| 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.repeat.policy; |
| 18 | |
| 19 | import org.springframework.batch.repeat.RepeatContext; |
| 20 | import org.springframework.batch.repeat.context.RepeatContextSupport; |
| 21 | |
| 22 | /** |
| 23 | * Termination policy that times out after a fixed period. Allows graceful exit |
| 24 | * from a batch if the latest result comes in after the timeout expires (i.e. |
| 25 | * does not throw a timeout exception).<br/> |
| 26 | * |
| 27 | * N.B. It may often be the case that the batch governed by this policy will be |
| 28 | * transactional, and the transaction might have its own timeout. In this case |
| 29 | * the transaction might throw a timeout exception on commit if its timeout |
| 30 | * threshold is lower than the termination policy. |
| 31 | * |
| 32 | * @author Dave Syer |
| 33 | * |
| 34 | */ |
| 35 | public class TimeoutTerminationPolicy extends CompletionPolicySupport { |
| 36 | |
| 37 | /** |
| 38 | * Default timeout value in millisecs (the value equivalent to 30 seconds). |
| 39 | */ |
| 40 | public static final long DEFAULT_TIMEOUT = 30000L; |
| 41 | |
| 42 | private long timeout = DEFAULT_TIMEOUT; |
| 43 | |
| 44 | /** |
| 45 | * Default constructor. |
| 46 | */ |
| 47 | public TimeoutTerminationPolicy() { |
| 48 | super(); |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * Construct a {@link TimeoutTerminationPolicy} with the specified timeout |
| 53 | * value (in milliseconds). |
| 54 | * |
| 55 | * @param timeout |
| 56 | */ |
| 57 | public TimeoutTerminationPolicy(long timeout) { |
| 58 | super(); |
| 59 | this.timeout = timeout; |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Check the timeout and complete gracefully if it has expires. |
| 64 | * |
| 65 | * @see org.springframework.batch.repeat.CompletionPolicy#isComplete(org.springframework.batch.repeat.RepeatContext) |
| 66 | */ |
| 67 | public boolean isComplete(RepeatContext context) { |
| 68 | return ((TimeoutBatchContext) context).isComplete(); |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * Start the clock on the timeout. |
| 73 | * |
| 74 | * @see org.springframework.batch.repeat.CompletionPolicy#start(RepeatContext) |
| 75 | */ |
| 76 | public RepeatContext start(RepeatContext context) { |
| 77 | return new TimeoutBatchContext(context); |
| 78 | } |
| 79 | |
| 80 | protected class TimeoutBatchContext extends RepeatContextSupport { |
| 81 | |
| 82 | private volatile long time = System.currentTimeMillis(); |
| 83 | |
| 84 | private final long timeout = TimeoutTerminationPolicy.this.timeout; |
| 85 | |
| 86 | public TimeoutBatchContext(RepeatContext context) { |
| 87 | super(context); |
| 88 | } |
| 89 | |
| 90 | public boolean isComplete() { |
| 91 | return (System.currentTimeMillis() - time) > timeout; |
| 92 | } |
| 93 | |
| 94 | } |
| 95 | |
| 96 | } |