Using Dropbox API to upload a file with Android

问题:

How can I upload a File (graphic, audio and video file) with Android using the Dropbox API to Dropbox? I followed the tutorial on the Dropbox SDK Android page and could get the sample to work. But now instead of a String I want to upload an actual File object and am struggling.

The sample code works without any problems and looks like this:

    String fileContents = "Hello World!";
ByteArrayInputStream inputStream = new ByteArrayInputStream(fileContents.getBytes());
try {
    Entry newEntry = mDBApi.putFile("/testing_123456.txt", inputStream, fileContents.length(), null, null);
} catch (DropboxUnlinkedException e) {
    Log.e("DbExampleLog", "User has unlinked.");
} catch (DropboxException e) {
    Log.e("DbExampleLog", "Something went wrong while uploading.");
}   

But when I try to change it and upload an actual file with this code:

    File tmpFile = new File(fullPath, "IMG_2012-03-12_10-22-09_thumb.jpg");

// convert File to byte[]
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(tmpFile);
bos.close();
oos.close();
byte[] bytes = bos.toByteArray();

ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes);
try {
    Entry newEntry = mDBApi.putFile("/IMG_2012-03-12_10-22-09_thumb.jpg", inputStream, tmpFile.length(), null, null);
} catch (DropboxUnlinkedException e) {
    Log.e("DbExampleLog", "User has unlinked.");
} catch (DropboxException e) {
    Log.e("DbExampleLog", "Something went wrong while uploading.");
}

I have no success getting a DropboxException error. I think something where I try to convert the File object to the byte-stream must be wrong but this is just an assumption.

Other than the String example there is nothing else documented on the Dropbox page for Android.

Thanks for any help.

回答1:

I found the solution - if anyone is interested here is the working code:

private DropboxAPI<AndroidAuthSession> mDBApi;//global variable

File tmpFile = new File(fullPath, "IMG_2012-03-12_10-22-09_thumb.jpg");

FileInputStream fis = new FileInputStream(tmpFile);

            try {
                DropboxAPI.Entry newEntry = mDBApi.putFileOverwrite("IMG_2012-03-12_10-22-09_thumb.jpg", fis, tmpFile.length(), null);
            } catch (DropboxUnlinkedException e) {
                Log.e("DbExampleLog", "User has unlinked.");
            } catch (DropboxException e) {
                Log.e("DbExampleLog", "Something went wrong while uploading.");
            }

回答2:

Here is another implementation of Dropbox API to upload and download a file. This can be implemented for any type of file.

String file_name = "/my_file.txt";
String file_path = Environment.getExternalStorageDirectory()
        .getAbsolutePath() + file_name;
AndroidAuthSession session;

public void initDropBox() {

    AppKeyPair appKeys = new AppKeyPair(APP_KEY, APP_SECRET);
    session = new AndroidAuthSession(appKeys);
    mDBApi = new DropboxAPI<AndroidAuthSession>(session);
    mDBApi.getSession().startOAuth2Authentication(MyActivity.this);

}

Entry response;

public void uploadFile() {
    writeFileContent(file_path);
    File file = new File(file_path);
    FileInputStream inputStream = null;
    try {
        inputStream = new FileInputStream(file);
    } catch (FileNotFoundException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }


    try {
        response = mDBApi.putFile("/my_file.txt", inputStream,
                file.length(), null, null);
        Log.i("DbExampleLog", "The uploaded file's rev is: " + response.rev);
    } catch (DropboxException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();

    }

}
public void downloadFile() {

    File file = new File(file_path);
    FileOutputStream outputStream = null;

    try {
        outputStream = new FileOutputStream(file);
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    DropboxFileInfo info = null;
    try {
        info = mDBApi.getFile("/my_file.txt", null, outputStream, null);



        Log.i("DbExampleLog", "The file's rev is: "
                + info.getMetadata().rev);
    } catch (DropboxException e) {
        // TODO Auto-generated catch block

        e.printStackTrace();
    }

}

@Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        if (mDBApi.getSession().authenticationSuccessful()) {
            try {
                // Required to complete auth, sets the access token on the
                // session

            mDBApi.getSession().finishAuthentication();

            String accessToken = mDBApi.getSession().getOAuth2AccessToken();

            /**
             * You'll need this token again after your app closes, so it's
             * important to save it for future access (though it's not shown
             * here). If you don't, the user will have to re-authenticate
             * every time they use your app. A common way to implement
             * storing keys is through Android's SharedPreferences API.
             */

        } catch (IllegalStateException e) {
            Log.i("DbAuthLog", "Error authenticating", e);
        }
    }
}

->Call uploadFile() and downLoadFile() method in child thread otherwise it will give you exception

->For that use AsyncTask and call these above method in doInBackground method.

Hope this will be helpful...Thanks

回答3:

@e-nature's answer is more than correct...just thought I'd point everyone to Dropbox's official site that shows how to upload a file and much more.

Also, @e-nature's answer overwrites files with the same name, so if you don't want that behaviour simply use .putFile instead of .putFileOverwrite. .putFile has an extra argument, you can simply add null to to the end. More info.

回答4:

Here is another example which uses the Dropbox v2 API but a 3rd party SDK. It works exactly the same for Google Drive, OneDrive and Box.com by the way.

// CloudStorage cs = new Box(context, "[clientIdentifier]", "[clientSecret]");
// CloudStorage cs = new OneDrive(context, "[clientIdentifier]", "[clientSecret]");
// CloudStorage cs = new GoogleDrive(context, "[clientIdentifier]", "[clientSecret]");
CloudStorage cs = new Dropbox(context, "[clientIdentifier]", "[clientSecret]");
new Thread() {
    @Override
    public void run() {
        cs.createFolder("/TestFolder"); // <---
        InputStream stream = null;
        try {
            AssetManager assetManager = getAssets();
            stream = assetManager.open("UserData.csv");
            long size = assetManager.openFd("UserData.csv").getLength();
            cs.upload("/TestFolder/Data.csv", stream, size, false); // <---
        } catch (Exception e) {
            // TODO: handle error
        } finally {
            // TODO: close stream
        }
    }
}.start();

It uses the CloudRail Android SDK