Android example source code file (BatteryService.java)

This example Android source code file (BatteryService.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, app, battery_discharge_info, battery_plugged_none, battery_scale, battery_stats_service_name, batteryservice, content, dropboxmanager, dumpsys_args, file, intent, io, local_logv, os, override, remoteexception, string, ueventobserver, util

The BatteryService.java Android example source code

/*
 * Copyright (C) 2006 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.server;

import com.android.internal.app.IBatteryStats;
import com.android.server.am.BatteryStatsService;

import android.app.ActivityManagerNative;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.BatteryManager;
import android.os.Binder;
import android.os.IBinder;
import android.os.DropBoxManager;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.SystemClock;
import android.os.UEventObserver;
import android.provider.Settings;
import android.util.EventLog;
import android.util.Slog;

import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;


/**
 * <p>BatteryService monitors the charging status, and charge level of the device
 * battery.  When these values change this service broadcasts the new values
 * to all {@link android.content.BroadcastReceiver IntentReceivers} that are
 * watching the {@link android.content.Intent#ACTION_BATTERY_CHANGED
 * BATTERY_CHANGED} action.</p>
 * <p>The new values are stored in the Intent data and can be retrieved by
 * calling {@link android.content.Intent#getExtra Intent.getExtra} with the
 * following keys:</p>
 * <p>"scale" - int, the maximum value for the charge level

 * <p>"level" - int, charge level, from 0 through "scale" inclusive

 * <p>"status" - String, the current charging status.

 * <p>"health" - String, the current battery health.

 * <p>"present" - boolean, true if the battery is present

 * <p>"icon-small" - int, suggested small icon to use for this state

 * <p>"plugged" - int, 0 if the device is not plugged in; 1 if plugged
 * into an AC power adapter; 2 if plugged in via USB.</p>
 * <p>"voltage" - int, current battery voltage in millivolts

 * <p>"temperature" - int, current battery temperature in tenths of
 * a degree Centigrade</p>
 * <p>"technology" - String, the type of battery installed, e.g. "Li-ion"

 */
class BatteryService extends Binder {
    private static final String TAG = BatteryService.class.getSimpleName();

    private static final boolean LOCAL_LOGV = false;

    static final int BATTERY_SCALE = 100;    // battery capacity is a percentage

    // Used locally for determining when to make a last ditch effort to log
    // discharge stats before the device dies.
    private static final int CRITICAL_BATTERY_LEVEL = 4;

    private static final int DUMP_MAX_LENGTH = 24 * 1024;
    private static final String[] DUMPSYS_ARGS = new String[] { "--checkin", "-u" };
    private static final String BATTERY_STATS_SERVICE_NAME = "batteryinfo";

    private static final String DUMPSYS_DATA_PATH = "/data/system/";

    // This should probably be exposed in the API, though it's not critical
    private static final int BATTERY_PLUGGED_NONE = 0;

    private final Context mContext;
    private final IBatteryStats mBatteryStats;

    private boolean mAcOnline;
    private boolean mUsbOnline;
    private int mBatteryStatus;
    private int mBatteryHealth;
    private boolean mBatteryPresent;
    private int mBatteryLevel;
    private int mBatteryVoltage;
    private int mBatteryTemperature;
    private String mBatteryTechnology;
    private boolean mBatteryLevelCritical;

    private int mLastBatteryStatus;
    private int mLastBatteryHealth;
    private boolean mLastBatteryPresent;
    private int mLastBatteryLevel;
    private int mLastBatteryVoltage;
    private int mLastBatteryTemperature;
    private boolean mLastBatteryLevelCritical;

    private int mLowBatteryWarningLevel;
    private int mLowBatteryCloseWarningLevel;

    private int mPlugType;
    private int mLastPlugType = -1; // Extra state so we can detect first run

    private long mDischargeStartTime;
    private int mDischargeStartLevel;

    private boolean mSentLowBatteryBroadcast = false;

    public BatteryService(Context context) {
        mContext = context;
        mBatteryStats = BatteryStatsService.getService();

        mLowBatteryWarningLevel = mContext.getResources().getInteger(
                com.android.internal.R.integer.config_lowBatteryWarningLevel);
        mLowBatteryCloseWarningLevel = mContext.getResources().getInteger(
                com.android.internal.R.integer.config_lowBatteryCloseWarningLevel);

        mUEventObserver.startObserving("SUBSYSTEM=power_supply");

        // set initial status
        update();
    }

    final boolean isPowered() {
        // assume we are powered if battery state is unknown so the "stay on while plugged in" option will work.
        return (mAcOnline || mUsbOnline || mBatteryStatus == BatteryManager.BATTERY_STATUS_UNKNOWN);
    }

    final boolean isPowered(int plugTypeSet) {
        // assume we are powered if battery state is unknown so
        // the "stay on while plugged in" option will work.
        if (mBatteryStatus == BatteryManager.BATTERY_STATUS_UNKNOWN) {
            return true;
        }
        if (plugTypeSet == 0) {
            return false;
        }
        int plugTypeBit = 0;
        if (mAcOnline) {
            plugTypeBit |= BatteryManager.BATTERY_PLUGGED_AC;
        }
        if (mUsbOnline) {
            plugTypeBit |= BatteryManager.BATTERY_PLUGGED_USB;
        }
        return (plugTypeSet & plugTypeBit) != 0;
    }

    final int getPlugType() {
        return mPlugType;
    }

    private UEventObserver mUEventObserver = new UEventObserver() {
        @Override
        public void onUEvent(UEventObserver.UEvent event) {
            update();
        }
    };

    // returns battery level as a percentage
    final int getBatteryLevel() {
        return mBatteryLevel;
    }

    void systemReady() {
        // check our power situation now that it is safe to display the shutdown dialog.
        shutdownIfNoPower();
        shutdownIfOverTemp();
    }

    private final void shutdownIfNoPower() {
        // shut down gracefully if our battery is critically low and we are not powered.
        // wait until the system has booted before attempting to display the shutdown dialog.
        if (mBatteryLevel == 0 && !isPowered() && ActivityManagerNative.isSystemReady()) {
            Intent intent = new Intent(Intent.ACTION_REQUEST_SHUTDOWN);
            intent.putExtra(Intent.EXTRA_KEY_CONFIRM, false);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            mContext.startActivity(intent);
        }
    }

    private final void shutdownIfOverTemp() {
        // shut down gracefully if temperature is too high (> 68.0C)
        // wait until the system has booted before attempting to display the shutdown dialog.
        if (mBatteryTemperature > 680 && ActivityManagerNative.isSystemReady()) {
            Intent intent = new Intent(Intent.ACTION_REQUEST_SHUTDOWN);
            intent.putExtra(Intent.EXTRA_KEY_CONFIRM, false);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            mContext.startActivity(intent);
        }
    }

    private native void native_update();

    private synchronized final void update() {
        native_update();

        boolean logOutlier = false;
        long dischargeDuration = 0;

        shutdownIfNoPower();
        shutdownIfOverTemp();

        mBatteryLevelCritical = mBatteryLevel <= CRITICAL_BATTERY_LEVEL;
        if (mAcOnline) {
            mPlugType = BatteryManager.BATTERY_PLUGGED_AC;
        } else if (mUsbOnline) {
            mPlugType = BatteryManager.BATTERY_PLUGGED_USB;
        } else {
            mPlugType = BATTERY_PLUGGED_NONE;
        }
        if (mBatteryStatus != mLastBatteryStatus ||
                mBatteryHealth != mLastBatteryHealth ||
                mBatteryPresent != mLastBatteryPresent ||
                mBatteryLevel != mLastBatteryLevel ||
                mPlugType != mLastPlugType ||
                mBatteryVoltage != mLastBatteryVoltage ||
                mBatteryTemperature != mLastBatteryTemperature) {

            if (mPlugType != mLastPlugType) {
                if (mLastPlugType == BATTERY_PLUGGED_NONE) {
                    // discharging -> charging

                    // There's no value in this data unless we've discharged at least once and the
                    // battery level has changed; so don't log until it does.
                    if (mDischargeStartTime != 0 && mDischargeStartLevel != mBatteryLevel) {
                        dischargeDuration = SystemClock.elapsedRealtime() - mDischargeStartTime;
                        logOutlier = true;
                        EventLog.writeEvent(EventLogTags.BATTERY_DISCHARGE, dischargeDuration,
                                mDischargeStartLevel, mBatteryLevel);
                        // make sure we see a discharge event before logging again
                        mDischargeStartTime = 0;
                    }
                } else if (mPlugType == BATTERY_PLUGGED_NONE) {
                    // charging -> discharging or we just powered up
                    mDischargeStartTime = SystemClock.elapsedRealtime();
                    mDischargeStartLevel = mBatteryLevel;
                }
            }
            if (mBatteryStatus != mLastBatteryStatus ||
                    mBatteryHealth != mLastBatteryHealth ||
                    mBatteryPresent != mLastBatteryPresent ||
                    mPlugType != mLastPlugType) {
                EventLog.writeEvent(EventLogTags.BATTERY_STATUS,
                        mBatteryStatus, mBatteryHealth, mBatteryPresent ? 1 : 0,
                        mPlugType, mBatteryTechnology);
            }
            if (mBatteryLevel != mLastBatteryLevel ||
                    mBatteryVoltage != mLastBatteryVoltage ||
                    mBatteryTemperature != mLastBatteryTemperature) {
                EventLog.writeEvent(EventLogTags.BATTERY_LEVEL,
                        mBatteryLevel, mBatteryVoltage, mBatteryTemperature);
            }
            if (mBatteryLevel != mLastBatteryLevel && mPlugType == BATTERY_PLUGGED_NONE) {
                // If the battery level has changed and we are on battery, update the current level.
                // This is used for discharge cycle tracking so this shouldn't be updated while the
                // battery is charging.
                try {
                    mBatteryStats.recordCurrentLevel(mBatteryLevel);
                } catch (RemoteException e) {
                    // Should never happen.
                }
            }
            if (mBatteryLevelCritical && !mLastBatteryLevelCritical &&
                    mPlugType == BATTERY_PLUGGED_NONE) {
                // We want to make sure we log discharge cycle outliers
                // if the battery is about to die.
                dischargeDuration = SystemClock.elapsedRealtime() - mDischargeStartTime;
                logOutlier = true;
            }

            final boolean plugged = mPlugType != BATTERY_PLUGGED_NONE;
            final boolean oldPlugged = mLastPlugType != BATTERY_PLUGGED_NONE;

            /* The ACTION_BATTERY_LOW broadcast is sent in these situations:
             * - is just un-plugged (previously was plugged) and battery level is
             *   less than or equal to WARNING, or
             * - is not plugged and battery level falls to WARNING boundary
             *   (becomes <= mLowBatteryWarningLevel).
             */
            final boolean sendBatteryLow = !plugged
                && mBatteryStatus != BatteryManager.BATTERY_STATUS_UNKNOWN
                && mBatteryLevel <= mLowBatteryWarningLevel
                && (oldPlugged || mLastBatteryLevel > mLowBatteryWarningLevel);

            sendIntent();

            // Separate broadcast is sent for power connected / not connected
            // since the standard intent will not wake any applications and some
            // applications may want to have smart behavior based on this.
            Intent statusIntent = new Intent();
            statusIntent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
            if (mPlugType != 0 && mLastPlugType == 0) {
                statusIntent.setAction(Intent.ACTION_POWER_CONNECTED);
                mContext.sendBroadcast(statusIntent);
            }
            else if (mPlugType == 0 && mLastPlugType != 0) {
                statusIntent.setAction(Intent.ACTION_POWER_DISCONNECTED);
                mContext.sendBroadcast(statusIntent);
            }

            if (sendBatteryLow) {
                mSentLowBatteryBroadcast = true;
                statusIntent.setAction(Intent.ACTION_BATTERY_LOW);
                mContext.sendBroadcast(statusIntent);
            } else if (mSentLowBatteryBroadcast && mLastBatteryLevel >= mLowBatteryCloseWarningLevel) {
                mSentLowBatteryBroadcast = false;
                statusIntent.setAction(Intent.ACTION_BATTERY_OKAY);
                mContext.sendBroadcast(statusIntent);
            }

            // This needs to be done after sendIntent() so that we get the lastest battery stats.
            if (logOutlier && dischargeDuration != 0) {
                logOutlier(dischargeDuration);
            }

            mLastBatteryStatus = mBatteryStatus;
            mLastBatteryHealth = mBatteryHealth;
            mLastBatteryPresent = mBatteryPresent;
            mLastBatteryLevel = mBatteryLevel;
            mLastPlugType = mPlugType;
            mLastBatteryVoltage = mBatteryVoltage;
            mLastBatteryTemperature = mBatteryTemperature;
            mLastBatteryLevelCritical = mBatteryLevelCritical;
        }
    }

    private final void sendIntent() {
        //  Pack up the values and broadcast them to everyone
        Intent intent = new Intent(Intent.ACTION_BATTERY_CHANGED);
        intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY
                | Intent.FLAG_RECEIVER_REPLACE_PENDING);
        try {
            mBatteryStats.setOnBattery(mPlugType == BATTERY_PLUGGED_NONE, mBatteryLevel);
        } catch (RemoteException e) {
            // Should never happen.
        }

        int icon = getIcon(mBatteryLevel);

        intent.putExtra(BatteryManager.EXTRA_STATUS, mBatteryStatus);
        intent.putExtra(BatteryManager.EXTRA_HEALTH, mBatteryHealth);
        intent.putExtra(BatteryManager.EXTRA_PRESENT, mBatteryPresent);
        intent.putExtra(BatteryManager.EXTRA_LEVEL, mBatteryLevel);
        intent.putExtra(BatteryManager.EXTRA_SCALE, BATTERY_SCALE);
        intent.putExtra(BatteryManager.EXTRA_ICON_SMALL, icon);
        intent.putExtra(BatteryManager.EXTRA_PLUGGED, mPlugType);
        intent.putExtra(BatteryManager.EXTRA_VOLTAGE, mBatteryVoltage);
        intent.putExtra(BatteryManager.EXTRA_TEMPERATURE, mBatteryTemperature);
        intent.putExtra(BatteryManager.EXTRA_TECHNOLOGY, mBatteryTechnology);

        if (false) {
            Slog.d(TAG, "updateBattery level:" + mBatteryLevel +
                    " scale:" + BATTERY_SCALE + " status:" + mBatteryStatus +
                    " health:" + mBatteryHealth +  " present:" + mBatteryPresent +
                    " voltage: " + mBatteryVoltage +
                    " temperature: " + mBatteryTemperature +
                    " technology: " + mBatteryTechnology +
                    " AC powered:" + mAcOnline + " USB powered:" + mUsbOnline +
                    " icon:" + icon );
        }

        ActivityManagerNative.broadcastStickyIntent(intent, null);
    }

    private final void logBatteryStats() {
        IBinder batteryInfoService = ServiceManager.getService(BATTERY_STATS_SERVICE_NAME);
        if (batteryInfoService == null) return;

        DropBoxManager db = (DropBoxManager) mContext.getSystemService(Context.DROPBOX_SERVICE);
        if (db == null || !db.isTagEnabled("BATTERY_DISCHARGE_INFO")) return;

        File dumpFile = null;
        FileOutputStream dumpStream = null;
        try {
            // dump the service to a file
            dumpFile = new File(DUMPSYS_DATA_PATH + BATTERY_STATS_SERVICE_NAME + ".dump");
            dumpStream = new FileOutputStream(dumpFile);
            batteryInfoService.dump(dumpStream.getFD(), DUMPSYS_ARGS);
            dumpStream.getFD().sync();

            // add dump file to drop box
            db.addFile("BATTERY_DISCHARGE_INFO", dumpFile, DropBoxManager.IS_TEXT);
        } catch (RemoteException e) {
            Slog.e(TAG, "failed to dump battery service", e);
        } catch (IOException e) {
            Slog.e(TAG, "failed to write dumpsys file", e);
        } finally {
            // make sure we clean up
            if (dumpStream != null) {
                try {
                    dumpStream.close();
                } catch (IOException e) {
                    Slog.e(TAG, "failed to close dumpsys output stream");
                }
            }
            if (dumpFile != null && !dumpFile.delete()) {
                Slog.e(TAG, "failed to delete temporary dumpsys file: "
                        + dumpFile.getAbsolutePath());
            }
        }
    }

    private final void logOutlier(long duration) {
        ContentResolver cr = mContext.getContentResolver();
        String dischargeThresholdString = Settings.Secure.getString(cr,
                Settings.Secure.BATTERY_DISCHARGE_THRESHOLD);
        String durationThresholdString = Settings.Secure.getString(cr,
                Settings.Secure.BATTERY_DISCHARGE_DURATION_THRESHOLD);

        if (dischargeThresholdString != null && durationThresholdString != null) {
            try {
                long durationThreshold = Long.parseLong(durationThresholdString);
                int dischargeThreshold = Integer.parseInt(dischargeThresholdString);
                if (duration <= durationThreshold &&
                        mDischargeStartLevel - mBatteryLevel >= dischargeThreshold) {
                    // If the discharge cycle is bad enough we want to know about it.
                    logBatteryStats();
                }
                if (LOCAL_LOGV) Slog.v(TAG, "duration threshold: " + durationThreshold +
                        " discharge threshold: " + dischargeThreshold);
                if (LOCAL_LOGV) Slog.v(TAG, "duration: " + duration + " discharge: " +
                        (mDischargeStartLevel - mBatteryLevel));
            } catch (NumberFormatException e) {
                Slog.e(TAG, "Invalid DischargeThresholds GService string: " +
                        durationThresholdString + " or " + dischargeThresholdString);
                return;
            }
        }
    }

    private final int getIcon(int level) {
        if (mBatteryStatus == BatteryManager.BATTERY_STATUS_CHARGING) {
            return com.android.internal.R.drawable.stat_sys_battery_charge;
        } else if (mBatteryStatus == BatteryManager.BATTERY_STATUS_DISCHARGING ||
                mBatteryStatus == BatteryManager.BATTERY_STATUS_NOT_CHARGING ||
                mBatteryStatus == BatteryManager.BATTERY_STATUS_FULL) {
            return com.android.internal.R.drawable.stat_sys_battery;
        } else {
            return com.android.internal.R.drawable.stat_sys_battery_unknown;
        }
    }

    @Override
    protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
                != PackageManager.PERMISSION_GRANTED) {

            pw.println("Permission Denial: can't dump Battery service from from pid="
                    + Binder.getCallingPid()
                    + ", uid=" + Binder.getCallingUid());
            return;
        }

        synchronized (this) {
            pw.println("Current Battery Service state:");
            pw.println("  AC powered: " + mAcOnline);
            pw.println("  USB powered: " + mUsbOnline);
            pw.println("  status: " + mBatteryStatus);
            pw.println("  health: " + mBatteryHealth);
            pw.println("  present: " + mBatteryPresent);
            pw.println("  level: " + mBatteryLevel);
            pw.println("  scale: " + BATTERY_SCALE);
            pw.println("  voltage:" + mBatteryVoltage);
            pw.println("  temperature: " + mBatteryTemperature);
            pw.println("  technology: " + mBatteryTechnology);
        }
    }
}