/*
* Copyright 2006-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.batch.repeat;
/**
* Interface for listeners to the batch process. Implementers can provide
* enhance the behaviour of a batch in small cross-cutting modules. The
* framework provides callbacks at key points in the processing.
*
* @author Dave Syer
*
*/
public interface RepeatListener {
/**
* Called by the framework before each batch item. Implementers can halt a
* batch by setting the complete flag on the context.
*
* @param context the current batch context.
*/
void before(RepeatContext context);
/**
* Called by the framework after each item has been processed, unless the
* item processing results in an exception. This method is called as soon as
* the result is known.
*
* @param context the current batch context
* @param result the result of the callback
*/
void after(RepeatContext context, RepeatStatus result);
/**
* Called once at the start of a complete batch, before any items are
* processed. Implementers can use this method to acquire any resources that
* might be needed during processing. Implementers can halt the current
* operation by setting the complete flag on the context. To halt all
* enclosing batches (the whole job), the would need to use the parent
* context (recursively).
*
* @param context the current batch context
*/
void open(RepeatContext context);
/**
* Called when a repeat callback fails by throwing an exception. There will
* be one call to this method for each exception thrown during a repeat
* operation (e.g. a chunk).<br/>
*
* There is no need to re-throw the exception here - that will be done by
* the enclosing framework.
*
* @param context the current batch context
* @param e the error that was encountered in an item callback.
*/
void onError(RepeatContext context, Throwable e);
/**
* Called once at the end of a complete batch, after normal or abnormal
* completion (i.e. even after an exception). Implementers can use this
* method to clean up any resources.
*
* @param context the current batch context.
*/
void close(RepeatContext context);
}
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