SharedProvider一個(gè)SharedPreferences 多進(jìn)程解決方案骇笔，內(nèi)部使用ContentProvider方式實(shí)現(xiàn)榄审。

由于app采用了多進(jìn)程的方式，踩了SharedPreferences的坑。所以決定用ContentProvider來實(shí)現(xiàn)一個(gè)自己的SharedPreferences。
github項(xiàng)目地址

坑1：SharedPreferences最大的坑就是多進(jìn)程讀取

描述問題：我在A進(jìn)程中寫入U(xiǎn)serId锰蓬，在B進(jìn)程中讀取UserId進(jìn)行網(wǎng)絡(luò)訪問，有的時(shí)候會(huì)出現(xiàn)莫名其妙的問題眯漩，讀取的UserId不是null就是上一次的UserId芹扭。
查閱官方文檔：Android在api11的時(shí)候加入MODE_MULTI_PROCESS來支持多進(jìn)程，但是在api23的時(shí)候廢棄了這個(gè)flag赦抖，理由是在某些版本的android系統(tǒng)上舱卡，它無法可靠的運(yùn)行，而且對于跨進(jìn)程的并發(fā)修改沒有提供任何機(jī)制來保證队萤。應(yīng)該使用ContentProvider來代替它進(jìn)程多進(jìn)程的數(shù)據(jù)修改轮锥。

坑2:多進(jìn)程反復(fù)讀寫SharedPreferences

描述問題：我在A進(jìn)程中反復(fù)寫入SharedPreferences，在B進(jìn)程中同時(shí)寫入同一個(gè)name的SharedPreferences要尔，導(dǎo)致B進(jìn)程無法寫入舍杜。
官方文檔上描述：對于跨進(jìn)程的并發(fā)修改沒有提供任何機(jī)制來保證份汗。

坑3:亂用SharedPreferences

這個(gè)我就不再這里寫了，網(wǎng)上有大神寫的非常詳細(xì)點(diǎn)擊這里

由于以后要調(diào)整架構(gòu)采用組件化蝴簇，每個(gè)組件需要讀寫一些app的公用信息例如登陸信息等，所以我做了擴(kuò)展SharedProvider中除了基本信息還可以保存對象和集合

sharedProvider.edit().putObject(KEY_6, articleK, ArticleK.class.getName());
sharedProvider.edit().putList(KEY_7, articleKList);
sharedProvider.edit().putMap(KEY_8, kArticleVMap);
sharedProvider.edit().putSet(KEY_9, articleKSet);

綜合以上問題所以決定用ContentProvider來實(shí)現(xiàn)一個(gè)自己的SharedPreferences匆帚。
項(xiàng)目地址點(diǎn)擊這里

Maven

<dependency>
  <groupId>com.andrjhf.sharedprovider</groupId>
  <artifactId>sharedprovider-library</artifactId>
  <version>1.0.2</version>
  <type>pom</type>
</dependency>

Gradle via JCenter

compile 'com.andrjhf.sharedprovider:sharedprovider-library:1.0.2'

編譯版本和最小支持版本

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"
    
    defaultConfig {
        minSdkVersion 9
        targetSdkVersion 22
        ...
    }
}

接入方法：

在AndroidManifest.xml中增加如下方法,標(biāo)準(zhǔn)的provider
android:authorities="com.andrjhf.sharedprovider"不能修改

 <provider
    android:name="com.andrjhf.sharedprovider.PreferencesContentProvider"
    android:authorities="com.andrjhf.sharedprovider"
    android:enabled="true"
    android:exported="false"></provider>

