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1 | /*\r | |
2 | * Copyright (C) 2011 Google Inc.\r | |
3 | *\r | |
4 | * Licensed under the Apache License, Version 2.0 (the "License");\r | |
5 | * you may not use this file except in compliance with the License.\r | |
6 | * You may obtain a copy of the License at\r | |
7 | *\r | |
8 | * http://www.apache.org/licenses/LICENSE-2.0\r | |
9 | *\r | |
10 | * Unless required by applicable law or agreed to in writing, software\r | |
11 | * distributed under the License is distributed on an "AS IS" BASIS,\r | |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r | |
13 | * See the License for the specific language governing permissions and\r | |
14 | * limitations under the License.\r | |
15 | */\r | |
16 | package com.google.gson.internal.bind;\r | |
17 | \r | |
18 | import com.google.gson.Gson;\r | |
19 | import com.google.gson.TypeAdapter;\r | |
20 | import com.google.gson.reflect.TypeToken;\r | |
21 | import com.google.gson.stream.JsonReader;\r | |
22 | import com.google.gson.stream.JsonWriter;\r | |
23 | import java.io.IOException;\r | |
24 | import java.lang.reflect.Type;\r | |
25 | import java.lang.reflect.TypeVariable;\r | |
26 | \r | |
27 | final class TypeAdapterRuntimeTypeWrapper<T> extends TypeAdapter<T> {\r | |
28 | private final Gson context;\r | |
29 | private final TypeAdapter<T> delegate;\r | |
30 | private final Type type;\r | |
31 | \r | |
32 | TypeAdapterRuntimeTypeWrapper(Gson context, TypeAdapter<T> delegate, Type type) {\r | |
33 | this.context = context;\r | |
34 | this.delegate = delegate;\r | |
35 | this.type = type;\r | |
36 | }\r | |
37 | \r | |
38 | @Override\r | |
39 | public T read(JsonReader in) throws IOException {\r | |
40 | return delegate.read(in);\r | |
41 | }\r | |
42 | \r | |
43 | @SuppressWarnings({"rawtypes", "unchecked"})\r | |
44 | @Override\r | |
45 | public void write(JsonWriter out, T value) throws IOException {\r | |
46 | // Order of preference for choosing type adapters\r | |
47 | // First preference: a type adapter registered for the runtime type\r | |
48 | // Second preference: a type adapter registered for the declared type\r | |
49 | // Third preference: reflective type adapter for the runtime type (if it is a sub class of the declared type)\r | |
50 | // Fourth preference: reflective type adapter for the declared type\r | |
51 | \r | |
52 | TypeAdapter chosen = delegate;\r | |
53 | Type runtimeType = getRuntimeTypeIfMoreSpecific(type, value);\r | |
54 | if (runtimeType != type) {\r | |
55 | TypeAdapter runtimeTypeAdapter = context.getAdapter(TypeToken.get(runtimeType));\r | |
56 | if (!(runtimeTypeAdapter instanceof ReflectiveTypeAdapterFactory.Adapter)) {\r | |
57 | // The user registered a type adapter for the runtime type, so we will use that\r | |
58 | chosen = runtimeTypeAdapter;\r | |
59 | } else if (!(delegate instanceof ReflectiveTypeAdapterFactory.Adapter)) {\r | |
60 | // The user registered a type adapter for Base class, so we prefer it over the\r | |
61 | // reflective type adapter for the runtime type\r | |
62 | chosen = delegate;\r | |
63 | } else {\r | |
64 | // Use the type adapter for runtime type\r | |
65 | chosen = runtimeTypeAdapter;\r | |
66 | }\r | |
67 | }\r | |
68 | chosen.write(out, value);\r | |
69 | }\r | |
70 | \r | |
71 | /**\r | |
72 | * Finds a compatible runtime type if it is more specific\r | |
73 | */\r | |
74 | private Type getRuntimeTypeIfMoreSpecific(Type type, Object value) {\r | |
75 | if (value != null\r | |
76 | && (type == Object.class || type instanceof TypeVariable<?> || type instanceof Class<?>)) {\r | |
77 | type = value.getClass();\r | |
78 | }\r | |
79 | return type;\r | |
80 | }\r | |
81 | }\r |