01 /*
02 * Licensed to the Apache Software Foundation (ASF) under one
03 * or more contributor license agreements. See the NOTICE file
04 * distributed with this work for additional information
05 * regarding copyright ownership. The ASF licenses this file
06 * to you under the Apache License, Version 2.0 (the
07 * "License"); you may not use this file except in compliance
08 * with the License. You may obtain a copy of the License at
09 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 *
20 */
21
22 package org.apache.qpid.client.failover;
23
24 /**
25 * FailoverProtectedOperation is a continuation for an operation that may throw a {@link FailoverException} because
26 * it has been interrupted by the fail-over process. The {@link FailoverRetrySupport} class defines support wrappers
27 * for failover protected operations, in order to provide different handling schemes when failovers occurr.
28 *
29 * <p/>The type of checked exception that the operation may perform has been generified, in order that fail over
30 * protected operations can be defined that raise arbitrary exceptions. The actuall exception types used should not
31 * be sub-classes of FailoverException, or else catching FailoverException in the {@link FailoverRetrySupport} classes
32 * will mask the exception.
33 *
34 * <p><table id="crc"><caption>CRC Card</caption>
35 * <tr><th> Responsibilities
36 * <tr><td> Perform an operation that may be interrupted by fail-over.
37 * </table>
38 */
39 public interface FailoverProtectedOperation<T, E extends Exception>
40 {
41 /**
42 * Performs the continuations work.
43 *
44 * @return Provdes scope for the continuation to return an arbitrary value.
45 *
46 * @throws FailoverException If the operation is interrupted by a fail-over notification.
47 */
48 public abstract T execute() throws E, FailoverException;
49 }
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