測試方法：

public class MainActivity extends Activity {
        public static final String TAG = "MainActivity";
        public static final String SHARED_NAME = "sharedName1";
        public static final String SHARED_NAME2 = "sharedName2";
        private static final String KEY_1 = "key1";
        private static final String KEY_2 = "key2";
        private static final String KEY_3 = "key3";
        private static final String KEY_4 = "key4";
        private static final String KEY_5 = "key5";
        private static final String KEY_6 = "key6";
        private static final String KEY_7 = "key7";
        private static final String KEY_8 = "key8";
        private static final String KEY_9 = "key9";
        private static final String KEY_10 = "key10";
        private static final String KEY_11 = "key11";
        private static final String KEY_12 = "key12";
        private static final String KEY_13 = "key13";
        private SharedProvider sharedProvider;
        private SharedProvider sharedProvider2;
        private int count = 0;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            List<ArticleK> articleKList = new ArrayList<>();
            Map<ArticleK, ArticleV> kArticleVMap = new HashMap<>();
            Set<ArticleK> articleKSet = new HashSet<>();
            ArticleK articleK = new ArticleK();
            articleK.setTitle("標(biāo)題");
            articleK.setDesc("我是一個(gè)簡介");
            articleK.setImg("http://www.baidu.com/");
            articleK.setUrl("http://www.google.com/");
            articleKList.add(articleK);
            articleK = new ArticleK();
            articleK.setTitle("標(biāo)題11111");
            articleK.setDesc("我是一個(gè)簡介11111");
            articleK.setImg("http://www.baidu.com/11111");
            articleK.setUrl("http://www.google.com/11111");
            articleKList.add(articleK);
            ArticleV articleV = new ArticleV();
            articleK.setTitle("標(biāo)題vvvvv");
            articleK.setDesc("我是一個(gè)簡介vvvvv");
            articleK.setImg("http://www.baidu.com/vvvvv");
            articleK.setUrl("http://www.google.com/vvvvv");
            kArticleVMap.put(articleK, articleV);
            articleKSet.add(articleK);
            sharedProvider = new SharedProviderImpl(getApplicationContext(), SHARED_NAME);
            sharedProvider.edit().putString(KEY_1, "value1");
            sharedProvider.edit().putInt(KEY_2, 100);
            sharedProvider.edit().putLong(KEY_3, 100000000L);
            sharedProvider.edit().putFloat(KEY_4, 66.66F);
            sharedProvider.edit().putBoolean(KEY_5, false);
            sharedProvider.edit().putObject(KEY_6, articleK, ArticleK.class.getName());
            sharedProvider.edit().putList(KEY_7, articleKList);
            sharedProvider.edit().putMap(KEY_8, kArticleVMap);
            sharedProvider.edit().putSet(KEY_9, articleKSet);
            sharedProvider.edit().putString(KEY_10, "value10");
            sharedProvider.edit().remove(KEY_10);
    //        sharedProvider.edit().clear();
            sharedProvider2 = new SharedProviderImpl(getApplicationContext(), SHARED_NAME2);
            sharedProvider2.edit().putString(KEY_1, "value1");
            sharedProvider2.edit().putInt(KEY_2, 100);
            sharedProvider2.edit().putLong(KEY_3, 100000000L);
            sharedProvider2.edit().putFloat(KEY_4, 66.66F);
            sharedProvider2.edit().putBoolean(KEY_5, true);
            sharedProvider2.edit().putObject(KEY_6, articleK, ArticleK.class.getName());
            sharedProvider2.edit().putList(KEY_7, articleKList);
            sharedProvider2.edit().putMap(KEY_8, kArticleVMap);
            sharedProvider2.edit().putSet(KEY_9, articleKSet);
            sharedProvider2.edit().putString(KEY_10, "value10");
            Log.e(TAG, KEY_1 + " : " + sharedProvider2.getString(KEY_1, "default_key_1"));
            Log.e(TAG, KEY_2 + " : " + sharedProvider2.getInt(KEY_2, -100));
            Log.e(TAG, KEY_3 + " : " + sharedProvider2.getLong(KEY_3, -1000L));
            Log.e(TAG, KEY_4 + " : " + sharedProvider2.getFloat(KEY_4, -55.55F));
            Log.e(TAG, KEY_5 + " : " + sharedProvider2.getBoolean(KEY_5, false));
            Log.e(TAG, KEY_6 + " : " + sharedProvider2.getObject(KEY_6, ArticleK.class.getName()));
