1. 

  2. /*

  3.  * Copyright 2002-2004 the original author or authors.

  4.  * 

  5.  * Licensed under the Apache License, Version 2.0 (the "License");

  6.  * you may not use this file except in compliance with the License.

  7.  * You may obtain a copy of the License at

  8.  * 

  9.  *      http://www.apache.org/licenses/LICENSE-2.0

  10.  * 

  11.  * Unless required by applicable law or agreed to in writing, software

  12.  * distributed under the License is distributed on an "AS IS" BASIS,

  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  14.  * See the License for the specific language governing permissions and

  15.  * limitations under the License.

  16.  */ 

  17. 

  18. package org.springframework.jdbc.core;

  19. 

  20. import java.sql.ResultSet;

  21. import java.sql.SQLException;

  22. 

  23. import org.springframework.dao.DataAccessException;

  24. 

  25. /** 

  26.  * Callback interface used by JdbcTemplate's query methods.

  27.  * Implementations of this interface perform the actual work of extracting

  28.  * results, but don't need to worry about exception handling. SQLExceptions

  29.  * will be caught and handled correctly by the JdbcTemplate class.

  30.  *

  31.  * <p>This interface is mainly used within the JDBC framework.

  32.  * A RowCallbackHandler is usually a simpler choice for ResultSet processing,

  33.  * in particular a RowMapperResultReader in combination with a RowMapper.

  34.  *

  35.  * <p>Note: In contrast to a RowCallbackHandler, a ResultSetExtractor object

  36.  * is typically stateless and thus reusable, as long as it doesn't access

  37.  * stateful resources (like output streams when streaming LOB contents)

  38.  * or keep result state within the object.

  39.  *

  40.  * @author Rod Johnson

  41.  * @since April 24, 2003

  42.  * @version $Id: ResultSetExtractor.java,v 1.6 2004/05/27 14:46:26 jhoeller Exp $

  43.  * @see JdbcTemplate

  44.  * @see RowCallbackHandler

  45.  * @see RowMapperResultReader

  46.  * @see org.springframework.jdbc.core.support.AbstractLobStreamingResultSetExtractor

  47.  */

  48. public interface ResultSetExtractor {

  49. 	

  50. 	/** 

  51. 	 * Implementations must implement this method to process

  52. 	 * all rows in the ResultSet.

  53. 	 * @param rs ResultSet to extract data from. Implementations should

  54. 	 * not close this: it will be closed by the JdbcTemplate.

  55. 	 * @return an arbitrary result object, or null if none

  56. 	 * (the extractor will typically be stateful in the latter case).

  57. 	 * @throws SQLException if a SQLException is encountered getting column

  58. 	 * values or navigating (that is, there's no need to catch SQLException)

  59. 	 * @throws DataAccessException in case of custom exceptions

  60. 	 */

  61. 	Object extractData(ResultSet rs) throws SQLException, DataAccessException;

  62. 

  63. }