These files enable an Android app to run a callback if and only if the device has completed its boot sequence.

BootReceiver.java

/* Copyright (C) 2016 Bypass Mobile, LLC.
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */
 
package com.bypassmobile.peripherals.deviceinfo.usb.boot;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.SystemClock;

import java.util.Iterator;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * For whatever reason ACTION_BOOT_COMPLETED is NOT a sticky broadcast... though I don't understand
 * this decision at all. Regardless, this class allows us to check whether or not the system has,
 * in fact, completed the boot sequence.
 */
public class BootReceiver extends BroadcastReceiver {

    private static boolean bootCompleted = false;

    public interface BootListener {
        void bootCompleted();
    }
    private static CopyOnWriteArrayList<BootListener> listeners = new CopyOnWriteArrayList<>();

    @Override
    public void onReceive(Context context, Intent intent) {
        if (!Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) {
            return;
        }

        bootCompleted = true;
        callAndEmptyBootListenerCallbacks();
    }

    /**
     * <p>
     *     Intelligently registers your listener by either:
     *     <ol>
     *         <li>
     *             immediately invoking your listener's callback if the system has already
     *             completed its boot, or
     *         </li>
     *         <li>
     *             setting the Application's boot receiver to fire your listener's callback
     *             once the {@link Intent#ACTION_BOOT_COMPLETED} broadcast is sent by the
     *             system.
     *         </li>
     *     </ol>
     * </p>
     * @param context The application context
     * @param listener The listener containing the callback to fire on completed boot
     */
    public static void registerBootCompleteListener(Context context, BootListener listener) {
        if (hasBootCompleted(context)) {
            listener.bootCompleted();
            return;
        }
        listeners.add(listener);
    }

    private static boolean hasBootCompleted(Context context) {
        // The bootCompleted boolean gets flipped back to false if the apk is updated.
        // Therefore, we must check whether the package was updated while the system was live
        // as well in order to know whether the boot is complete
        return bootCompleted || PackageHelper.updatedSinceSystemBoot(context) || SystemClock.elapsedRealtime() > 1000 * 60;
    }

    private static void callAndEmptyBootListenerCallbacks() {
        Iterator<BootListener> it = listeners.iterator();
        while (it.hasNext()) {
            BootListener listener = it.next();
            listeners.remove(listener);
            listener.bootCompleted();
        }
    }
}

PackageHelper.java

/* Copyright (C) 2016 Bypass Mobile, LLC.
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */

package com.bypassmobile.peripherals.deviceinfo.usb.boot;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.SystemClock;
import android.util.Log;

public class PackageHelper {

    private static final String LOG_TAG = PackageHelper.class.getSimpleName();
    private static final long lastBootTime = System.currentTimeMillis() - SystemClock.elapsedRealtime();

    /**
     * @param context the context of the application you want to check
     * @return true if the package was updated/installed after the last system boot; false otherwise
     */
    public static boolean updatedSinceSystemBoot(Context context) {
        PackageInfo pi = null;
        try {
            pi = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }

        Log.i(LOG_TAG, "pi = " + (pi == null ? "null" : pi.packageName + "; pi.firstInstallTime = " + pi.firstInstallTime + "; pi.lastUpdateTime = " + pi.lastUpdateTime) + "; lastBootTime = " + lastBootTime);
        return pi != null
                && (lastBootTime < pi.firstInstallTime || lastBootTime < pi.lastUpdateTime);
    }
}