| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| * |
| */ |
| |
| package org.apache.qpid.client.failover; |
| |
| import org.apache.qpid.client.AMQConnection; |
| |
| /** |
| * FailoverNoopSupport is a {@link FailoverSupport} implementation that does not really provide any failover support |
| * at all. It wraps a {@link FailoverProtectedOperation} but should that operation throw {@link FailoverException} this |
| * support class simply re-raises that exception as an IllegalStateException. This support wrapper should only be |
| * used where the caller can be certain that the failover protected operation cannot acutally throw a failover exception, |
| * for example, because the caller already holds a lock preventing that condition from arising. |
| * |
| * <p><table id="crc"><caption>CRC Card</caption> |
| * <tr><th> Responsibilities <th> Collaborations |
| * <tr><td> Perform a fail-over protected operation raising providing no handling of fail-over conditions. |
| * </table> |
| */ |
| public class FailoverNoopSupport<T, E extends Exception> implements FailoverSupport<T, E> |
| { |
| /** The protected operation that is to be retried in the event of fail-over. */ |
| private FailoverProtectedOperation<T, E> operation; |
| |
| /** The connection on which the fail-over protected operation is to be performed. */ |
| private AMQConnection connection; |
| |
| /** |
| * Creates an automatic retrying fail-over handler for the specified operation. |
| * |
| * @param operation The fail-over protected operation to wrap in this handler. |
| */ |
| public FailoverNoopSupport(FailoverProtectedOperation<T, E> operation, AMQConnection con) |
| { |
| this.operation = operation; |
| this.connection = con; |
| } |
| |
| /** |
| * Delegates to another continuation which is to be provided with fail-over handling. |
| * |
| * @return The return value from the delegated to continuation. |
| * @throws E Any exception that the delegated to continuation may raise. |
| */ |
| public T execute() throws E |
| { |
| try |
| { |
| return operation.execute(); |
| } |
| catch (FailoverException e) |
| { |
| throw new IllegalStateException("Fail-over interupted no-op failover support. " |
| + "No-op support should only be used where the caller is certain fail-over cannot occur.", e); |
| } |
| } |
| } |