-
Notifications
You must be signed in to change notification settings - Fork 103
Expand file tree
/
Copy pathWrapper.java
More file actions
81 lines (75 loc) · 3.19 KB
/
Wrapper.java
File metadata and controls
81 lines (75 loc) · 3.19 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
/*
* Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*/
package java.sql;
/**
* Interface for JDBC classes which provide the ability to retrieve the delegate instance when the instance
* in question is in fact a proxy class.
* <p>
* The wrapper pattern is employed by many JDBC driver implementations to provide extensions beyond
* the traditional JDBC API that are specific to a data source. Developers may wish to gain access to
* these resources that are wrapped (the delegates) as proxy class instances representing the
* the actual resources. This interface describes a standard mechanism to access
* these wrapped resources
* represented by their proxy, to permit direct access to the resource delegates.
*
* @since 1.6
*/
public interface Wrapper {
/**
* Returns an object that implements the given interface to allow access to
* non-standard methods, or standard methods not exposed by the proxy.
*
* If the receiver implements the interface then the result is the receiver
* or a proxy for the receiver. If the receiver is a wrapper
* and the wrapped object implements the interface then the result is the
* wrapped object or a proxy for the wrapped object. Otherwise return the
* the result of calling <code>unwrap</code> recursively on the wrapped object
* or a proxy for that result. If the receiver is not a
* wrapper and does not implement the interface, then an <code>SQLException</code> is thrown.
*
* @param <T> the type of the class modeled by this Class object
* @param iface A Class defining an interface that the result must implement.
* @return an object that implements the interface. May be a proxy for the actual implementing object.
* @throws java.sql.SQLException If no object found that implements the interface
* @since 1.6
*/
<T> T unwrap(java.lang.Class<T> iface) throws java.sql.SQLException;
/**
* Returns true if this either implements the interface argument or is directly or indirectly a wrapper
* for an object that does. Returns false otherwise. If this implements the interface then return true,
* else if this is a wrapper then return the result of recursively calling <code>isWrapperFor</code> on the wrapped
* object. If this does not implement the interface and is not a wrapper, return false.
* This method should be implemented as a low-cost operation compared to <code>unwrap</code> so that
* callers can use this method to avoid expensive <code>unwrap</code> calls that may fail. If this method
* returns true then calling <code>unwrap</code> with the same argument should succeed.
*
* @param iface a Class defining an interface.
* @return true if this implements the interface or directly or indirectly wraps an object that does.
* @throws java.sql.SQLException if an error occurs while determining whether this is a wrapper
* for an object with the given interface.
* @since 1.6
*/
boolean isWrapperFor(java.lang.Class<?> iface) throws java.sql.SQLException;
}