1 /*******************************************************************************
2 * Copyright (c) 2010, 2014 Sonatype, Inc.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * Sonatype, Inc. - initial API and implementation
10 *******************************************************************************/
11 package org.eclipse.aether.transfer;
12
13 /**
14 * A listener being notified of artifact/metadata transfers from/to remote repositories. The listener may be called from
15 * an arbitrary thread. Reusing common regular expression syntax, the sequence of events is roughly as follows:
16 *
17 * <pre>
18 * INITIATED ( STARTED PROGRESSED* CORRUPTED? )* ( SUCCEEDED | FAILED )
19 * </pre>
20 *
21 * <em>Note:</em> Implementors are strongly advised to inherit from {@link AbstractTransferListener} instead of directly
22 * implementing this interface.
23 *
24 * @see org.eclipse.aether.RepositorySystemSession#getTransferListener()
25 * @see org.eclipse.aether.RepositoryListener
26 * @noimplement This interface is not intended to be implemented by clients.
27 * @noextend This interface is not intended to be extended by clients.
28 */
29 public interface TransferListener
30 {
31
32 /**
33 * Notifies the listener about the initiation of a transfer. This event gets fired before any actual network access
34 * to the remote repository and usually indicates some thread is now about to perform the transfer. For a given
35 * transfer request, this event is the first one being fired and it must be emitted exactly once.
36 *
37 * @param event The event details, must not be {@code null}.
38 * @throws TransferCancelledException If the transfer should be aborted.
39 */
40 void transferInitiated( TransferEvent event )
41 throws TransferCancelledException;
42
43 /**
44 * Notifies the listener about the start of a data transfer. This event indicates a successful connection to the
45 * remote repository. In case of a download, the requested remote resource exists and its size is given by
46 * {@link TransferResource#getContentLength()} if possible. This event may be fired multiple times for given
47 * transfer request if said transfer needs to be repeated (e.g. in response to an authentication challenge).
48 *
49 * @param event The event details, must not be {@code null}.
50 * @throws TransferCancelledException If the transfer should be aborted.
51 */
52 void transferStarted( TransferEvent event )
53 throws TransferCancelledException;
54
55 /**
56 * Notifies the listener about some progress in the data transfer. This event may even be fired if actually zero
57 * bytes have been transferred since the last event, for instance to enable cancellation.
58 *
59 * @param event The event details, must not be {@code null}.
60 * @throws TransferCancelledException If the transfer should be aborted.
61 */
62 void transferProgressed( TransferEvent event )
63 throws TransferCancelledException;
64
65 /**
66 * Notifies the listener that a checksum validation failed. {@link TransferEvent#getException()} will be of type
67 * {@link ChecksumFailureException} and can be used to query further details about the expected/actual checksums.
68 *
69 * @param event The event details, must not be {@code null}.
70 * @throws TransferCancelledException If the transfer should be aborted.
71 */
72 void transferCorrupted( TransferEvent event )
73 throws TransferCancelledException;
74
75 /**
76 * Notifies the listener about the successful completion of a transfer. This event must be fired exactly once for a
77 * given transfer request unless said request failed.
78 *
79 * @param event The event details, must not be {@code null}.
80 */
81 void transferSucceeded( TransferEvent event );
82
83 /**
84 * Notifies the listener about the unsuccessful termination of a transfer. {@link TransferEvent#getException()} will
85 * provide further information about the failure.
86 *
87 * @param event The event details, must not be {@code null}.
88 */
89 void transferFailed( TransferEvent event );
90
91 }