（蚂蚁金服mPaaS）统一存储

1. 数据库存储 ：基于 OrmLite 架构，提供了数据库底层加密能力。
2. 键值对存储 ：基于 Android 原生的 SharedPreferences，同时进行了一定的包装，提升了易用性。
3. 文件存储 ：基于 Android 原生 File，提供了文件加密能力。

二：存储方案

1. 数据库存储方案

(1) 架构

基于 OrmLite 架构，参考： 【Android - 框架】之ORMLite的使用

(2) 安全性

在数据库创建或者打开的时候，传入passwordSQLite加密方式

public SQLiteOpenHelper(Context context, String name, CursorFactory factory, int version, DatabaseErrorHandler errorHandler) {
        this.mPassword = null;
        ...
    }


    public SQLiteDatabase getWritableDatabase() {
        synchronized(this) {
            return this.getDatabaseLocked(true);
        }
    }

    public SQLiteDatabase getReadableDatabase() {
        synchronized(this) {
            return this.getDatabaseLocked(false);
        }
    }
    
    private SQLiteDatabase getDatabaseLocked(boolean writable) {
        ...

                        db = SQLiteDatabase.openOrCreateDatabase(dbFile.getAbsolutePath(), this.mFactory, this.mErrorHandler, this.mEnableWriteAheadLogging, this.mPassword);
                    } catch (SQLiteException var14) {
                        if(writable) {
                            throw var14;
                        }
        ...
    }
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最终调SQLiteConnection.java

private void open() {
        this.mConnectionPtr = nativeOpen(this.mConfiguration.path, this.mConfiguration.openFlags, this.mConfiguration.label, false, false);
        this.setEncryptKey();
        this.setForeignKeyModeFromConfiguration();
        this.setWalModeFromConfiguration();
        this.setJournalSizeLimit();
        this.setAutoCheckpointInterval();
        this.setLocaleFromConfiguration();
        int functionCount = this.mConfiguration.customFunctions.size();

        for(int i = 0; i < functionCount; ++i) {
            SQLiteCustomFunction function = (SQLiteCustomFunction)this.mConfiguration.customFunctions.get(i);
            nativeRegisterCustomFunction(this.mConnectionPtr, function);
        }

    }
    
    private void setEncryptKey() {
        if(!this.mConfiguration.isInMemoryDb() && !this.mIsReadOnlyConnection) {
            String password = this.mConfiguration.password;
            if(password != null) {
                File encryptFile = new File(this.mConfiguration.path + "-encrypt");
                if(encryptFile.exists()) {
                    this.execute("PRAGMA key='" + password + "';", (Object[])null, (Object)null);
                } else {
                    this.execute("PRAGMA rekey='" + password + "';", (Object[])null, (Object)null);

                    try {
                        encryptFile.createNewFile();
                    } catch (IOException var4) {
                        Log.e("SQLiteConnection", "Can't touch " + encryptFile.getName() + ", can't rekey the database");
                    }
                }
            }
        }

    }
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(3) 使用便捷性

• 不用写 sql 语句，创建数据库继承OrmLiteSqliteOpenHelper，建表通过JavaBean和注解的方式。增删改查使用Dao的方式。
• 数据库加密，在创建时传入password即可。

2. 键值对存储方案

(1) 架构

封装类APSharedPreferences.java

private Context sContext = null;
    private String mGroup = "alipay_default_sp";  // 组id，与文件名类似
    private SharedPreferences mSP;
    private int mMode = 0;
    private Editor edit = null;

    public boolean getBoolean(String key, boolean defValue) {
        return this.getBoolean(this.getGroup(), key, defValue);
    }

    public String getString(String key, String defValue) {
        return this.getString(this.getGroup(), key, defValue);
    }
    ...
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管理类SharedPreferencesManager.java

private static LruCache<String, APSharedPreferences> spList = new LruCache(30); // 定义了一个最大长度为30的缓存列表，使用lru算法
    
    public SharedPreferencesManager() {
    }

    public static APSharedPreferences getInstance(Context context, String groupId) {
        return getInstance(context, groupId, 0);
    }

    public static APSharedPreferences getInstance(Context context, String groupId, int mode) {
        if(context != null && !TextUtils.isEmpty(groupId)) {
            APSharedPreferences sp = (APSharedPreferences)spList.get(groupId);
            if(sp == null) {
                Class var4 = SharedPreferencesManager.class;
                synchronized(SharedPreferencesManager.class) {
                    sp = (APSharedPreferences)spList.get(groupId);
                    if(sp == null) {
                        sp = new APSharedPreferences(context, groupId, mode);
                        spList.put(groupId, sp);
                    }
                }
            }

            return sp;
        } else {
            return null;
        }
    }
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(2) 加密

