@Override
public void write(JsonWriter out, Patch<Data> value) throws IOException {
JsonTreeWriter treeWriter = new JsonTreeWriter();
treeWriter.setSerializeNulls(true);
_dataAdapter.write(treeWriter, value.data());
JsonObject tree = treeWriter.get().getAsJsonObject();
Set<String> presentJsonProperties = new HashSet<>();
for (Field field : value.changedFields()) {
SerializedName nameSpecifier = field.getAnnotation(SerializedName.class);
String jsonPropertyName = (nameSpecifier != null ? nameSpecifier.value() : field.getName());
presentJsonProperties.add(jsonPropertyName);
}
for (Map.Entry<String, JsonElement> entry : new ArrayList<>(tree.entrySet())) {
if (!presentJsonProperties.contains(entry.getKey())) {
tree.remove(entry.getKey());
}
}
// If a data field changed to null the null should be serialized.
// This is the whole point of this adapter.
ObjectTargetedJsonWriter patchWriter = new ObjectTargetedJsonWriter(out);
patchWriter.setTargetedSerializeNulls(true);
_gson.getAdapter(JsonObject.class).write(patchWriter, tree);
}
/**
* Converts {@code value} to a JSON tree.
*
* @param value the Java object to convert. May be null.
* @return the converted JSON tree. May be {@link JsonNull}.
* @since 2.2
*/
public final JsonElement toJsonTree(T value) {
try {
JsonTreeWriter jsonWriter = new JsonTreeWriter();
write(jsonWriter, value);
return jsonWriter.get();
} catch (IOException e) {
throw new JsonIOException(e);
}
}
public JsonElement toJsonTree(Object paramObject, Type paramType) {
JsonTreeWriter localJsonTreeWriter = new JsonTreeWriter();
toJson(paramObject, paramType, localJsonTreeWriter);
return localJsonTreeWriter.get();
}