Develop Reference

AWS Download function issue with file path

I have implemented a function to download aws s3 files using the following code:
public void credentialsProvider()
{
CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
getApplicationContext(), "us-east-2:xxxxxx-xxxxx-xxxxx-xxxx-xxxxxxx", Regions.US_EAST_2
);
setAmazonS3Client(credentialsProvider);
System.out.println("setAmazonS3Client done");
}
public void setAmazonS3Client( CognitoCachingCredentialsProvider credentialsProvider)
{
s3 = new AmazonS3Client(credentialsProvider);
s3.setRegion(Region.getRegion(Regions.US_EAST_2));
}
public void setTransferUtility()
{
transferUtility = new TransferUtility(s3, getApplicationContext());
System.out.println("setTransferUtility done");
}
public void setFileDownload()
{
final String path = this.getFilesDir().getAbsolutePath();
File myFile = new File(path);
TransferObserver transferObserver = transferUtility.download("sample-bucket-001", "images-4.jpeg", myFile);
transferObserverListener(transferObserver);
}
public void transferObserverListener(TransferObserver transferObserver)
{
transferObserver.setTransferListener(new TransferListener() {
#Override
public void onStateChanged(int id, TransferState state) {
System.out.println("onStateChanged: "+ state);
if(state == TransferState.FAILED || state == TransferState.WAITING_FOR_NETWORK){
}
}
#Override
public void onProgressChanged(int id, long bytesCurrent, long bytesTotal) {
int percentage = (int)(bytesCurrent/bytesTotal * 100);
System.out.println("percentage: "+ percentage);
}
#Override
public void onError(int id, Exception ex) {
System.out.println("Error faced: "+ ex.toString());
}
});
}
As I try to execute the following code I get the following error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xxxxxx.xxxxxxxx/com.xxxxxx.xxxxxxxx.Activity}: java.lang.IllegalArgumentException: Invalid file: /data/user/0/com.xxxxxx.xxxxxxxx/files/
I cannot save the file on external storage as I prefer to have them hidden and protected, and deleted in case the app got deleted. I used to use the path to save files on it, that are directly loaded from the internet and no problem there.
Kindly advise on the matter.

The file path supplied to TransferUtility needs to include a file name, e.g.:
final String path = this.getFilesDir().getAbsolutePath() + "images-4.jpeg";

I have finally found the solution to the question asked, which simple using a path that is totally new, unused previously, so it can create the folder that where it will store the downloaded picture or file.
final String path = this.getFilesDir().getAbsolutePath()+"/zip";
I wish Amazon's feedback could be a bit more specific than just 'invalid file'.

Validate multiple URLS and get which ones are working

I'm using this library to validate URL within my app but I wanna run the same method for 4 or more URLs instead of one but can't seem to figure out how to.
My code:
validateUrl(this, "https://www.dummy.dummy/");
SharedPreferences sharedPreferences = getSharedPreferences("url", MODE_PRIVATE);
if (sharedPreferences.getBoolean("validated", true)) {
Log.e("WEB", "RUNNING");
doSomething():
} else {
Log.e("WEB", "DOWN");
}
private void validateUrl (Context context, String URL) {
new FarlaGetRequest(context)
.setURL(URL)
.setListener(new FarlaGetRequest.onGetRequestListener() {
#Override
public void onSuccess(String response) {
Log.e("WEB", "Done");
SharedPreferences.Editor editor = getSharedPreferences("url", MODE_PRIVATE).edit();
editor.putBoolean("validated",true);
editor.apply();
}
#Override
public void onFailure(int error) {
Log.e("WEB", "Failed");
}
}).execute();
}
The goal is, if the url is able to connect (server sent response 200) then do something, else don't.
So what I'm stuck at is, how do I do this for multiple URLs?
Example:
Check 1st (log if it's running or down)
Check 2nd (log if its running or down)
Same for the 3rd and 4th as well.
At the end, it should say which are active and which ones aren't so can someone help me please? ease?

you can use a List of url's and execute that validator function for the number of times that the size of list is and if the url connects (got response 200) then just move to the next url otherwise remove that url from list. So , in this way you will end up with all the working URL's.
Solution Code:
List<String> urlList = new ArrayList<>();
// add all url's in the list; for example : urlList.add("https://www.dummy.dummy/");
Now we will use a loop to execute the checker function for all the url's
for(int i =0; i<urlList.size();i++)
{
validateUrl (context, urlList.get(i))();
}
and in the YOUR_URL_CHECKER_FUNCTION just put a condition that if the server sents response as 200 then do nothing otherwise urlList .remove("https://www.dummy.dummy/")
Sample code:
private void validateUrl (Context context, String URL) {
new FarlaGetRequest(context)
.setURL(URL)
.setListener(new FarlaGetRequest.onGetRequestListener() {
#Override
public void onSuccess(String response) {
// HERE YOU CAN CHECK THAT WHAT'S THE RESPONSE**
if(!response.equals("200"))
{
`urlList .remove("https://www.dummy.dummy/")`// link to remove
}
}
#Override
public void onFailure(int error) {
Log.e("WEB", "Failed");
}
}).execute();
}
Hope you get that. Feel free to ask if something is unclear. And kindly mark it as the correct answer if it helps you so that this answer can help any other needy.😀

FFmpeg - cannot find ExecuteBinaryResponseHandler - Android/Java

I am trying to make a module for react-native that will change a video into a gif. I have little to no experience with android studios/java, but I would love to learn more! I am using this library to convert the video to a gif. Here is my code:
package com.reactlibrary;
import android.widget.Toast;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactMethod;
import com.github.hiteshsondhi88.libffmpeg.FFmpeg;
public class RNGifMakerModule extends ReactContextBaseJavaModule {
private final ReactApplicationContext reactContext;
public RNGifMakerModule(ReactApplicationContext reactContext) {
super(reactContext);
this.reactContext = reactContext;
}
#Override
public String getName() {
return "RNGifMakerModule";
}
#ReactMethod
public void alert(String message) {
Toast.makeText(getReactApplicationContext(), "Error", Toast.LENGTH_LONG).show();
String[] cmd = {"-i"
, message
, "Image.gif"};
conversion(cmd);
}
public void conversion(String[] cmd) {
FFmpeg ffmpeg = FFmpeg.getInstance(this.reactContext);
try {
// to execute "ffmpeg -version" command you just need to pass "-version"
ffmpeg.execute(cmd, new ExecuteBinaryResponseHandler() {
#Override
public void onStart() {
}
#Override
public void onProgress(String message) {
}
#Override
public void onFailure(String message) {
}
#Override
public void onSuccess(String message) {
}
#Override
public void onFinish() {
}
});
} catch (FFmpegCommandAlreadyRunningException e) {
// Handle if FFmpeg is already running
e.printStackTrace();
}
}
}
And I get this error:
Error:(43, 31) error: cannot find symbol class ExecuteBinaryResponseHandler
This seems odd to be, because in the documentation for ffmpeg-android-java it says to use almost exactly the same code.
Bounty
The bounty will be awarded to you if you can find a way to convert a video.mp4 into a gif. You do not necessarily have to use FFmpeg, but your solution has to work with java/android studios.

