01: /*
02: * Copyright 2002-2007 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
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.springframework.jdbc.core;
18:
19: import java.sql.ResultSet;
20: import java.sql.SQLException;
21:
22: import org.springframework.dao.DataAccessException;
23:
24: /**
25: * Callback interface used by {@link JdbcTemplate}'s query methods.
26: * Implementations of this interface perform the actual work of extracting
27: * results from a {@link java.sql.ResultSet}, but don't need to worry
28: * about exception handling. {@link java.sql.SQLException SQLExceptions}
29: * will be caught and handled by the calling JdbcTemplate.
30: *
31: * <p>This interface is mainly used within the JDBC framework itself.
32: * A {@link RowMapper} is usually a simpler choice for ResultSet processing,
33: * mapping one result object per row instead of one result object for
34: * the entire ResultSet.
35: *
36: * <p>Note: In contrast to a {@link RowCallbackHandler}, a ResultSetExtractor
37: * object is typically stateless and thus reusable, as long as it doesn't
38: * access stateful resources (such as output streams when streaming LOB
39: * contents) or keep result state within the object.
40: *
41: * @author Rod Johnson
42: * @author Juergen Hoeller
43: * @since April 24, 2003
44: * @see JdbcTemplate
45: * @see RowCallbackHandler
46: * @see RowMapper
47: * @see org.springframework.jdbc.core.support.AbstractLobStreamingResultSetExtractor
48: */
49: public interface ResultSetExtractor {
50:
51: /**
52: * Implementations must implement this method to process the entire ResultSet.
53: * @param rs ResultSet to extract data from. Implementations should
54: * not close this: it will be closed by the calling JdbcTemplate.
55: * @return an arbitrary result object, or <code>null</code> 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,
62: DataAccessException;
63:
64: }
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