将SQLlite数据库备份/还原到Google云端硬盘应用文件夹

Question

我正在尝试将功能合并到备份和恢复应用程序数据库到谷歌驱动器应用程序文件夹(用户不可见).我浏览了为android 提供的基本设置指南设置指南,可以让用户授权应用程序并到达调用onConnected方法的位置.

我面临的问题是,我不知道如何将数据库文件(.db)从设备"发送"到google drive app文件夹.Google已经共享了用于创建新文件的代码段,但就此而言.我确实发现了一个前面提到的问题,模糊地类似于我正在寻找的Google驱动器备份和恢复Android应用程序的数据库和共享首选项,但后来又不是我想要的.

搜索谷歌不会返回任何有用的链接,因为这是相对较新的API.

更新1:

共享onConnected()代码,

    public void onConnected(Bundle bundle) {
    Toast.makeText(GoogleSignIn.this, "In onConnected activity", Toast.LENGTH_SHORT).show();

    // Testing to see if database is indeed uploaded to google drive app folder
    String db_name = "XXX_DB";
    String currentDBPath = "/data/" + "com.abc.efg" + "/databases/" + db_name;
    saveToDrive(
            Drive.DriveApi.getAppFolder(mGoogleApiClientDrive),
            "XXX_DB.db",
            "application/x-sqlite3",
            new java.io.File(currentDBPath)
    );
}

更新2:

下面分享的解决方案非常适合将数据库上传到google drive app文件夹.对于那些可能面临类似问题的人,请尝试将数据库路径更改为"/data/data/com.abc.efg/databases/" + db_name而不是"/data/com.abc.efg/databases/" + db_name

下一步是能够从google drive app文件夹中检索和恢复数据库.如果我能够使它工作,应该更新这个问题.

Answer 1

假设你有一个MyDbFile.db文件的路径,你可以使用这样的结构:

 ... 
 saveToDrive(
   Drive.DriveApi.getAppFolder(getGoogleApiClient()),
   "MyDbFile.db", 
   "application/x-sqlite3",
   new java.io.File("\...\...\...\MyDbFile.db")
 );
 ...

DriveId mDriveId;
/******************************************************************
 * create file in GOODrive
 * @param pFldr parent's ID
 * @param titl  file name
 * @param mime  file mime type  (application/x-sqlite3)
 * @param file  file (with content) to create
 */
void saveToDrive(final DriveFolder pFldr, final String titl,
                 final String mime, final java.io.File file) {
  if (getGoogleApiClient() != null && pFldr != null && titl != null && mime != null && file != null) try {
    // create content from file
    Drive.DriveApi.newDriveContents(getGoogleApiClient()).setResultCallback(new ResultCallback<DriveContentsResult>() {
      @Override
      public void onResult(DriveContentsResult driveContentsResult) {
        DriveContents cont = driveContentsResult != null && driveContentsResult.getStatus().isSuccess() ?
          driveContentsResult.getDriveContents() : null;

        // write file to content, chunk by chunk
        if (cont != null) try {
          OutputStream oos = cont.getOutputStream();
          if (oos != null) try {
            InputStream is = new FileInputStream(file);
            byte[] buf = new byte[4096];
            int c;
            while ((c = is.read(buf, 0, buf.length)) > 0) {
              oos.write(buf, 0, c);
              oos.flush();
            }
          }
          finally { oos.close();}

          // content's COOL, create metadata
          MetadataChangeSet meta = new Builder().setTitle(titl).setMimeType(mime).build();

          // now create file on GooDrive
          pFldr.createFile(getGoogleApiClient(), meta, cont).setResultCallback(new ResultCallback<DriveFileResult>() {
            @Override
            public void onResult(DriveFileResult driveFileResult) {
              if (driveFileResult != null && driveFileResult.getStatus().isSuccess()) {
                DriveFile dFil = driveFileResult != null && driveFileResult.getStatus().isSuccess() ?
                  driveFileResult.getDriveFile() : null;
                if (dFil != null) {
                  // BINGO , file uploaded
                  dFil.getMetadata(getGoogleApiClient()).setResultCallback(new ResultCallback<MetadataResult>() {
                    @Override
                    public void onResult(MetadataResult metadataResult) {
                      if (metadataResult != null && metadataResult.getStatus().isSuccess()) {
                        DriveId mDriveId = metadataResult.getMetadata().getDriveId();
                      }
                    }
                  });
                }
              } else { /* report error */     }
            }
          });
        } catch (Exception e) { e.printStackTrace(); }
      }
    });
  } catch (Exception e) { e.printStackTrace(); }
}

/*******************************************************************
 * get file contents
 */
void readFromGooDrive() {
  byte[] buf = null;
  if (getGoogleApiClient() != null && getGoogleApiClient().isConnected()) try {
    DriveFile df = Drive.DriveApi.getFile(getGoogleApiClient(), mDriveId);
    df.open(getGoogleApiClient(), DriveFile.MODE_READ_ONLY, null)
      .setResultCallback(new ResultCallback<DriveContentsResult>() {
      @Override
      public void onResult(DriveContentsResult driveContentsResult) {
        if ((driveContentsResult != null) && driveContentsResult.getStatus().isSuccess()) {
          DriveContents cont = driveContentsResult.getDriveContents();
          // DUMP cont.getInputStream() to your DB file
          cont.discard(getGoogleApiClient());    // or cont.commit();  they are equiv if READONLY
        }
      }
    });
  } catch (Exception e) { e.printStackTrace(); }
}

祝好运