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 package org.springframework.batch.core.listener;
17
18 import java.util.Arrays;
19 import java.util.Collection;
20
21 import org.springframework.batch.core.JobParameters;
22 import org.springframework.batch.core.Step;
23 import org.springframework.batch.core.StepExecution;
24 import org.springframework.batch.item.ExecutionContext;
25
26 /**
27 * This class can be used to automatically copy items from the
28 * {@link JobParameters} to the {@link Step} {@link ExecutionContext}. A list of
29 * keys should be provided that correspond to the items in the {@link Step}
30 * {@link ExecutionContext} that should be copied.
31 *
32 * @author Dave Syer
33 * @since 2.0
34 */
35 public class JobParameterExecutionContextCopyListener extends StepExecutionListenerSupport {
36
37 private Collection<String> keys = null;
38
39 /**
40 * @param keys A list of keys corresponding to items in the
41 * {@link JobParameters} that should be copied.
42 */
43 public void setKeys(String[] keys) {
44 this.keys = Arrays.asList(keys);
45 }
46
47 /**
48 * Copy attributes from the {@link JobParameters} to the {@link Step}
49 * {@link ExecutionContext}, if not already present. The the key is already
50 * present we assume that a restart is in operation and the previous value
51 * is needed. If the provided keys are empty defaults to copy all keys in
52 * the {@link JobParameters}.
53 */
54 @Override
55 public void beforeStep(StepExecution stepExecution) {
56 ExecutionContext stepContext = stepExecution.getExecutionContext();
57 JobParameters jobParameters = stepExecution.getJobParameters();
58 Collection<String> keys = this.keys;
59 if (keys == null) {
60 keys = jobParameters.getParameters().keySet();
61 }
62 for (String key : keys) {
63 if (!stepContext.containsKey(key)) {
64 stepContext.put(key, jobParameters.getParameters().get(key).getValue());
65 }
66 }
67 }
68 }