01: /*
02: * (c) Copyright 2008 by Volker Bergmann. All rights reserved.
03: *
04: * Redistribution and use in source and binary forms, with or without
05: * modification, is permitted under the terms of the
06: * GNU General Public License.
07: *
08: * For redistributing this software or a derivative work under a license other
09: * than the GPL-compatible Free Software License as defined by the Free
10: * Software Foundation or approved by OSI, you must first obtain a commercial
11: * license to this software product from Volker Bergmann.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
14: * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
15: * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
16: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
17: * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
18: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24: * POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: package org.databene.platform.db;
28:
29: import java.sql.Connection;
30: import java.sql.PreparedStatement;
31: import java.sql.SQLException;
32:
33: import org.databene.commons.ConfigurationError;
34: import org.databene.id.IdProvider;
35:
36: /**
37: * Iterates the results of a SQL query.<br/><br/>
38: * Created: 27.01.2008 18:40:36
39: * @since 0.4.0
40: * @author Volker Bergmann
41: */
42: public class QueryIdProvider implements IdProvider<String> {
43:
44: private PreparedStatement statement;
45:
46: private String query;
47:
48: // constructors ----------------------------------------------------------------------------------------------------
49:
50: public QueryIdProvider(Connection connection, String query) {
51: try {
52: this .query = query;
53: this .statement = connection.prepareStatement(query);
54: } catch (SQLException e) {
55: throw new ConfigurationError("Statement creation failed: "
56: + query, e);
57: }
58: }
59:
60: // HeavyweightIterator interface -----------------------------------------------------------------------------------
61:
62: public Class<String> getType() {
63: return String.class;
64: }
65:
66: public boolean hasNext() {
67: return (statement != null);
68: }
69:
70: public String next() {
71: return DBUtil.queryWithOneCellResult(statement);
72: }
73:
74: public void remove() {
75: throw new UnsupportedOperationException(
76: "Removal is not supported.");
77: }
78:
79: public void close() {
80: DBUtil.close(statement);
81: this .statement = null;
82: }
83:
84: // java.lang.Object overrides --------------------------------------------------------------------------------------
85:
86: @Override
87: public String toString() {
88: return getClass().getSimpleName() + '[' + query + ']';
89: }
90:
91: }
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