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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.step.tasklet;
17  
18  import org.springframework.batch.core.StepContribution;
19  import org.springframework.batch.core.scope.context.ChunkContext;
20  import org.springframework.batch.repeat.RepeatStatus;
21  
22  /**
23   * Strategy for processing in a step.
24   * 
25   * @author Dave Syer
26   * 
27   */
28  public interface Tasklet {
29  
30  	/**
31  	 * Given the current context in the form of a step contribution, do whatever
32  	 * is necessary to process this unit inside a transaction. Implementations
33  	 * return {@link RepeatStatus#FINISHED} if finished. If not they return
34  	 * {@link RepeatStatus#CONTINUABLE}. On failure throws an exception.
35  	 * 
36  	 * @param contribution mutable state to be passed back to update the current
37  	 * step execution
38  	 * @param chunkContext attributes shared between invocations but not between
39  	 * restarts
40  	 * @return an {@link RepeatStatus} indicating whether processing is
41  	 * continuable.
42  	 */
43  	RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception;
44  
45  }