javax.batch.api.chunk.AbstractItemReader Maven / Gradle / Ivy
/*
* Copyright 2012 International Business Machines Corp.
*
* See the NOTICE file distributed with this work for additional information
* regarding copyright ownership. 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 javax.batch.api.chunk;
import java.io.Serializable;
/**
* The AbstractItemReader provides default implementations
* of less commonly implemented methods.
*
*/
public abstract class AbstractItemReader implements ItemReader {
/**
* Override this method if the ItemReader requires
* any open time processing.
* The default implementation does nothing.
*
* @param checkpoint last checkpoint for this ItemReader - may be null.
* @throws Exception (or subclass) if an error occurs.
*/
@Override
public void open(Serializable checkpoint) throws Exception { }
/**
* Override this method if the ItemReader requires
* any close time processing.
* The default implementation does nothing.
*
* @throws Exception (or subclass) if an error occurs.
*/
@Override
public void close() throws Exception { }
/**
* Implement read logic for the ItemReader in this
* method.
*
* @return next item or null
* @throws Exception (or subclass) if an error occurs.
*/
@Override
public abstract Object readItem() throws Exception;
/**
* Override this method if the ItemReader supports
* checkpoints.
* The default implementation returns null.
*
* @return checkpoint data
* @throws Exception (or subclass) if an error occurs.
*/
@Override
public Serializable checkpointInfo() throws Exception {
return null;
}
}