Example usage for com.google.gson.internal.bind JsonTreeReader JsonTreeReader

Introduction

In this page you can find the example usage for com.google.gson.internal.bind JsonTreeReader JsonTreeReader.

Prototype

public JsonTreeReader(JsonElement element) 

Source Link

Usage

From source file:edu.mit.media.funf.config.DefaultRuntimeTypeAdapterFactory.java

License:Open Source License

@Override
public <T> TypeAdapter<T> create(final Gson gson, final TypeToken<T> type) {
    if (baseClass.isAssignableFrom(type.getRawType())) {
        return new TypeAdapter<T>() {
            @Override// w  w w .  j  a  va2s.co  m
            public void write(JsonWriter out, T value) throws IOException {
                if (value == null) {
                    out.nullValue();
                    return;
                }
                // TODO: cache these only once per runtime type
                final TypeAdapter delegate = delegateFactory.create(gson, TypeToken.get(value.getClass()));
                JsonTreeWriter treeWriter = new JsonTreeWriter();
                delegate.write(treeWriter, value);
                JsonElement el = treeWriter.get();

                if (el.isJsonObject()) {
                    JsonObject elObject = el.getAsJsonObject();
                    elObject.addProperty(RuntimeTypeAdapterFactory.TYPE, value.getClass().getName());
                    Streams.write(elObject, out);
                } else {
                    Streams.write(el, out);
                }
            }

            @Override
            public T read(JsonReader in) throws IOException {
                // TODO: need to handle null
                JsonElement el = Streams.parse(in);
                Class<? extends T> runtimeType = getRuntimeType(el, type);
                if (runtimeType == null) {
                    throw new ParseException("RuntimeTypeAdapter: Unable to parse runtime type.");
                }
                // TODO: cache these only once per runtime type
                final TypeAdapter<? extends T> delegate = delegateFactory.create(gson,
                        TypeToken.get(runtimeType));

                if (el.isJsonPrimitive() && el.getAsJsonPrimitive().isString()) {
                    JsonObject typeObject = new JsonObject();
                    typeObject.addProperty(TYPE, el.getAsString());
                    el = typeObject;
                }

                return delegate.read(new JsonTreeReader(el));
            }

        };
    }
    return null;
}

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