src/com/android/retaildemo/DataReaderWriter.java

/*
 * Copyright (C) 2016 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 com.android.retaildemo;

import android.content.Context;
import android.util.Log;
import libcore.io.IoUtils;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

class DataReaderWriter {
    private static final String TAG = "DataReaderWriter";
    private static final boolean DEBUG = false;

    private static final String FILE_NAME = "last_download_info.txt";

    public static void setElapsedRealTime(Context context, long elapsedRealTime) {
        FileOutputStream fileOutputStream = null;
        DataOutputStream out = null;
        try {
            final String filePath = context.getObbDir() + File.separator + FILE_NAME;
            final File file = new File(filePath);
            if (!file.exists()) {
                file.createNewFile();
            }
            fileOutputStream = new FileOutputStream(filePath);
            out = new DataOutputStream(fileOutputStream);
            if (DEBUG) Log.d(TAG, "Writing value elapsedRealTime=" + elapsedRealTime);
            out.writeLong(elapsedRealTime);
        } catch (IOException e) {
            Log.e(TAG, "Error writing elapsedRealTime=" + elapsedRealTime + " to file", e);
        } finally {
            IoUtils.closeQuietly(out);
            IoUtils.closeQuietly(fileOutputStream);
        }
    }

    public static long getElapsedRealTime(Context context) {
        long elapsedRealTime = 0;
        final String filePath = context.getObbDir() + File.separator + FILE_NAME;
        if (!new File(filePath).exists()) {
            return elapsedRealTime;
        }
        FileInputStream fileInputStream = null;
        DataInputStream in = null;
        try {
            fileInputStream = new FileInputStream(filePath);
            in = new DataInputStream(fileInputStream);
            elapsedRealTime = in.readLong();
            if (DEBUG) Log.d(TAG, "Read value elapsedRealTime=" + elapsedRealTime);
        } catch (IOException e) {
            Log.e(TAG, "Error reading elapsedRealTime value from file", e);
        } finally {
            IoUtils.closeQuietly(in);
            IoUtils.closeQuietly(fileInputStream);
        }
        return elapsedRealTime;
    }
}