * * @return UIDValidity * @exception MessagingException for failures */ public long getUIDValidity() throws MessagingException; /** * Get the Message corresponding to the given UID. If no such * message exists, <code>null</code> is returned. * * @param uid UID for the desired message * @return the Message object. <code>null</code> is returned * if no message corresponding to this UID is obtained. * @exception MessagingException for failures */ public Message getMessageByUID(long uid) throws MessagingException; /** * Get the Messages specified by the given range. The special * value LASTUID can be used for the <code>end</code> parameter * to indicate the UID of the last message in the folder. <p> * * Note that <code>end</code> need not be greater than <code>start</code>; * the order of the range doesn't matter. * Note also that, unless the folder is empty, use of LASTUID ensures * that at least one message will be returned - the last message in the * folder. * * @param start start UID * @param end end UID * @return array of Message objects * @exception MessagingException for failures * @see #LASTUID */ public Message[] getMessagesByUID(long start, long end) throws MessagingException; /** * Get the Messages specified by the given array of UIDs. If any UID is * invalid, <code>null</code> is returned for that entry. <p> * * Note that the returned array will be of the same size as the specified * array of UIDs, and <code>null</code> entries may be present in the * array to indicate invalid UIDs. * * @param uids array of UIDs * @return array of Message objects * @exception MessagingException for failures */ public Message[] getMessagesByUID(long[] uids) throws MessagingException; /** * Get the UID for the specified message. Note that the message * <strong>must</strong> belong to this folder. Otherwise * java.util.NoSuchElementException is thrown. * * @param message Message from this folder * @return UID for this message * @exception NoSuchElementException if the given Message * is not in this Folder. * @exception MessagingException for other failures */ public long getUID(Message message) throws MessagingException; /** * Returns the predicted UID that will be assigned to the * next message that is appended to this folder. * Messages might be appended to the folder after this value * is retrieved, causing this value to be out of date. * This value might only be updated when a folder is first opened. * Note that messages may have been appended to the folder * while it was open and thus this value may be out of * date. <p> * * If the value is unknown, -1 is returned. <p> * * @return the UIDNEXT value, or -1 if unknown * @exception MessagingException for failures * @since JavaMail 1.6 */ public long getUIDNext() throws MessagingException; }