1 /*
2 * Copyright 2006-2013 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.core.resource;
18
19 import org.springframework.batch.core.JobParameters;
20 import org.springframework.batch.core.StepExecution;
21 import org.springframework.batch.core.StepExecutionListener;
22 import org.springframework.batch.core.listener.StepExecutionListenerSupport;
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.policy.SimpleCompletionPolicy;
27 import org.springframework.util.Assert;
28
29 /**
30 * <p>
31 * A {@link CompletionPolicy} that picks up a commit interval from
32 * {@link JobParameters} by listening to the start of a step. Use anywhere that
33 * a {@link CompletionPolicy} can be used (usually at the chunk level in a
34 * step), and inject as a {@link StepExecutionListener} into the surrounding
35 * step. N.B. only after the step has started will the completion policy be
36 * usable.
37 * </p>
38 *
39 * <p>
40 * It is easier and probably preferable to simply declare the chunk with a
41 * commit-interval that is a late-binding expression (e.g.
42 * <code>#{jobParameters['commit.interval']}</code>). That feature is available
43 * from of Spring Batch 2.1.7.
44 * </p>
45 *
46 * @author Dave Syer
47 *
48 * @see CompletionPolicy
49 */
50 public class StepExecutionSimpleCompletionPolicy extends StepExecutionListenerSupport implements CompletionPolicy {
51
52 private CompletionPolicy delegate;
53
54 private String keyName = "commit.interval";
55
56 /**
57 * Public setter for the key name of a Long value in the
58 * {@link JobParameters} that will contain a commit interval. Defaults to
59 * "commit.interval".
60 * @param keyName the keyName to set
61 */
62 public void setKeyName(String keyName) {
63 this.keyName = keyName;
64 }
65
66 /**
67 * Set up a {@link SimpleCompletionPolicy} with a commit interval taken from
68 * the {@link JobParameters}. If there is a Long parameter with the given
69 * key name, the intValue of this parameter is used. If not an exception
70 * will be thrown.
71 *
72 * @see org.springframework.batch.core.listener.StepExecutionListenerSupport#beforeStep(org.springframework.batch.core.StepExecution)
73 */
74 @Override
75 public void beforeStep(StepExecution stepExecution) {
76 JobParameters jobParameters = stepExecution.getJobParameters();
77 Assert.state(jobParameters.getParameters().containsKey(keyName),
78 "JobParameters do not contain Long parameter with key=[" + keyName + "]");
79 delegate = new SimpleCompletionPolicy((int) jobParameters.getLong(keyName));
80 }
81
82 /**
83 * @param context
84 * @param result
85 * @return true if the commit interval has been reached or the result
86 * indicates completion
87 * @see CompletionPolicy#isComplete(RepeatContext, RepeatStatus)
88 */
89 @Override
90 public boolean isComplete(RepeatContext context, RepeatStatus result) {
91 Assert.state(delegate != null, "The delegate resource has not been initialised. "
92 + "Remember to register this object as a StepListener.");
93 return delegate.isComplete(context, result);
94 }
95
96 /**
97 * @param context
98 * @return if the commit interval has been reached
99 * @see org.springframework.batch.repeat.CompletionPolicy#isComplete(org.springframework.batch.repeat.RepeatContext)
100 */
101 @Override
102 public boolean isComplete(RepeatContext context) {
103 Assert.state(delegate != null, "The delegate resource has not been initialised. "
104 + "Remember to register this object as a StepListener.");
105 return delegate.isComplete(context);
106 }
107
108 /**
109 * @param parent
110 * @return a new {@link RepeatContext}
111 * @see org.springframework.batch.repeat.CompletionPolicy#start(org.springframework.batch.repeat.RepeatContext)
112 */
113 @Override
114 public RepeatContext start(RepeatContext parent) {
115 Assert.state(delegate != null, "The delegate resource has not been initialised. "
116 + "Remember to register this object as a StepListener.");
117 return delegate.start(parent);
118 }
119
120 /**
121 * @param context
122 * @see org.springframework.batch.repeat.CompletionPolicy#update(org.springframework.batch.repeat.RepeatContext)
123 */
124 @Override
125 public void update(RepeatContext context) {
126 Assert.state(delegate != null, "The delegate resource has not been initialised. "
127 + "Remember to register this object as a StepListener.");
128 delegate.update(context);
129 }
130
131 /**
132 * Delegates to the wrapped {@link CompletionPolicy} if set, otherwise
133 * returns the value of {@link #setKeyName(String)}.
134 */
135 @Override
136 public String toString() {
137 return (delegate == null) ? keyName : delegate.toString();
138 }
139
140 }