First of all you should init ffmpeg correctly.
FFmpeg ffmpeg = FFmpeg.getInstance(this.reactContext);
// please add following method after
ffmpeg.loadBinary(new FFmpegLoadBinaryResponseHandler() {
#Override
public void onFailure() {
// probably your device not supported
}
#Override
public void onSuccess() {
// you should init flag here (isLoaded, isReady etc.)
}
Only after onSuccess() you can work with commands.
Then please check following answer by LordNeckbeard.
So your code should be something like this:
if (isFFmpegLoaded) {
// ffmpeg.execute(commands from link from the answer)
}
Please do not forget to remove all spaces from command's string and "ffmpeg" word.
To keep command more readable I will recommend to build command like this:
final String[] command = new String[11]; // example of the first command in the answer
command[0] = "-y";
command[1] = "-ss";
command[2] = "30";
command[3] = "-t";
command[4] = "3";
command[5] = "-i";
command[6] = "-t";
command[7] = "filePath";
command[8] = "-vf";
command[9] = "fps=10,scale=320:-1:flags=lanczos,palettegen";
command[10] = "palette.png";
Please make sure that you have storage permission to work with file just in case you are working on external storage.
Based on this strategy ffmpeg works well for me. Thanks and good luck!

First of all, you should use: File - Invalidate Caches/Restart - Invalidate and Restart and try to reimport ExecuteBinaryResponseHan‌dler. If the problem hasn't been resolved you can try the small hack. Inside your project create package com.github.hiteshsondhi88.libffmpeg and class:
public class ExecuteBinaryResponseHandler implements FFmpegExecuteResponseHandler {
#Override
public void onSuccess(String message) {
}
#Override
public void onProgress(String message) {
}
#Override
public void onFailure(String message) {
}
#Override
public void onStart() {
}
#Override
public void onFinish() {
}
}
It should be as on image:
Then inside your build.gradle file in defaultConfig block add multiDexEnabled true
Then you will be able to use that class

Restricting file types upload component

I'm using the upload component of vaadin(7.1.9), now my trouble is that I'm not able to restrict what kind of files that can be sent with the upload component to the server, but I haven't found any API for that purpose. The only way is that of discarding file of wrong types after the upload.
public OutputStream receiveUpload(String filename, String mimeType) {
if(!checkIfAValidType(filename)){
upload.interruptUpload();
}
return out;
}
Is this a correct way?

No, its not the correct way. The fact is, Vaadin does provide many useful interfaces that you can use to monitor when the upload started, interrupted, finished or failed. Here is a list:
com.vaadin.ui.Upload.FailedListener;
com.vaadin.ui.Upload.FinishedListener;
com.vaadin.ui.Upload.ProgressListener;
com.vaadin.ui.Upload.Receiver;
com.vaadin.ui.Upload.StartedListener;
Here is a code snippet to give you an example:
#Override
public void uploadStarted(StartedEvent event) {
// TODO Auto-generated method stub
System.out.println("***Upload: uploadStarted()");
String contentType = event.getMIMEType();
boolean allowed = false;
for(int i=0;i<allowedMimeTypes.size();i++){
if(contentType.equalsIgnoreCase(allowedMimeTypes.get(i))){
allowed = true;
break;
}
}
if(allowed){
fileNameLabel.setValue(event.getFilename());
progressBar.setValue(0f);
progressBar.setVisible(true);
cancelButton.setVisible(true);
upload.setEnabled(false);
}else{
Notification.show("Error", "\nAllowed MIME: "+allowedMimeTypes, Type.ERROR_MESSAGE);
upload.interruptUpload();
}
}
Here, allowedMimeTypes is an array of mime-type strings.
ArrayList<String> allowedMimeTypes = new ArrayList<String>();
allowedMimeTypes.add("image/jpeg");
allowedMimeTypes.add("image/png");
I hope it helps you.

Can be done.
You can add this and it will work (all done by HTML 5 and most browsers now support accept attribute) - this is example for .csv files:
upload.setButtonCaption("Import");
JavaScript.getCurrent().execute("document.getElementsByClassName('gwt-FileUpload')[0].setAttribute('accept', '.csv')");

