| 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 java.util.ArrayList; |
| 20 | import java.util.Arrays; |
| 21 | import java.util.List; |
| 22 | |
| 23 | import org.springframework.batch.repeat.CompletionPolicy; |
| 24 | import org.springframework.batch.repeat.RepeatContext; |
| 25 | import org.springframework.batch.repeat.RepeatStatus; |
| 26 | import org.springframework.batch.repeat.context.RepeatContextSupport; |
| 27 | |
| 28 | /** |
| 29 | * Composite policy that loops through a list of delegate policies and answers |
| 30 | * calls by a concensus. |
| 31 | * |
| 32 | * @author Dave Syer |
| 33 | * |
| 34 | */ |
| 35 | public class CompositeCompletionPolicy implements CompletionPolicy { |
| 36 | |
| 37 | CompletionPolicy[] policies = new CompletionPolicy[0]; |
| 38 | |
| 39 | /** |
| 40 | * Setter for the policies. |
| 41 | * |
| 42 | * @param policies |
| 43 | */ |
| 44 | public void setPolicies(CompletionPolicy[] policies) { |
| 45 | this.policies = Arrays.asList(policies).toArray(new CompletionPolicy[policies.length]); |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * This policy is complete if any of the composed policies is complete. |
| 50 | * |
| 51 | * @see org.springframework.batch.repeat.CompletionPolicy#isComplete(org.springframework.batch.repeat.RepeatContext, |
| 52 | * RepeatStatus) |
| 53 | */ |
| 54 | @Override |
| 55 | public boolean isComplete(RepeatContext context, RepeatStatus result) { |
| 56 | RepeatContext[] contexts = ((CompositeBatchContext) context).contexts; |
| 57 | CompletionPolicy[] policies = ((CompositeBatchContext) context).policies; |
| 58 | for (int i = 0; i < policies.length; i++) { |
| 59 | if (policies[i].isComplete(contexts[i], result)) { |
| 60 | return true; |
| 61 | } |
| 62 | } |
| 63 | return false; |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * This policy is complete if any of the composed policies is complete. |
| 68 | * |
| 69 | * @see org.springframework.batch.repeat.CompletionPolicy#isComplete(org.springframework.batch.repeat.RepeatContext) |
| 70 | */ |
| 71 | @Override |
| 72 | public boolean isComplete(RepeatContext context) { |
| 73 | RepeatContext[] contexts = ((CompositeBatchContext) context).contexts; |
| 74 | CompletionPolicy[] policies = ((CompositeBatchContext) context).policies; |
| 75 | for (int i = 0; i < policies.length; i++) { |
| 76 | if (policies[i].isComplete(contexts[i])) { |
| 77 | return true; |
| 78 | } |
| 79 | } |
| 80 | return false; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Create a new composite context from all the available policies. |
| 85 | * |
| 86 | * @see org.springframework.batch.repeat.CompletionPolicy#start(RepeatContext) |
| 87 | */ |
| 88 | @Override |
| 89 | public RepeatContext start(RepeatContext context) { |
| 90 | List<RepeatContext> list = new ArrayList<RepeatContext>(); |
| 91 | for (int i = 0; i < policies.length; i++) { |
| 92 | list.add(policies[i].start(context)); |
| 93 | } |
| 94 | return new CompositeBatchContext(context, list); |
| 95 | |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Update all the composed contexts, and also increment the parent context. |
| 100 | * |
| 101 | * @see org.springframework.batch.repeat.CompletionPolicy#update(org.springframework.batch.repeat.RepeatContext) |
| 102 | */ |
| 103 | @Override |
| 104 | public void update(RepeatContext context) { |
| 105 | RepeatContext[] contexts = ((CompositeBatchContext) context).contexts; |
| 106 | CompletionPolicy[] policies = ((CompositeBatchContext) context).policies; |
| 107 | for (int i = 0; i < policies.length; i++) { |
| 108 | policies[i].update(contexts[i]); |
| 109 | } |
| 110 | ((RepeatContextSupport) context).increment(); |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Composite context that knows about the policies and contexts is was |
| 115 | * created with. |
| 116 | * |
| 117 | * @author Dave Syer |
| 118 | * |
| 119 | */ |
| 120 | protected class CompositeBatchContext extends RepeatContextSupport { |
| 121 | |
| 122 | private RepeatContext[] contexts; |
| 123 | |
| 124 | // Save a reference to the policies when we were created - gives some |
| 125 | // protection against reference changes (e.g. if the number of policies |
| 126 | // change). |
| 127 | private CompletionPolicy[] policies; |
| 128 | |
| 129 | public CompositeBatchContext(RepeatContext context, List<RepeatContext> contexts) { |
| 130 | super(context); |
| 131 | this.contexts = contexts.toArray(new RepeatContext[contexts.size()]); |
| 132 | this.policies = CompositeCompletionPolicy.this.policies; |
| 133 | } |
| 134 | |
| 135 | } |
| 136 | |
| 137 | } |