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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
// Protocol Buffers - Google's data interchange format
// Copyright 2013 Google Inc. All rights reserved.
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package com.google.protobuf.nano;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
/**
* Represents an extension.
*
* @author bduff@google.com (Brian Duff)
* @param <T> the type of the extension.
*/
public class Extension<T> {
public final int fieldNumber;
public boolean isRepeatedField;
public Class<T> fieldType;
public Class<T> listType;
private Extension(int fieldNumber, TypeLiteral<T> type) {
this.fieldNumber = fieldNumber;
isRepeatedField = type.isList();
fieldType = type.getTargetClass();
listType = isRepeatedField ? type.getListType() : null;
}
/**
* Creates a new instance of {@code Extension} for the specified {@code fieldNumber} and
* {@code type}.
*/
public static <T> Extension<T> create(int fieldNumber, TypeLiteral<T> type) {
return new Extension<T>(fieldNumber, type);
}
/**
* Creates a new instance of {@code Extension} for the specified {@code fieldNumber} and
* {@code type}. This version is used for repeated fields.
*/
public static <T> Extension<List<T>> createRepeated(int fieldNumber, TypeLiteral<List<T>> type) {
return new Extension<List<T>>(fieldNumber, type);
}
/**
* Represents a generic type literal. We can't typesafely reference a
* Class<List<Foo>>.class in Java, so we use this instead.
* See: http://gafter.blogspot.com/2006/12/super-type-tokens.html
*
* <p>Somewhat specialized because we only ever have a Foo or a List<Foo>.
*/
public static abstract class TypeLiteral<T> {
private final Type type;
protected TypeLiteral() {
Type superclass = getClass().getGenericSuperclass();
if (superclass instanceof Class) {
throw new RuntimeException("Missing type parameter");
}
this.type = ((ParameterizedType) superclass).getActualTypeArguments()[0];
}
/**
* If the generic type is a list, returns {@code true}.
*/
private boolean isList() {
return type instanceof ParameterizedType;
}
@SuppressWarnings("unchecked")
private Class<T> getListType() {
return (Class<T>) ((ParameterizedType) type).getRawType();
}
/**
* If the generic type is a list, returns the type of element in the list. Otherwise,
* returns the actual type.
*/
@SuppressWarnings("unchecked")
private Class<T> getTargetClass() {
if (isList()) {
return (Class<T>) ((ParameterizedType) type).getActualTypeArguments()[0];
}
return (Class<T>) type;
}
}
}
|
