+++ /dev/null
-/*
- * Copyright (C) 2011 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.google.gson.internal.bind;
-
-import com.google.gson.Gson;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonPrimitive;
-import com.google.gson.JsonSyntaxException;
-import com.google.gson.TypeAdapter;
-import com.google.gson.TypeAdapterFactory;
-import com.google.gson.internal.$Gson$Types;
-import com.google.gson.internal.ConstructorConstructor;
-import com.google.gson.internal.JsonReaderInternalAccess;
-import com.google.gson.internal.ObjectConstructor;
-import com.google.gson.internal.Streams;
-import com.google.gson.reflect.TypeToken;
-import com.google.gson.stream.JsonReader;
-import com.google.gson.stream.JsonToken;
-import com.google.gson.stream.JsonWriter;
-import java.io.IOException;
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-
-/**
- * Adapts maps to either JSON objects or JSON arrays.
- *
- * <h3>Maps as JSON objects</h3>
- * For primitive keys or when complex map key serialization is not enabled, this
- * converts Java {@link Map Maps} to JSON Objects. This requires that map keys
- * can be serialized as strings; this is insufficient for some key types. For
- * example, consider a map whose keys are points on a grid. The default JSON
- * form encodes reasonably: <pre> {@code
- * Map<Point, String> original = new LinkedHashMap<Point, String>();
- * original.put(new Point(5, 6), "a");
- * original.put(new Point(8, 8), "b");
- * System.out.println(gson.toJson(original, type));
- * }</pre>
- * The above code prints this JSON object:<pre> {@code
- * {
- * "(5,6)": "a",
- * "(8,8)": "b"
- * }
- * }</pre>
- * But GSON is unable to deserialize this value because the JSON string name is
- * just the {@link Object#toString() toString()} of the map key. Attempting to
- * convert the above JSON to an object fails with a parse exception:
- * <pre>com.google.gson.JsonParseException: Expecting object found: "(5,6)"
- * at com.google.gson.JsonObjectDeserializationVisitor.visitFieldUsingCustomHandler
- * at com.google.gson.ObjectNavigator.navigateClassFields
- * ...</pre>
- *
- * <h3>Maps as JSON arrays</h3>
- * An alternative approach taken by this type adapter when it is required and
- * complex map key serialization is enabled is to encode maps as arrays of map
- * entries. Each map entry is a two element array containing a key and a value.
- * This approach is more flexible because any type can be used as the map's key;
- * not just strings. But it's also less portable because the receiver of such
- * JSON must be aware of the map entry convention.
- *
- * <p>Register this adapter when you are creating your GSON instance.
- * <pre> {@code
- * Gson gson = new GsonBuilder()
- * .registerTypeAdapter(Map.class, new MapAsArrayTypeAdapter())
- * .create();
- * }</pre>
- * This will change the structure of the JSON emitted by the code above. Now we
- * get an array. In this case the arrays elements are map entries:
- * <pre> {@code
- * [
- * [
- * {
- * "x": 5,
- * "y": 6
- * },
- * "a",
- * ],
- * [
- * {
- * "x": 8,
- * "y": 8
- * },
- * "b"
- * ]
- * ]
- * }</pre>
- * This format will serialize and deserialize just fine as long as this adapter
- * is registered.
- */
-public final class MapTypeAdapterFactory implements TypeAdapterFactory {
- private final ConstructorConstructor constructorConstructor;
- private final boolean complexMapKeySerialization;
-
- public MapTypeAdapterFactory(ConstructorConstructor constructorConstructor,
- boolean complexMapKeySerialization) {
- this.constructorConstructor = constructorConstructor;
- this.complexMapKeySerialization = complexMapKeySerialization;
- }
-
- public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
- Type type = typeToken.getType();
-
- Class<? super T> rawType = typeToken.getRawType();
- if (!Map.class.isAssignableFrom(rawType)) {
- return null;
- }
-
- Class<?> rawTypeOfSrc = $Gson$Types.getRawType(type);
- Type[] keyAndValueTypes = $Gson$Types.getMapKeyAndValueTypes(type, rawTypeOfSrc);
- TypeAdapter<?> keyAdapter = getKeyAdapter(gson, keyAndValueTypes[0]);
- TypeAdapter<?> valueAdapter = gson.getAdapter(TypeToken.get(keyAndValueTypes[1]));
- ObjectConstructor<T> constructor = constructorConstructor.get(typeToken);
-
- @SuppressWarnings({"unchecked", "rawtypes"})
- // we don't define a type parameter for the key or value types
- TypeAdapter<T> result = new Adapter(gson, keyAndValueTypes[0], keyAdapter,
- keyAndValueTypes[1], valueAdapter, constructor);
- return result;
- }
-
- /**
- * Returns a type adapter that writes the value as a string.
- */
- private TypeAdapter<?> getKeyAdapter(Gson context, Type keyType) {
- return (keyType == boolean.class || keyType == Boolean.class)
- ? TypeAdapters.BOOLEAN_AS_STRING
- : context.getAdapter(TypeToken.get(keyType));
- }
-
- private final class Adapter<K, V> extends TypeAdapter<Map<K, V>> {
- private final TypeAdapter<K> keyTypeAdapter;
- private final TypeAdapter<V> valueTypeAdapter;
- private final ObjectConstructor<? extends Map<K, V>> constructor;
-
- public Adapter(Gson context, Type keyType, TypeAdapter<K> keyTypeAdapter,
- Type valueType, TypeAdapter<V> valueTypeAdapter,
- ObjectConstructor<? extends Map<K, V>> constructor) {
- this.keyTypeAdapter =
- new TypeAdapterRuntimeTypeWrapper<K>(context, keyTypeAdapter, keyType);
- this.valueTypeAdapter =
- new TypeAdapterRuntimeTypeWrapper<V>(context, valueTypeAdapter, valueType);
- this.constructor = constructor;
- }
-
- public Map<K, V> read(JsonReader in) throws IOException {
- JsonToken peek = in.peek();
- if (peek == JsonToken.NULL) {
- in.nextNull();
- return null;
- }
-
- Map<K, V> map = constructor.construct();
-
- if (peek == JsonToken.BEGIN_ARRAY) {
- in.beginArray();
- while (in.hasNext()) {
- in.beginArray(); // entry array
- K key = keyTypeAdapter.read(in);
- V value = valueTypeAdapter.read(in);
- V replaced = map.put(key, value);
- if (replaced != null) {
- throw new JsonSyntaxException("duplicate key: " + key);
- }
- in.endArray();
- }
- in.endArray();
- } else {
- in.beginObject();
- while (in.hasNext()) {
- JsonReaderInternalAccess.INSTANCE.promoteNameToValue(in);
- K key = keyTypeAdapter.read(in);
- V value = valueTypeAdapter.read(in);
- V replaced = map.put(key, value);
- if (replaced != null) {
- throw new JsonSyntaxException("duplicate key: " + key);
- }
- }
- in.endObject();
- }
- return map;
- }
-
- public void write(JsonWriter out, Map<K, V> map) throws IOException {
- if (map == null) {
- out.nullValue();
- return;
- }
-
- if (!complexMapKeySerialization) {
- out.beginObject();
- for (Map.Entry<K, V> entry : map.entrySet()) {
- out.name(String.valueOf(entry.getKey()));
- valueTypeAdapter.write(out, entry.getValue());
- }
- out.endObject();
- return;
- }
-
- boolean hasComplexKeys = false;
- List<JsonElement> keys = new ArrayList<JsonElement>(map.size());
-
- List<V> values = new ArrayList<V>(map.size());
- for (Map.Entry<K, V> entry : map.entrySet()) {
- JsonElement keyElement = keyTypeAdapter.toJsonTree(entry.getKey());
- keys.add(keyElement);
- values.add(entry.getValue());
- hasComplexKeys |= keyElement.isJsonArray() || keyElement.isJsonObject();
- }
-
- if (hasComplexKeys) {
- out.beginArray();
- for (int i = 0; i < keys.size(); i++) {
- out.beginArray(); // entry array
- Streams.write(keys.get(i), out);
- valueTypeAdapter.write(out, values.get(i));
- out.endArray();
- }
- out.endArray();
- } else {
- out.beginObject();
- for (int i = 0; i < keys.size(); i++) {
- JsonElement keyElement = keys.get(i);
- out.name(keyToString(keyElement));
- valueTypeAdapter.write(out, values.get(i));
- }
- out.endObject();
- }
- }
-
- private String keyToString(JsonElement keyElement) {
- if (keyElement.isJsonPrimitive()) {
- JsonPrimitive primitive = keyElement.getAsJsonPrimitive();
- if (primitive.isNumber()) {
- return String.valueOf(primitive.getAsNumber());
- } else if (primitive.isBoolean()) {
- return Boolean.toString(primitive.getAsBoolean());
- } else if (primitive.isString()) {
- return primitive.getAsString();
- } else {
- throw new AssertionError();
- }
- } else if (keyElement.isJsonNull()) {
- return "null";
- } else {
- throw new AssertionError();
- }
- }
- }
-}
projects / unical.git / blobdiff