| 1 | /* |
| 2 | * Copyright 2006-2007 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.springframework.batch.retry.policy; |
| 18 | |
| 19 | import org.springframework.batch.retry.RetryCallback; |
| 20 | import org.springframework.batch.retry.RetryContext; |
| 21 | import org.springframework.batch.retry.RetryPolicy; |
| 22 | import org.springframework.batch.retry.TerminatedRetryException; |
| 23 | import org.springframework.batch.retry.context.RetryContextSupport; |
| 24 | |
| 25 | /** |
| 26 | * A {@link RetryPolicy} that allows the first attempt but never permits a |
| 27 | * retry. Also be used as a base class for other policies, e.g. for test |
| 28 | * purposes as a stub. |
| 29 | * |
| 30 | * @author Dave Syer |
| 31 | * |
| 32 | */ |
| 33 | public class NeverRetryPolicy extends AbstractStatelessRetryPolicy { |
| 34 | |
| 35 | /** |
| 36 | * Returns false after the first exception. So there is always one try, and |
| 37 | * then the retry is prevented. |
| 38 | * |
| 39 | * @see org.springframework.batch.retry.RetryPolicy#canRetry(org.springframework.batch.retry.RetryContext) |
| 40 | */ |
| 41 | public boolean canRetry(RetryContext context) { |
| 42 | return !((NeverRetryContext) context).isFinished(); |
| 43 | } |
| 44 | |
| 45 | /** |
| 46 | * Do nothing. |
| 47 | * |
| 48 | * @see org.springframework.batch.retry.RetryPolicy#close(org.springframework.batch.retry.RetryContext) |
| 49 | */ |
| 50 | public void close(RetryContext context) { |
| 51 | // no-op |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * Return a context that can respond to early termination requests, but does |
| 56 | * nothing else. |
| 57 | * |
| 58 | * @see org.springframework.batch.retry.RetryPolicy#open(org.springframework.batch.retry.RetryCallback, RetryContext) |
| 59 | */ |
| 60 | public RetryContext open(RetryCallback callback, RetryContext parent) { |
| 61 | return new NeverRetryContext(parent); |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Do nothing. |
| 66 | * @see org.springframework.batch.retry.RetryPolicy#registerThrowable(org.springframework.batch.retry.RetryContext, |
| 67 | * java.lang.Throwable) |
| 68 | */ |
| 69 | public void registerThrowable(RetryContext context, Throwable throwable) throws TerminatedRetryException { |
| 70 | ((NeverRetryContext) context).setFinished(); |
| 71 | ((RetryContextSupport) context).registerThrowable(throwable); |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Special context object for {@link NeverRetryPolicy}. Implements a flag |
| 76 | * with a similar function to {@link RetryContext#isExhaustedOnly()}, but |
| 77 | * kept separate so that if subclasses of {@link NeverRetryPolicy} need to |
| 78 | * they can modify the behaviour of |
| 79 | * {@link NeverRetryPolicy#canRetry(RetryContext)} without affecting |
| 80 | * {@link RetryContext#isExhaustedOnly()}. |
| 81 | * |
| 82 | * @author Dave Syer |
| 83 | * |
| 84 | */ |
| 85 | private static class NeverRetryContext extends RetryContextSupport { |
| 86 | private boolean finished = false; |
| 87 | |
| 88 | public NeverRetryContext(RetryContext parent) { |
| 89 | super(parent); |
| 90 | } |
| 91 | |
| 92 | public boolean isFinished() { |
| 93 | return finished; |
| 94 | } |
| 95 | |
| 96 | public void setFinished() { |
| 97 | this.finished = true; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | } |