poi/src/java/org/apache/poi/hssf/eventusermodel/AbortableHSSFListener.java

/* ====================================================================
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   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
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       http://www.apache.org/licenses/LICENSE-2.0

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   distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.poi.hssf.eventusermodel;

import org.apache.poi.hssf.record.Record;

/**
 * Abstract class for use with the HSSFRequest and HSSFEventFactory, which
 *  allows for the halting of processing. 
 * Users should create subclass of this (which implements the usual
 *  HSSFListener), and then override the #abortableProcessRecord(org.apache.poi.hssf.record.Record)
 *  method to do their processing.
 * This should then be registered with the HSSFRequest (associating
 * it with Record SID's) as usual.
 *
 * @see org.apache.poi.hssf.eventusermodel.HSSFEventFactory
 * @see org.apache.poi.hssf.eventusermodel.HSSFRequest
 * @see org.apache.poi.hssf.eventusermodel.HSSFUserException
 */

public abstract class AbortableHSSFListener implements HSSFListener
{
    /**
     * This method, inherited from HSSFListener is implemented as a stub.
     * It is never called by HSSFEventFactory or HSSFRequest.
     * You should implement #abortableProcessRecord instead
     */
	@Override
    public void processRecord(org.apache.poi.hssf.record.Record record)
	{
	}

   /**
	 * Process an HSSF Record. Called when a record occurs in an HSSF file. 
	 * Provides two options for halting the processing of the HSSF file.
	 *
	 * The return value provides a means of non-error termination with a 
	 * user-defined result code. A value of zero must be returned to 
	 * continue processing, any other value will halt processing by
	 * <code>HSSFEventFactory</code> with the code being passed back by 
	 * its abortable process events methods.
	 * 
	 * Error termination can be done by throwing the HSSFUserException.
	 *
	 * Note that HSSFEventFactory will not call the inherited process 
	 *
	 * @param record the record to be processed
	 *
     * @return result code of zero for continued processing.
     *
	 * @throws HSSFUserException User code can throw this to abort 
	 * file processing by HSSFEventFactory and return diagnostic information.
     */
    public abstract short abortableProcessRecord(org.apache.poi.hssf.record.Record record) throws HSSFUserException;
}