| 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.ExitStatus; |
| 20 | import org.springframework.batch.repeat.RepeatContext; |
| 21 | import org.springframework.batch.repeat.context.RepeatContextSupport; |
| 22 | import org.springframework.batch.repeat.support.RepeatTemplate; |
| 23 | |
| 24 | /** |
| 25 | * Policy for terminating a batch after a fixed number of operations. Internal |
| 26 | * state is maintained and a counter incremented, so successful use of this |
| 27 | * policy requires that isComplete() is only called once per batch item. Using |
| 28 | * the standard {@link RepeatTemplate} should ensure this contract is kept, but it needs |
| 29 | * to be carefully monitored. |
| 30 | * |
| 31 | * @author Dave Syer |
| 32 | * |
| 33 | */ |
| 34 | public class SimpleCompletionPolicy extends DefaultResultCompletionPolicy { |
| 35 | |
| 36 | public static final int DEFAULT_CHUNK_SIZE = 5; |
| 37 | |
| 38 | int chunkSize = 0; |
| 39 | |
| 40 | public SimpleCompletionPolicy() { |
| 41 | this(DEFAULT_CHUNK_SIZE); |
| 42 | } |
| 43 | |
| 44 | public SimpleCompletionPolicy(int chunkSize) { |
| 45 | super(); |
| 46 | this.chunkSize = chunkSize; |
| 47 | } |
| 48 | |
| 49 | public void setChunkSize(int chunkSize) { |
| 50 | this.chunkSize = chunkSize; |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * Reset the counter. |
| 55 | * |
| 56 | * @see org.springframework.batch.repeat.CompletionPolicy#start(RepeatContext) |
| 57 | */ |
| 58 | public RepeatContext start(RepeatContext context) { |
| 59 | return new SimpleTerminationContext(context); |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Terminate if the chunk size has been reached, or the result is null. |
| 64 | * |
| 65 | * @see org.springframework.batch.repeat.CompletionPolicy#isComplete(RepeatContext, |
| 66 | * ExitStatus) |
| 67 | * @throws RuntimeException (normally terminating the batch) if the result is |
| 68 | * itself an exception. |
| 69 | */ |
| 70 | public boolean isComplete(RepeatContext context, ExitStatus result) { |
| 71 | return super.isComplete(context, result) || ((SimpleTerminationContext) context).isComplete(); |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Terminate if the chunk size has been reached. |
| 76 | * |
| 77 | * @see org.springframework.batch.repeat.CompletionPolicy#isComplete(RepeatContext) |
| 78 | */ |
| 79 | public boolean isComplete(RepeatContext context) { |
| 80 | return ((SimpleTerminationContext) context).isComplete(); |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Increment the counter in the context. |
| 85 | * |
| 86 | * @see org.springframework.batch.repeat.CompletionPolicy#update(RepeatContext) |
| 87 | */ |
| 88 | public void update(RepeatContext context) { |
| 89 | ((SimpleTerminationContext) context).update(); |
| 90 | } |
| 91 | |
| 92 | protected class SimpleTerminationContext extends RepeatContextSupport { |
| 93 | |
| 94 | public SimpleTerminationContext(RepeatContext context) { |
| 95 | super(context); |
| 96 | } |
| 97 | |
| 98 | public void update() { |
| 99 | increment(); |
| 100 | } |
| 101 | |
| 102 | public boolean isComplete() { |
| 103 | return getStartedCount() >= chunkSize; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | } |