TypeAdapter.java

/*
 * 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.smartandroid.sa.json.internal.bind;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;

import com.smartandroid.sa.json.JsonElement;
import com.smartandroid.sa.json.internal.Streams;
import com.smartandroid.sa.json.reflect.TypeToken;
import com.smartandroid.sa.json.stream.JsonReader;
import com.smartandroid.sa.json.stream.JsonWriter;

public abstract class TypeAdapter<T> {
	public abstract T read(JsonReader reader) throws IOException;

	public abstract void write(JsonWriter writer, T value) throws IOException;

	public final String toJson(T value) throws IOException {
		StringWriter stringWriter = new StringWriter();
		write(stringWriter, value);
		return stringWriter.toString();
	}

	public final void write(Writer out, T value) throws IOException {
		JsonWriter writer = new JsonWriter(out);
		write(writer, value);
	}

	public final T fromJson(String json) throws IOException {
		return read(new StringReader(json));
	}

	public final T read(Reader in) throws IOException {
		JsonReader reader = new JsonReader(in);
		reader.setLenient(true);
		return read(reader);
	}

	public JsonElement toJsonElement(T src) {
		try {
			StringWriter stringWriter = new StringWriter();
			JsonWriter jsonWriter = new JsonWriter(stringWriter);
			jsonWriter.setLenient(true);
			write(jsonWriter, src);
			JsonReader reader = new JsonReader(new StringReader(
					stringWriter.toString()));
			reader.setLenient(true);
			return Streams.parse(reader);
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	public T fromJsonElement(JsonElement json) {
		try {
			StringWriter stringWriter = new StringWriter();
			JsonWriter jsonWriter = new JsonWriter(stringWriter);
			jsonWriter.setLenient(true);
			Streams.write(json, false, jsonWriter);
			JsonReader jsonReader = new JsonReader(new StringReader(
					stringWriter.toString()));
			jsonReader.setLenient(true);
			return read(jsonReader);
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}

	public interface Factory {
		<T> TypeAdapter<T> create(MiniGson context, TypeToken<T> type);
	}
}