android SharedPreferences在mysql中保存和恢复数据

Question

我尝试在mysql中保存SharedPreferences并恢复它。我使用以下代码存储SharedPreferences：

 private boolean saveSharedPreferencesToFile(File dst) {
        boolean res = false;
        ObjectOutputStream output = null;
        try {
            output = new ObjectOutputStream(new FileOutputStream(dst));
            SharedPreferences pref = getSharedPreferences("AnimeSAShardPref", MODE_PRIVATE);
            output.writeObject(pref.getAll());
            res = true;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if (output != null) {
                    output.flush();
                    output.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return res;
    }

创建文件后，我读取文件并将其上传到mysql，没关系。但是当我想从mysql中获取数据以使其成为文件时我可以使用：

 @SuppressWarnings({ "unchecked" })
    private boolean loadSharedPreferencesFromFile(File src) {
        boolean res = false;
        ObjectInputStream input = null;
        try {
            input = new ObjectInputStream(new FileInputStream(src));
            SharedPreferences.Editor prefEdit = getSharedPreferences("sssss", MODE_PRIVATE).edit();
            prefEdit.clear();
            Map<String, ?> entries = (Map<String, ?>) input.readObject();
            for (Map.Entry<String, ?> entry : entries.entrySet()) {
                Object v = entry.getValue();
                String key = entry.getKey();

                if (v instanceof Boolean)
                    prefEdit.putBoolean(key, ((Boolean) v));
                else if (v instanceof Float)
                    prefEdit.putFloat(key, ((Float) v));
                else if (v instanceof Integer)
                    prefEdit.putInt(key, ((Integer) v));
                else if (v instanceof Long)
                    prefEdit.putLong(key, ((Long) v));
                else if (v instanceof String)
                    prefEdit.putString(key, ((String) v));
            }
            prefEdit.apply();
            res = true;
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                if (input != null) {
                    input.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return res;
    }

我收到此错误：

    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ java.io.StreamCorruptedException
    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:2067)
    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ at java.io.ObjectInputStream.<init>(ObjectInputStream.java:372)
    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ at com.test.LoginActivity.loadSharedPreferencesFromFile(LoginActivity.java:347)
    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ at com.test.LoginActivity.access$300(LoginActivity.java:57)
    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ at com.test.LoginActivity$DownloadFileFromURL.onPostExecute(LoginActivity.java:337)
    04-30 10:45:00.910  24101-24101/com.test W/System.err﹕ at com.test.LoginActivity$DownloadFileFromURL.onPostExecute(LoginActivity.java:303)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at android.os.AsyncTask.finish(AsyncTask.java:632)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at android.os.AsyncTask.access$600(AsyncTask.java:177)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:102)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at android.os.Looper.loop(Looper.java:146)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5593)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:515)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
    04-30 10:45:00.920  24101-24101/com.test W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)