无

(3) 使用便捷性

• 对SharedPreferences api做了封装，更方便使用
• 对文件分组，便于管理，增加了增删改操作。
• 使用LruCache，加快读写速度。

3. 文件存储方案

(1) 架构

• ZFile：该文件类型存储在 data/data/package_name/files 下。
• ZExternalFile：该文件类型存储在 sdcard/Android/data/package_name/files 下。
• ZFileInputStream/ZFileOutputStream：文件存储输入输出流，使用该流则不进行加解密。
• ZSecurityFileInputStream/ZSecurityFileOutputStream：文件存储安全输入输出流，使用该流则会

ZFile.java

public class ZFile extends BaseFile {
    private static final long serialVersionUID = -1952946196402763362L;
    // groupId为目录，name为文件名，subPath为相对子路径
    public ZFile(Context context, String groupId, String name, String subPath) {
        super(buildPath(context, groupId, name, subPath));
    }

    public ZFile(Context context, String groupId, String name) {
        super(buildPath(context, groupId, name, (String)null));
    }

    private static String buildPath(Context context, String groupId, String name, String subPath) {
                ...
                String path = "";
                // 拼文件路径
                String dir = context.getFilesDir() + File.separator + groupId + formatPath(subPath);
                File fileDir = new File(dir);
                if(!fileDir.exists()) {
                    fileDir.mkdirs();
                }
                path = dir + name;
                return path;
                ...
    }
}
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ZExternalFile.java

public class ZExternalFile extends BaseFile {
    private static final String Tag = "ZExternalFile";
    protected static final String ExtDataTunnel = "ExtDataTunnel";
    private static final long serialVersionUID = -3489082633723468737L;

    public ZExternalFile(Context context, String groupId, String name, String subPath) {
        super(buildPath(context, groupId, name, subPath));
    }

    public ZExternalFile(Context context, String groupId, String name) {
        super(buildPath(context, groupId, name, (String)null));
    }

    private static String buildPath(Context context, String groupId, String name, String subPath) {
            ...
            File externalFilesDir = null;

            try {
                externalFilesDir = context.getExternalFilesDir(groupId);
            } catch (Throwable var8) {
                Log.w("ZExternalFile", "context.getExternalFilesDir(" + groupId + ") failed!", var8);
            }

            String path;
            String dir;
            if(externalFilesDir == null) {
                Log.w("ZExternalFile", "externalFilesDir is null");
                path = FileUtils.getSDPath();
                if(TextUtils.isEmpty(path)) {
                    return "";
                }

                dir = path + File.separator + "ExtDataTunnel" + File.separator + "files" + File.separator + groupId;
                externalFilesDir = new File(dir);
            }

            path = "";
            dir = externalFilesDir.getAbsolutePath() + formatPath(subPath);
            File fileDir = new File(dir);
            if(!fileDir.isDirectory() || !fileDir.exists()) {
                fileDir.mkdirs();
            }

            path = dir + name;
            return path;
            ...
    }
}
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ZSecurityFileOutputStream.java

public class ZSecurityFileOutputStream extends ZFileOutputStream {
    
    public void write(byte[] buffer) throws IOException {
        this.byteList.add(buffer);
        this.byteSize += buffer.length;
    }
    
    public void write(byte[] buffer, int byteOffset, int byteCount) throws IOException {
        int size = byteCount;
        if(byteCount > buffer.length) {
            size = buffer.length;
        }

        byte[] sBuffer = new byte[size];
        System.arraycopy(buffer, byteOffset, sBuffer, 0, size);
        this.byteList.add(sBuffer);
        this.byteSize += size;
    }
    
    // 在close的时候，才将数据加密并且写入文件
    public void close() throws IOException {
        byte[] finalByte = new byte[this.byteSize];
        int pos = 0;
        if(this.byteList != null && !this.byteList.isEmpty()) {
            for(int i = 0; i < this.byteList.size(); ++i) {
                byte[] item = (byte[])this.byteList.get(i);
                if(this.byteSize >= pos + item.length) {
                    System.arraycopy(item, 0, finalByte, pos, item.length);
                }

                pos += item.length;
            }

            this.byteList.clear();
            Object var6 = null;

            byte[] enByte;
            try {
                // 加密
                enByte = TaobaoSecurityEncryptor.encrypt(this.mContext, finalByte);
            } catch (Exception var5) {
                throw new IOException(var5);
            }

            super.write(enByte, 0, enByte.length);
            super.close();
        }
    }
}
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ZSecurityFileInputStream.java

private void initBuffer() throws IOException {
        int size = super.available();
        byte[] enBuffer = new byte[size];
        super.read(enBuffer, 0, enBuffer.length);
        super.close();

        try {
            // 解密
            this.mBuffer = TaobaoSecurityEncryptor.decrypt(this.mContext, enBuffer);
        } catch (Exception var4) {
            LoggerFactory.getTraceLogger().warn("ZSecurityFileInputStream", var4);
            throw new IOException();
        }
    }
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