一種提高Android應用程式存活率新方法

skyseraph發表於2016-12-19

Android

基礎知識

Android 程式優先順序

1 程式優先順序等級一般分法

Activte process
Visible Process
Service process
Background process
Empty process

2 Service技巧

onStartCommand返回START_STICKY
onDestroy中startself
Service後臺變前置，setForground(true)
android:persistent = “true”

3 程式優先順序號

ProcessList.java

// Adjustment used in certain places where we don't know it yet.
// (Generally this is something that is going to be cached, but we
// don't know the exact value in the cached range to assign yet.)
static final int UNKNOWN_ADJ = 16;

// This is a process only hosting activities that are not visible,
// so it can be killed without any disruption.
static final int CACHED_APP_MAX_ADJ = 15;
static final int CACHED_APP_MIN_ADJ = 9;

// The B list of SERVICE_ADJ -- these are the old and decrepit
// services that aren't as shiny and interesting as the ones in the A list.
static final int SERVICE_B_ADJ = 8;

// This is the process of the previous application that the user was in.
// This process is kept above other things, because it is very common to
// switch back to the previous app.  This is important both for recent
// task switch (toggling between the two top recent apps) as well as normal
// UI flow such as clicking on a URI in the e-mail app to view in the browser,
// and then pressing back to return to e-mail.
static final int PREVIOUS_APP_ADJ = 7;

// This is a process holding the home application -- we want to try
// avoiding killing it, even if it would normally be in the background,
// because the user interacts with it so much.
static final int HOME_APP_ADJ = 6;

// This is a process holding an application service -- killing it will not
// have much of an impact as far as the user is concerned.
static final int SERVICE_ADJ = 5;

// This is a process with a heavy-weight application.  It is in the
// background, but we want to try to avoid killing it.  Value set in
// system/rootdir/init.rc on startup.
static final int HEAVY_WEIGHT_APP_ADJ = 4;

// This is a process currently hosting a backup operation.  Killing it
// is not entirely fatal but is generally a bad idea.
static final int BACKUP_APP_ADJ = 3;

// This is a process only hosting components that are perceptible to the
// user, and we really want to avoid killing them, but they are not
// immediately visible. An example is background music playback.
static final int PERCEPTIBLE_APP_ADJ = 2;

// This is a process only hosting activities that are visible to the
// user, so we'd prefer they don't disappear.
static final int VISIBLE_APP_ADJ = 1;

// This is the process running the current foreground app.  We'd really
// rather not kill it!
static final int FOREGROUND_APP_ADJ = 0;

// This is a process that the system or a persistent process has bound to,
// and indicated it is important.
static final int PERSISTENT_SERVICE_ADJ = -11;

// This is a system persistent process, such as telephony.  Definitely
// don't want to kill it, but doing so is not completely fatal.
static final int PERSISTENT_PROC_ADJ = -12;

// The system process runs at the default adjustment.
static final int SYSTEM_ADJ = -16;

// Special code for native processes that are not being managed by the system (so
// don't have an oom adj assigned by the system).
static final int NATIVE_ADJ = -17;

// Adjustment used in certain places where we don't know it yet.

// (Generally this is something that is going to be cached, but we

// don't know the exact value in the cached range to assign yet.)

static final int UNKNOWN_ADJ = 16;

// This is a process only hosting activities that are not visible,

// so it can be killed without any disruption.

static final int CACHED_APP_MAX_ADJ = 15;

static final int CACHED_APP_MIN_ADJ = 9;

// The B list of SERVICE_ADJ -- these are the old and decrepit

// services that aren't as shiny and interesting as the ones in the A list.

static final int SERVICE_B_ADJ = 8;

// This is the process of the previous application that the user was in.

// This process is kept above other things, because it is very common to

// switch back to the previous app. This is important both for recent

// task switch (toggling between the two top recent apps) as well as normal

// UI flow such as clicking on a URI in the e-mail app to view in the browser,

// and then pressing back to return to e-mail.

static final int PREVIOUS_APP_ADJ = 7;

// This is a process holding the home application -- we want to try

// avoiding killing it, even if it would normally be in the background,

// because the user interacts with it so much.

static final int HOME_APP_ADJ = 6;

// This is a process holding an application service -- killing it will not

// have much of an impact as far as the user is concerned.

static final int SERVICE_ADJ = 5;

// This is a process with a heavy-weight application. It is in the

// background, but we want to try to avoid killing it. Value set in

// system/rootdir/init.rc on startup.

static final int HEAVY_WEIGHT_APP_ADJ = 4;

// This is a process currently hosting a backup operation. Killing it

// is not entirely fatal but is generally a bad idea.

static final int BACKUP_APP_ADJ = 3;

// This is a process only hosting components that are perceptible to the

// user, and we really want to avoid killing them, but they are not

// immediately visible. An example is background music playback.

static final int PERCEPTIBLE_APP_ADJ = 2;

// This is a process only hosting activities that are visible to the

// user, so we'd prefer they don't disappear.

static final int VISIBLE_APP_ADJ = 1;

// This is the process running the current foreground app. We'd really

// rather not kill it!

static final int FOREGROUND_APP_ADJ = 0;

// This is a process that the system or a persistent process has bound to,

// and indicated it is important.

static final int PERSISTENT_SERVICE_ADJ = -11;

// This is a system persistent process, such as telephony. Definitely

// don't want to kill it, but doing so is not completely fatal.

static final int PERSISTENT_PROC_ADJ = -12;

// The system process runs at the default adjustment.

static final int SYSTEM_ADJ = -16;

// Special code for native processes that are not being managed by the system (so

// don't have an oom adj assigned by the system).

static final int NATIVE_ADJ = -17;

Android Low Memory Killer

Android系統記憶體不足時，系統會殺掉一部分程式以釋放空間，誰生誰死的這個生死大權就是由LMK所決定的，這就是Android系統中的Low Memory Killer，其基於Linux的OOM機制,其閾值定義如下面所示的lowmemorykiller檔案中，當然也可以通過系統的init.rc實現自定義。
lowmemorykiller.c

static uint32_t lowmem_debug_level = 1;
static int lowmem_adj[6] = {
    0,
    1,
    6,
    12,
};
static int lowmem_adj_size = 4;
static int lowmem_minfree[6] = {
    3 * 512,    /* 6MB */
    2 * 1024,   /* 8MB */
    4 * 1024,   /* 16MB */
    16 * 1024,  /* 64MB */
};
static int lowmem_minfree_size = 4;

static uint32_t lowmem_debug_level = 1;

static int lowmem_adj[6] = {

12,

};

static int lowmem_adj_size = 4;

static int lowmem_minfree[6] = {

3 * 512, /* 6MB */

2 * 1024, /* 8MB */

4 * 1024, /* 16MB */

16 * 1024, /* 64MB */

};

static int lowmem_minfree_size = 4;

① 在Low Memory Killer中通過程式的oom_adj與佔用記憶體的大小決定要殺死的程式，oom_adj值越小越不容易被殺死。其中，lowmem_minfree是殺程式的時機，誰被殺，則取決於lowmem_adj，具體值得含義參考上面 Android程式優先順序 所述.

② 在init.rc中定義了init程式（系統程式）的oom_adj為-16，其不可能會被殺死(init的PID是1)，而前臺程式是0（這裡的前臺程式是指使用者正在使用的Activity所在的程式），使用者按Home鍵回到桌面時的優先順序是6，普通的Service的程式是8.
init.rc

# Set init and its forked children's oom_adj.
    write /proc/1/oom_adj -16

1 2	# Set init and its forked children's oom_adj. write /proc/1/oom_adj -16

關於Low Memory Killer的具體實現原理可參考Ref-2.

檢視某個App的程式

步驟（手機與PC連線）

adb shell
ps | grep 程式名
cat /proc/pid/oom_adj //其中pid是上述grep得到的程式號

Linux AM命令

am命令：在Android系統中通過adb shell 啟動某個Activity、Service、撥打電話、啟動瀏覽器等操作Android的命令.其原始碼在Am.java中，在shell環境下執行am命令實際是啟動一個執行緒執行Am.java中的主函式（main方法），am命令後跟的引數都會當做執行時引數傳遞到主函式中，主要實現在Am.java的run方法中。

撥打電話
命令：am start -a android.intent.action.CALL -d tel:電話號碼
示例：am start -a android.intent.action.CALL -d tel:10086

開啟一個網頁
命令：am start -a android.intent.action.VIEW -d 網址
示例：am start -a android.intent.action.VIEW -d http://www.skyseraph.com

啟動一個服務
命令：am startservice <服務名稱>
示例：am startservice -n com.android.music/ com.android.music.MediaPlaybackService

NotificationListenerService

“A service that receives calls from the system when new notifications are posted or removed, or their ranking changed.” From Google

用來監聽到通知的傳送以及移除和排名位置變化,如果我們註冊了這個服務，當系統任何一條通知到來或者被移除掉，我們都能通過這個service來監聽到，甚至可以做一些管理工作。

Android賬號和同步機制

屬於Android中較偏冷的知識，具體參考 Ref 3 /4 /5

Android多程式

實現：android:process
好處：一個獨立的程式可以充分利用自己的RAM預算,使其主程式擁有更多的空間處理資源。此外，作業系統對待執行在不同元件中的程式是不一樣的。這意味著，當系統執行在低可用記憶體的條件時，並不是所有的程式都會被殺死
大坑：每一個程式將有自己的Dalvik VM例項,意味著你不能通過這些例項共享資料,至少不是傳統意義上的。例如,靜態欄位在每個程式都有自己的值,而不是你傾向於相信的只有一個值。
更多詳細請參考Ref 9

現有方法

網路連線保活方法

A. GCM
B. 公共的第三方push通道(信鴿等)
C. 自身跟伺服器通過輪詢，或者長連線
具體實現請參考微信架構師楊幹榮的”微信Android客戶端後臺保活經驗分享” （Ref-1）.

雙service(通知欄) 提高程式優先順序

思路：（API level > 18 ）

應用啟動時啟動一個假的Service（FakeService）, startForeground()，傳一個空的Notification
啟動真正的Service（AlwaysLiveService），startForeground()，注意必須相同Notification ID
FakeService stopForeground()

效果：通過adb檢視,執行在後臺的服務其程式號變成了1（優先順序僅次於前臺程式）

風險：Android系統前臺service的一個漏洞，可能在6.0以上系統中修復

實現：核心程式碼如下

AlwaysLiveService 常駐記憶體服務

@Override
   public int onStartCommand(Intent intent, int flags, int startId) {
       startForeground(R.id.notify, new Notification());
       startService(new Intent(this, FakeService.class));
       return super.onStartCommand(intent, flags, startId);
   }

@Override

public int onStartCommand(Intent intent, int flags, int startId) {

startForeground(R.id.notify, new Notification());

startService(new Intent(this, FakeService.class));

return super.onStartCommand(intent, flags, startId);

}

FakeService 臨時服務

public class FakeService extends Service {	
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        startForeground(R.id.notify, new Notification());
        stopSelf();
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        stopForeground(true);
        super.onDestroy();
    }
}

public class FakeService extends Service {

@Nullable

@Override

public IBinder onBind(Intent intent) {

return null;

}

@Override

public int onStartCommand(Intent intent, int flags, int startId) {

startForeground(R.id.notify, new Notification());

stopSelf();

return super.onStartCommand(intent, flags, startId);

}

@Override

public void onDestroy() {

stopForeground(true);

super.onDestroy();

}

Service及時拉起

AlarmReceiver， ConnectReceiver，BootReceiver等

Service設定（見上面基礎部分）
通過監聽系統廣播，如開機，鎖屏，亮屏等重新啟動服務
通過alarm定時器，啟動服務

守護程式/程式互拉

在分析360手機助手app時，發現其擁有N多個程式，一個程式kill後會被其它未kill的程式拉起，這也是一種思路吧，雖然有點流氓~
守護程式一般有這樣兩種方式：

多個java程式守護互拉
底層C守護程式拉起App上層/java程式

Linux Am命令開啟後臺程式

一種底層實現讓程式不被殺死的方法，在Android4.4以上可能有相容性問題，具體參考Ref-7

NotificationListenerService通知

一種需要使用者允許特定許可權的系統拉起方式，4.3以上系統

前臺浮窗

有朋友提出一種應用退出後啟動一個不可互動的浮窗，個人覺得這種方法是無效的，讀者有興趣可以一試

新方法(AccountSync)

