JsonReader.java

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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 io.material.demo.codelab.buildingbeautifulapps;

import android.util.Log;

import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.Type;

/**
 * Utilities for reading JSON input into Java objects.
 */
public class JsonReader {
    private static final String TAG = JsonReader.class.getSimpleName();

    public static <T> T readJsonStream(InputStream inputStream, Type typeOfT) throws IOException {
        Writer writer = new StringWriter();
        char[] buffer = new char[1024];
        try {
            Reader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
            int pointer;
            while ((pointer = reader.read(buffer)) != -1) {
                writer.write(buffer, 0, pointer);
            }
        } finally {
            try {
                inputStream.close();
            } catch (IOException exception) {
                Log.e(TAG, "Error closing the input stream.", exception);
            }
        }
        String jsonString = writer.toString();
        Gson gson = new Gson();
        return gson.fromJson(jsonString, typeOfT);
    }
}