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1   /*
2    * Copyright 2002-2006 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  
17  package org.gageot.excel.core;
18  
19  import java.io.IOException;
20  
21  import org.apache.poi.hssf.usermodel.HSSFRow;
22  
23  /***
24   * Callback interface used by ExcelTemplate's query methods.
25   * Implementations of this interface perform the actual work of extracting
26   * results from rows, but don't need to worry about exception handling.
27   * IOExceptions will be caught and handled correctly by the ExcelTemplate class.
28   *
29   * <p>In contrast to a SheetExtractor, a RowCallbackHandler object is
30   * typically stateful: It keeps the result state within the object, to be
31   * available for later inspection.
32   *
33   * @author David Gageot
34   * @see SheetExtractor
35   * @see RowMapper
36   */
37  public interface RowCallbackHandler {
38  
39  	/***
40  	 * Implementations must implement this method to process each row of data
41  	 * in the HSSFSheet. This method should extract the current values.
42  	 * Exactly what the implementation chooses to do is up to it;
43  	 * a trivial implementation might simply count rows,
44  	 * while another implementation might build an XML document.
45  	 * @param row the HSSFRow to process
46  	 * @param rowNum the number of the current row
47  	 * @throws IOException if a IOException is encountered getting
48  	 * column values (that is, there's no need to catch IOException)
49  	 */
50  	void processRow (HSSFRow row, int rowNum) throws IOException;
51  }