思路

利用Android系統提供的賬號和同步機制實現

效果

通過adb檢視,執行在後臺的服務其程式號變成了1（優先順序僅次於前臺程式），能提高程式優先順序，對比如下圖

正常情況

採用AccountSyncAdapter方法後

程式被系統kill後，可以由syn拉起

風險

SyncAdapter時間進度不高，往往會因為手機處於休眠狀態，而時間往後調整，同步間隔最低為1分鐘
使用者可以單獨停止或者刪除，有些手機賬號預設是不同步的，需要手動開啟

實現 (核心程式碼)

1 建立資料同步系統（ContentProvider）

通過一個ContentProvider用來作資料同步，由於並沒有實際資料同步，所以此處就直接建立一個空的ContentProvider即可

public class XXAccountProvider extends ContentProvider {
    public static final String AUTHORITY = "包名.provider";
    public static final String CONTENT_URI_BASE = "content://" + AUTHORITY;
    public static final String TABLE_NAME = "data";
    public static final Uri CONTENT_URI = Uri.parse(CONTENT_URI_BASE + "/" + TABLE_NAME);

    @Override
    public boolean onCreate() {
        return true;
    }

    @Nullable
    @Override
    public Cursor query(Uri uri, String[] projection, String selection,
                        String[] selectionArgs, String sortOrder) {
        return null;
    }

    @Nullable
    @Override
    public String getType(Uri uri) {
        return new String();
    }

    @Nullable
    @Override
    public Uri insert(Uri uri, ContentValues values) {
        return null;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        return 0;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        return 0;
    }
}

public class XXAccountProvider extends ContentProvider {

public static final String AUTHORITY = "包名.provider";

public static final String CONTENT_URI_BASE = "content://" + AUTHORITY;

public static final String TABLE_NAME = "data";

public static final Uri CONTENT_URI = Uri.parse(CONTENT_URI_BASE + "/" + TABLE_NAME);

@Override

public boolean onCreate() {

return true;

}

@Nullable

@Override

public Cursor query(Uri uri, String[] projection, String selection,

String[] selectionArgs, String sortOrder) {

return null;

}

@Nullable

@Override

public String getType(Uri uri) {

return new String();

}

@Nullable

@Override

public Uri insert(Uri uri, ContentValues values) {

return null;

}

@Override

public int delete(Uri uri, String selection, String[] selectionArgs) {

return 0;

}

@Override

public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {

return 0;

}

然後再Manifest中宣告

<provider
	android:name="**.XXAccountProvider"
	android:authorities="@string/account_auth_provider"
	android:exported="false"
	android:syncable="true"/>

<provider

android:name="**.XXAccountProvider"

android:authorities="@string/account_auth_provider"

android:exported="false"

android:syncable="true"/>

2 建立Sync系統 (SyncAdapter)

通過實現SyncAdapter這個系統服務後, 利用系統的定時器對程式資料ContentProvider進行更新，具體步驟為：

建立Sync服務

public class XXSyncService extends Service {
    private static final Object sSyncAdapterLock = new Object();
    private static XXSyncAdapter sSyncAdapter = null;
    @Override
    public void onCreate() {
        synchronized (sSyncAdapterLock) {
            if (sSyncAdapter == null) {
                sSyncAdapter = new XXSyncAdapter(getApplicationContext(), true);
            }
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        return sSyncAdapter.getSyncAdapterBinder();
    }

    static class XXSyncAdapter extends AbstractThreadedSyncAdapter {
        public XXSyncAdapter(Context context, boolean autoInitialize) {
            super(context, autoInitialize);
        }
        @Override
        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
            getContext().getContentResolver().notifyChange(XXAccountProvider.CONTENT_URI, null, false);
        }
    }
}

public class XXSyncService extends Service {

private static final Object sSyncAdapterLock = new Object();

private static XXSyncAdapter sSyncAdapter = null;

@Override

public void onCreate() {

synchronized (sSyncAdapterLock) {

if (sSyncAdapter == null) {

sSyncAdapter = new XXSyncAdapter(getApplicationContext(), true);

}

@Override

public IBinder onBind(Intent intent) {

return sSyncAdapter.getSyncAdapterBinder();

}

static class XXSyncAdapter extends AbstractThreadedSyncAdapter {

public XXSyncAdapter(Context context, boolean autoInitialize) {

super(context, autoInitialize);

}

@Override

public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {

getContext().getContentResolver().notifyChange(XXAccountProvider.CONTENT_URI, null, false);

}

宣告Sync服務

<service
	android:name="**.XXSyncService"
	android:exported="true"
	android:process=":core">
	<intent-filter>
		<action
			android:name="android.content.SyncAdapter"/>
	</intent-filter>
	<meta-data
		android:name="android.content.SyncAdapter"
		android:resource="@xml/sync_adapter"/>
</service>

<service

android:name="**.XXSyncService"

android:exported="true"

android:process=":core">

<intent-filter>

<action

android:name="android.content.SyncAdapter"/>

</intent-filter>

<meta-data

android:name="android.content.SyncAdapter"

android:resource="@xml/sync_adapter"/>

</service>

其中sync_adapter為：

<sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
              android:accountType="@string/account_auth_type"
              android:allowParallelSyncs="false"
              android:contentAuthority="@string/account_auth_provide"
              android:isAlwaysSyncable="true"
              android:supportsUploading="false"
              android:userVisible="true"/>

<sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"

android:accountType="@string/account_auth_type"

android:allowParallelSyncs="false"

android:contentAuthority="@string/account_auth_provide"

android:isAlwaysSyncable="true"

android:supportsUploading="false"

android:userVisible="true"/>

引數說明：

android:contentAuthority 指定要同步的ContentProvider在其AndroidManifest.xml檔案中有個android:authorities屬性。
android:accountType 表示進行同步的賬號的型別。
android:userVisible 設定是否在“設定”中顯示
android:supportsUploading 設定是否必須notifyChange通知才能同步
android:allowParallelSyncs 是否支援多賬號同時同步
android:isAlwaysSyncable 設定所有賬號的isSyncable為1
android:syncAdapterSettingsAction 指定一個可以設定同步的activity的Action。

賬戶呼叫Sync服務
首先配置好Account（第三步），然後再通過ContentProvider實現
手動更新

public void triggerRefresh() {
	Bundle b = new Bundle();
	b.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);
	b.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true);
	ContentResolver.requestSync(
			account,
			CONTENT_AUTHORITY,
			b);
}

public void triggerRefresh() {

Bundle b = new Bundle();

b.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);

b.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true);

ContentResolver.requestSync(

account,

CONTENT_AUTHORITY,

b);

}

新增賬號

Account account = AccountService.GetAccount(); 
AccountManager accountManager = (AccountManager) context.getSystemService(Context.ACCOUNT_SERVICE);
accountManager.addAccountExplicitly(...)

Account account = AccountService.GetAccount();

AccountManager accountManager = (AccountManager) context.getSystemService(Context.ACCOUNT_SERVICE);

accountManager.addAccountExplicitly(...)

同步週期設定

ContentResolver.setIsSyncable(account, CONTENT_AUTHORITY, 1);
ContentResolver.setSyncAutomatically(account, CONTENT_AUTHORITY, true);
ContentResolver.addPeriodicSync(account, CONTENT_AUTHORITY, new Bundle(), SYNC_FREQUENCY);

ContentResolver.setIsSyncable(account, CONTENT_AUTHORITY, 1);

ContentResolver.setSyncAutomatically(account, CONTENT_AUTHORITY, true);

ContentResolver.addPeriodicSync(account, CONTENT_AUTHORITY, new Bundle(), SYNC_FREQUENCY);

3 建立賬號系統 (Account Authenticator)

通過建立Account賬號，並關聯SyncAdapter服務實現同步

建立Account服務

public class XXAuthService extends Service {
    private XXAuthenticator mAuthenticator;

    @Override
    public void onCreate() {
        mAuthenticator = new XXAuthenticator(this);
    }

    private XXAuthenticator getAuthenticator() {
        if (mAuthenticator == null)
            mAuthenticator = new XXAuthenticator(this);
        return mAuthenticator;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return getAuthenticator().getIBinder();
    }

    class XXAuthenticator extends AbstractAccountAuthenticator {
        private final Context context;
        private AccountManager accountManager;
        public XXAuthenticator(Context context) {
            super(context);
            this.context = context;
            accountManager = AccountManager.get(context);
        }

        @Override
        public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options)
                throws NetworkErrorException {
			// 新增賬號 示例程式碼
            final Bundle bundle = new Bundle();
            final Intent intent = new Intent(context, AuthActivity.class);
            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
            bundle.putParcelable(AccountManager.KEY_INTENT, intent);
            return bundle;
        }

        @Override
        public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options)
                throws NetworkErrorException {
			// 認證 示例程式碼
            String authToken = accountManager.peekAuthToken(account, getString(R.string.account_token_type));
            //if not, might be expired, register again
            if (TextUtils.isEmpty(authToken)) {
                final String password = accountManager.getPassword(account);
                if (password != null) {
                    //get new token
					authToken = account.name + password;
                }
            }
            //without password, need to sign again
            final Bundle bundle = new Bundle();
            if (!TextUtils.isEmpty(authToken)) {
                bundle.putString(AccountManager.KEY_ACCOUNT_NAME, account.name);
                bundle.putString(AccountManager.KEY_ACCOUNT_TYPE, account.type);
                bundle.putString(AccountManager.KEY_AUTHTOKEN, authToken);
                return bundle;
            }

            //no account data at all, need to do a sign
            final Intent intent = new Intent(context, AuthActivity.class);
            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
            intent.putExtra(AuthActivity.ARG_ACCOUNT_NAME, account.name);
            bundle.putParcelable(AccountManager.KEY_INTENT, intent);
            return bundle;
        }

        @Override
        public String getAuthTokenLabel(String authTokenType) {
//            throw new UnsupportedOperationException();
            return null;
        }

        @Override
        public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {
            return null;
        }

        @Override
        public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options)
                throws NetworkErrorException {
            return null;
        }

        @Override
        public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options)
                throws NetworkErrorException {
            return null;
        }

        @Override
        public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features)
                throws NetworkErrorException {
            return null;
        }
    }
}

public class XXAuthService extends Service {

private XXAuthenticator mAuthenticator;

@Override

public void onCreate() {

mAuthenticator = new XXAuthenticator(this);

}

private XXAuthenticator getAuthenticator() {

if (mAuthenticator == null)

mAuthenticator = new XXAuthenticator(this);

return mAuthenticator;

}

@Override

public IBinder onBind(Intent intent) {

return getAuthenticator().getIBinder();

}

class XXAuthenticator extends AbstractAccountAuthenticator {

private final Context context;

private AccountManager accountManager;

public XXAuthenticator(Context context) {

super(context);

this.context = context;

accountManager = AccountManager.get(context);

}

@Override

public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options)

throws NetworkErrorException {

// 新增賬號示例程式碼

final Bundle bundle = new Bundle();

final Intent intent = new Intent(context, AuthActivity.class);

intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);

bundle.putParcelable(AccountManager.KEY_INTENT, intent);

return bundle;

}

@Override

public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options)

throws NetworkErrorException {

// 認證示例程式碼

String authToken = accountManager.peekAuthToken(account, getString(R.string.account_token_type));

//if not, might be expired, register again

if (TextUtils.isEmpty(authToken)) {

final String password = accountManager.getPassword(account);

if (password != null) {

//get new token

authToken = account.name + password;

}

//without password, need to sign again

final Bundle bundle = new Bundle();

if (!TextUtils.isEmpty(authToken)) {

bundle.putString(AccountManager.KEY_ACCOUNT_NAME, account.name);

bundle.putString(AccountManager.KEY_ACCOUNT_TYPE, account.type);

bundle.putString(AccountManager.KEY_AUTHTOKEN, authToken);

return bundle;

}

//no account data at all, need to do a sign

final Intent intent = new Intent(context, AuthActivity.class);

intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);

intent.putExtra(AuthActivity.ARG_ACCOUNT_NAME, account.name);

bundle.putParcelable(AccountManager.KEY_INTENT, intent);

return bundle;

}

@Override

public String getAuthTokenLabel(String authTokenType) {

// throw new UnsupportedOperationException();

return null;

}

@Override

public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {

return null;

}

@Override

public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options)

throws NetworkErrorException {

return null;

}

@Override

public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options)

throws NetworkErrorException {

return null;

}

@Override

public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features)

throws NetworkErrorException {

return null;

}

宣告Account服務

<service
	android:name="**.XXAuthService"
	android:exported="true"
	android:process=":core">
	<intent-filter>
		<action
			android:name="android.accounts.AccountAuthenticator"/>
	</intent-filter>
	<meta-data
		android:name="android.accounts.AccountAuthenticator"
		android:resource="@xml/authenticator"/>
</service>

<service

android:name="**.XXAuthService"

android:exported="true"

android:process=":core">

<intent-filter>

<action

android:name="android.accounts.AccountAuthenticator"/>

</intent-filter>

<meta-data

android:name="android.accounts.AccountAuthenticator"

android:resource="@xml/authenticator"/>

</service>

其中authenticator為：

<?xml version="1.0" encoding="utf-8"?>
<account-authenticator xmlns:android="http://schemas.android.com/apk/res/android"
    android:accountType="@string/account_auth_type"
    android:icon="@drawable/icon"
    android:smallIcon="@drawable/icon"
    android:label="@string/app_name"
/>

<?xml version="1.0" encoding="utf-8"?>

<account-authenticator xmlns:android="http://schemas.android.com/apk/res/android"

android:accountType="@string/account_auth_type"

android:icon="@drawable/icon"

android:smallIcon="@drawable/icon"

android:label="@string/app_name"

使用Account服務
同SyncAdapter，通過AccountManager使用
- 申請Token主要是通過 AccountManager.getAuthToken)系列方法
- 新增賬號則通過 AccountManager.addAccount)
- 檢視是否存在賬號通過 AccountManager.getAccountsByType)

Refs

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最優雅退出 Android 應用程式的 6 種方式
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使用 Kotlin 構建 MVVM 應用程式—提高篇：Dagger-Android
2019-02-26
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一種有效應對側通道記憶體攻擊的新方法
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2010-09-13
DeveloperAI模式
一種國際化Qt應用程式的方法
2019-02-16
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提高Spring Data JPA應用程式的效能
2019-01-10
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2017-03-16
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2014-07-31
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用PHP編寫Android應用程式
2019-05-11
PHPAndroid
提高Web應用程式開發的7個技巧
2011-01-07
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提高 ASP.NET Web 應用效能的 24 種方法和技巧
2016-01-22
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下沉式通知的一種實現 | Android懸浮窗Window應用
2020-01-06
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2020-04-05
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2011-06-09
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2020-01-10
JavaScript
10款提高效率的iPhone應用程式
2010-10-27
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Android應用程式程式啟動過程
2017-03-29
Android
[android]使用jdb除錯android應用程式
2012-06-20
Android除錯
啟動另外的一個應用程式的Activity（三種方式）
2016-03-22
Android應用啟動優化:一種DelayLoad的實現和原理
2015-11-22
Android優化
使用Android Studio建立第一個Hello World應用程式
2015-11-16
Android
Java四種引用解析以及在Android的應用
2017-12-19
JavaAndroid
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2018-09-12
Web
【edobnet】利用.Net 執行緒池提高應用程式效能.
2008-06-16
執行緒
提高Linux系統效能加速網路應用程式(轉)
2007-08-16
Linux
如何構建 Android MVVM 應用程式
2016-06-25
AndroidMVVM
Team Queue （佇列的一種應用）
2019-05-10
佇列
MySQL壓縮表的一種應用
2015-06-03
MySql
ASP.NET 2.0 本地化功能：本地化 Web 應用程式的新方法
2006-01-18
ASP.NETWeb
Qt——應用程式打包（一）
2017-02-23
QT
Android應用啟動優化:一種DelayLoad的實現和原理(下篇)
2016-01-14
Android優化

一種提高Android應用程式存活率新方法

基礎知識

Android 程式優先順序

Android Low Memory Killer

檢視某個App的程式

Linux AM命令

NotificationListenerService

Android賬號和同步機制

Android多程式

現有方法

網路連線保活方法

雙service(通知欄) 提高程式優先順序

Service及時拉起

守護程式/程式互拉

Linux Am命令開啟後臺程式

NotificationListenerService通知

前臺浮窗

新方法(AccountSync)

思路

效果

風險

實現 (核心程式碼)

Refs

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