I think it's better to throw custom exception from Receiver's receiveUpload:
Upload upload = new Upload(null, new Upload.Receiver() {
#Override
public OutputStream receiveUpload(String filename, String mimeType) {
boolean typeSupported = /* do your check*/;
if (!typeSupported) {
throw new UnsupportedImageTypeException();
}
// continue returning correct stream
}
});
The exception is just a simple custom exception:
public class UnsupportedImageTypeException extends RuntimeException {
}
Then you just simply add a listener if the upload fails and check whether the reason is your exception:
upload.addFailedListener(new Upload.FailedListener() {
#Override
public void uploadFailed(Upload.FailedEvent event) {
if (event.getReason() instanceof UnsupportedImageTypeException) {
// do your stuff but probably don't log it as an error since it's not 'real' error
// better would be to show sth like a notification to inform your user
} else {
LOGGER.error("Upload failed, source={}, component={}", event.getSource(), event.getComponent());
}
}
});

public static boolean checkFileType(String mimeTypeToCheck) {
ArrayList allowedMimeTypes = new ArrayList();
allowedMimeTypes.add("image/jpeg");
allowedMimeTypes.add("application/pdf");
allowedMimeTypes.add("application/vnd.openxmlformats-officedocument.wordprocessingml.document");
allowedMimeTypes.add("image/png");
allowedMimeTypes.add("application/vnd.openxmlformats-officedocument.presentationml.presentation");
allowedMimeTypes.add("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
for (int i = 0; i < allowedMimeTypes.size(); i++) {
String temp = allowedMimeTypes.get(i);
if (temp.equalsIgnoreCase(mimeTypeToCheck)) {
return true;
}
}
return false;
}

I am working with Vaadin 8 and I there is no change in Upload class.
FileUploader receiver = new FileUploader();
Upload upload = new Upload();
upload.setAcceptMimeTypes("application/json");
upload.setButtonCaption("Open");
upload.setReceiver(receiver);
upload.addSucceededListener(receiver);
FileUploader is the class that I created that handles the upload process. Let me know if you need to see the implementation.

AbstractResource.ResourceResponse blocks user-interface while writing to OutputStream

I want to download a CSV file using Wicket, by implementing an AbstractResource. It looks something like this:
public class ExportCsvFileResource extends AbstractResource
{
#Override
protected AbstractResource.ResourceResponse newResourceResponse(IResource.Attributes attributes)
{
AbstractResource.ResourceResponse resourceResponse = new AbstractResource.ResourceResponse();
resourceResponse.setContentType("text/csv");
resourceResponse.setFileName("exported-contacts-file.csv");
resourceResponse.setTextEncoding("utf-8");
resourceResponse.setWriteCallback(new AbstractResource.WriteCallback()
{
#Override
public void writeData(IResource.Attributes attributes) throws IOException
{
OutputStream stream = attributes.getResponse().getOutputStream();
generateContentInBatches(stream);
}
});
return resourceResponse;
}
private void generateContentInBatches(OutputStream stream)
{
int numberOfChunks=//...
for (int i=0; i<numberOfChunks; i++)
{
byte[] contentChunk = retrieveContentFromBackend(i);
IOUtils.write(contentChunk, stream);
}
}
}
The problem is that, while the content is being generated with the retrieveContentFromBackend function (which is quite time consuming), the user interface is unresponsive. I click the buttons etc. but nothing happens, only after the file is done being generate can I use the interface again.
How do I avoid blocking the user interface while the file is being generated gradually?

Take a look at RequestMapperApplication and MapperDemoResourceReference from wicket-examples.
You can mount resource references:
mountResource("/print/${sheet}/${format}", new MapperDemoResourceReference());
To load such a resource without blocking the page, you'll have to render a link which triggers the resource directly:
add(new WebMarkupContainer("link")
{
#Override
protected void onComponentTag(ComponentTag tag)
{
super.onComponentTag(tag);
PageParameters parameters = new PageParameters();
parameters.add("sheet", "sheet1");
parameters.add("format", "A4");
tag.put("href", urlFor(new MapperDemoResourceReference(), parameters));
}
});

Here is an example of lazy loading:
http://www.wicket-library.com/wicket-examples/ajax/lazy-loading?1
I don't know how this works with your AbstractResource object but this should get you in the right direction.