            Log.e(TAG, KEY_7 + " : " + sharedProvider2.getList(KEY_7));
            Log.e(TAG, KEY_8 + " : " + sharedProvider2.getMap(KEY_8));
            Log.e(TAG, KEY_9 + " : " + sharedProvider2.getSet(KEY_9));
            Log.e(TAG, KEY_10 + " : " + sharedProvider2.getString(KEY_10, "default10"));
            Log.e(TAG, "ALL" + " : " + sharedProvider2.getAll());
            //如果獲取類型錯(cuò)誤會(huì)返回默認(rèn)值熬词，沒有類型轉(zhuǎn)換
            Log.e(TAG, "Default " + KEY_2 + " : " + sharedProvider2.getLong(KEY_2, -1000L));
            Log.e(TAG, "Default " + KEY_3 + " : " + sharedProvider2.getInt(KEY_3, -100));
            sharedProvider2.contains(KEY_1);
    //        Intent intent = new Intent(MainActivity.this, MyService.class);
    //        startService(intent);
    //        new Thread(new Runnable() {
    //            @Override
    //            public void run() {
    //                while (true) {
    //                    try {
    //                        TimeUnit.MILLISECONDS.sleep(500);
    //                    } catch (InterruptedException e) {
    //                        e.printStackTrace();
    //                    }
    //                    int keyInt7 = sharedProvider.getInt(KEY_7, -1);
    //                    Log.e(TAG, KEY_7 + " : " + keyInt7);
    ////                    sharedProvider.edit().putInt(KEY_7, count++);
    //                }
    //            }
    //        }).start();
            new Thread(new Runnable() {
                @Override
                public void run() {
                    String string = getFromAssets("test.txt");
                    SharedPreferences sharedPreferences = getSharedPreferences("app", Context.MODE_PRIVATE);
                    long start = System.currentTimeMillis();
    //                sharedPreferences.edit().putString(string, "value").commit();
    //                Log.e(TAG, "set preferences end - start = " + (System.currentTimeMillis() - start));
    //
    //                start = System.currentTimeMillis();
    //                sharedProvider2.edit().putString(string, "value");
    //                Log.e(TAG, "set provider end - start = " + (System.currentTimeMillis() - start));
                    start = System.currentTimeMillis();
                    sharedPreferences.edit().putString("key", "1111111111111111111111111111111").commit();
                    Log.e(TAG, "set preferences end - start = " + (System.currentTimeMillis() - start));
                    start = System.currentTimeMillis();
                    sharedProvider2.edit().putString("key", "1111111111111111111111111111111");
                    Log.e(TAG, "set provider end - start = " + (System.currentTimeMillis() - start));
    //                start = System.currentTimeMillis();
    //                String valuepre = sharedPreferences.getString("key", "");
    //                Log.e(TAG, "get preferences end - start = " + (System.currentTimeMillis() - start));
    //
    //                start = System.currentTimeMillis();
    //                valuepre = sharedProvider2.getString("key", "");
    //                Log.e(TAG, "get provider end - start = " + (System.currentTimeMillis() - start));
                }
            }).start();
        }
        public void onClick(View view) {
            sharedProvider.edit().putString(KEY_8, "sdfsdfsdfsdf");
            Toast.makeText(this, KEY_8, Toast.LENGTH_SHORT).show();
        }
        public String getFromAssets(String fileName) {
            try {
                InputStreamReader inputReader = new InputStreamReader(getResources().getAssets().open(fileName));
                BufferedReader bufReader = new BufferedReader(inputReader);
                String line = "";
                String Result = "";
                while ((line = bufReader.readLine()) != null)
                    Result += line;
                return Result;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    }

缺陷：

ContentProvider多進(jìn)程訪問的時(shí)候有時(shí)會(huì)導(dǎo)致Client端進(jìn)程被kill。
感謝@Shawn_Dut提出的問題吸重。
例子：Service進(jìn)程在寫數(shù)據(jù)互拾，Client進(jìn)程在讀取數(shù)據(jù)，如果Service進(jìn)程由于各種原因掛掉了嚎幸，Client進(jìn)程有可能被kill颜矿，這個(gè)問題無法規(guī)避。
具體原因請點(diǎn)擊這里QQ音樂技術(shù)團(tuán)隊(duì)的帖子嫉晶。