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comparison src/main/java/nl/cwi/monetdb/jdbc/MonetWrapper.java @ 0:a5a898f6886c

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Copy of MonetDB java directory changeset e6e32756ad31.
author Sjoerd Mullender <sjoerd@acm.org>
date Wed, 21 Sep 2016 09:34:48 +0200 (2016-09-21)
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1 /*
2 * This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
5 *
6 * Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
7 */
8
9 package nl.cwi.monetdb.jdbc;
10
11 import java.sql.*;
12
13 /**
14 * A Wrapper class that implements nothing.
15 *
16 * This Class is used to simply provide JDBC4 Wrapper functions, for as
17 * long as we don't really understand that they are for and what they
18 * are supposed to do. Hence the implementations are very stupid and
19 * non-useful, ignoring any argument and claiming stuff doesn't work, or
20 * won't work out.
21 *
22 * @author Fabian Groffen
23 * @version 1.0
24 */
25 public class MonetWrapper implements Wrapper {
26 /**
27 * Returns true if this either implements the interface argument or
28 * is directly or indirectly a wrapper for an object that does.
29 * Returns false otherwise. If this implements the interface then
30 * return true, else if this is a wrapper then return the result of
31 * recursively calling isWrapperFor on the wrapped object. If this
32 * does not implement the interface and is not a wrapper, return
33 * false. This method should be implemented as a low-cost operation
34 * compared to unwrap so that callers can use this method to avoid
35 * expensive unwrap calls that may fail. If this method returns true
36 * then calling unwrap with the same argument should succeed.
37 *
38 * @param iface a Class defining an interface.
39 * @return true if this implements the interface or directly or
40 * indirectly wraps an object that does.
41 * @throws SQLException if an error occurs while determining
42 * whether this is a wrapper for an object with the given
43 * interface.
44 */
45 @Override
46 public boolean isWrapperFor(Class<?> iface) throws SQLException {
47 return false;
48 }
49
50 /**
51 * Returns an object that implements the given interface to allow
52 * access to non-standard methods, or standard methods not exposed
53 * by the proxy. If the receiver implements the interface then the
54 * result is the receiver or a proxy for the receiver. If the
55 * receiver is a wrapper and the wrapped object implements the
56 * interface then the result is the wrapped object or a proxy for
57 * the wrapped object. Otherwise return the the result of calling
58 * unwrap recursively on the wrapped object or a proxy for that
59 * result. If the receiver is not a wrapper and does not implement
60 * the interface, then an SQLException is thrown.
61 *
62 * @param iface A Class defining an interface that the result must
63 * implement.
64 * @return an object that implements the interface. May be a proxy
65 * for the actual implementing object.
66 * @throws SQLException If no object found that implements the
67 * interface
68 */
69 @Override
70 public <T> T unwrap(Class<T> iface) throws SQLException {
71 throw new SQLException("No object found (not implemented)", "0A000");
72 }
73 }