| 1 | /* |
| 2 | * Copyright (C) 2011 Google Inc. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.google.gson.internal.bind; |
| 18 | |
| 19 | import com.google.gson.Gson; |
| 20 | import com.google.gson.TypeAdapter; |
| 21 | import com.google.gson.TypeAdapterFactory; |
| 22 | import com.google.gson.internal.LinkedTreeMap; |
| 23 | import com.google.gson.reflect.TypeToken; |
| 24 | import com.google.gson.stream.JsonReader; |
| 25 | import com.google.gson.stream.JsonToken; |
| 26 | import com.google.gson.stream.JsonWriter; |
| 27 | |
| 28 | import java.io.IOException; |
| 29 | import java.util.ArrayList; |
| 30 | import java.util.List; |
| 31 | import java.util.Map; |
| 32 | |
| 33 | /** |
| 34 | * Adapts types whose static type is only 'Object'. Uses getClass() on |
| 35 | * serialization and a primitive/Map/List on deserialization. |
| 36 | */ |
| 37 | public final class ObjectTypeAdapter extends TypeAdapter<Object> { |
| 38 | public static final TypeAdapterFactory FACTORY = new TypeAdapterFactory() { |
| 39 | @SuppressWarnings("unchecked") |
| 40 | public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) { |
| 41 | if (type.getRawType() == Object.class) { |
| 42 | return (TypeAdapter<T>) new ObjectTypeAdapter(gson); |
| 43 | } |
| 44 | return null; |
| 45 | } |
| 46 | }; |
| 47 | |
| 48 | private final Gson gson; |
| 49 | |
| 50 | private ObjectTypeAdapter(Gson gson) { |
| 51 | this.gson = gson; |
| 52 | } |
| 53 | |
| 54 | @Override public Object read(JsonReader in) throws IOException { |
| 55 | JsonToken token = in.peek(); |
| 56 | switch (token) { |
| 57 | case BEGIN_ARRAY: |
| 58 | List<Object> list = new ArrayList<Object>(); |
| 59 | in.beginArray(); |
| 60 | while (in.hasNext()) { |
| 61 | list.add(read(in)); |
| 62 | } |
| 63 | in.endArray(); |
| 64 | return list; |
| 65 | |
| 66 | case BEGIN_OBJECT: |
| 67 | Map<String, Object> map = new LinkedTreeMap<String, Object>(); |
| 68 | in.beginObject(); |
| 69 | while (in.hasNext()) { |
| 70 | map.put(in.nextName(), read(in)); |
| 71 | } |
| 72 | in.endObject(); |
| 73 | return map; |
| 74 | |
| 75 | case STRING: |
| 76 | return in.nextString(); |
| 77 | |
| 78 | case NUMBER: |
| 79 | return in.nextDouble(); |
| 80 | |
| 81 | case BOOLEAN: |
| 82 | return in.nextBoolean(); |
| 83 | |
| 84 | case NULL: |
| 85 | in.nextNull(); |
| 86 | return null; |
| 87 | |
| 88 | default: |
| 89 | throw new IllegalStateException(); |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | @SuppressWarnings("unchecked") |
| 94 | @Override public void write(JsonWriter out, Object value) throws IOException { |
| 95 | if (value == null) { |
| 96 | out.nullValue(); |
| 97 | return; |
| 98 | } |
| 99 | |
| 100 | TypeAdapter<Object> typeAdapter = (TypeAdapter<Object>) gson.getAdapter(value.getClass()); |
| 101 | if (typeAdapter instanceof ObjectTypeAdapter) { |
| 102 | out.beginObject(); |
| 103 | out.endObject(); |
| 104 | return; |
| 105 | } |
| 106 | |
| 107 | typeAdapter.write(out, value); |
| 108 | } |
| 109 | } |