Question

我正在尝试将备份和恢复应用数据库的功能合并到google drive app文件夹（对用户不可见）。我浏览了为android提供的基本设置指南setup guide，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。我确实发现了一个先前问过的问题，与我正在寻找的Google drive to back up and restore database and shared preferences of Android application模糊地相似，但后来又找不到我要找的东西。

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。对于可能遇到类似问题的用户，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。如果我能够让它工作，请更新这个问题。

Answer 1

假设您有 MyDbFile.db 文件的路径，您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(); }
}

祝你好运

将SQLlite数据库备份/还原到Google云端硬盘应用文件夹

1 个答案: