Hi I am fairly an amateur at android so I might not be realizing something obvious.
I have a method that populates a global File Array variable with a list of flies in a specific directory. Problem is everything works fine if the directory has been made before by using my app to save a file there however when the user hasn't done that an error message is suppose to pop up saying they haven't saved a file yet.
I do a check if the directory exist but the app crashes when the directory has not been created.
This is what my code looks like any assistance would be appreciated
private void getTemplates()
{
//Gets file directory for saved templates
File finalMarkTemplateDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Final Mark Templates");
//Checks if path exists in other word if any templates have been saved before
if(finalMarkTemplateDir.exists())
{
templatePaths = finalMarkTemplateDir.listFiles();
}
else
{
Toast.makeText(this, "No previous templates have been saved.", Toast.LENGTH_LONG).show();
setResult(RESULT_CANCELED);
finish();
}
}
I am too an amateur, you have not created a file in your code, calling a new file() method does not create a file. Pls check that out
try {
finalMarkTemplateDir.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I managed to solve my problem when I call the setResult and finish methods I did not realize the flow of the program is returned to my onCreate method which meant the rest of my method calls in onCreate was still being called and they require the templatePaths array.
So basically I thought finish would stop the processing and move back to the calling class(using startActivityForResult). Instead I now call finish from my onCreate and use a boolean to determine if I could successfully access the directory.
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//setContentView(R.layout.dialog_load_template);
boolean fileLoadStatus = getTemplates();
if(fileLoadStatus)
{
populateTemplateList(templatePaths);
}
else
{
setResult(RESULT_CANCELED);
finish();
}
}
private boolean getTemplates()
{
boolean fileLoadStatus = false;
//Gets file directory for saved templates
File finalMarkTemplateDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/Final Mark Templates");
//Checks if path exists in other word if any templates have been saved before
if(finalMarkTemplateDir.isDirectory())
{
templatePaths = finalMarkTemplateDir.listFiles();
fileLoadStatus = true;
}
else
{
Toast.makeText(this, "No previous templates have been saved.", Toast.LENGTH_LONG).show();
}
return fileLoadStatus;
}
Related
I am working on an android app that is supposed to have copy of deleted image from android gallery. If the user wants to delete a picture from gallery, before he/she delete it, our app must save a copy of the image in a hidden folder.
I used SMS receiver but this one is some thing confusing.
public MyReceiver() {
}
#Override
public void onReceive(Context context, Intent intent) {
//activity which I want to perform here is to have a copy of deleted image in a hidden folder
}
You canot track a file when it is deleted. You can use file observer for track other cahnges in a folder.
observer = new FileObserver(Your_folder_Path) { // set up a file observer to watch this directory on sd card
#Override
public void onEvent(int event, String file) {
//if(event == FileObserver.CREATE && !file.equals(".probe")){ // check if its a "create" and not equal to .probe because thats created every time camera is launched
Log.d(TAG, "File created [" + pathToWatch + file + "]");
Toast.makeText(getBaseContext(), file + " was saved!", Toast.LENGTH_LONG).show();
//}
}
};
observer.startWatching();
i am using afilechooser for this purpose . and this is by default programmed to choose the items inside the folder and get you the path that is selected by the user.
but i want to use this as folder chooser where the user choose a location from internal memory of android device and then the app will save the file at that location.
so how do i do it.
the code i am using for this purpose is-
private void showChooser() {
// Use the GET_CONTENT intent from the utility class
Intent target = FileUtils.createGetContentIntent();
// Create the chooser Intent
Intent intent = Intent.createChooser(
target, getString(R.string.chooser_title));
try {
startActivityForResult(intent, REQUEST_CODE);
} catch (ActivityNotFoundException e) {
// The reason for the existence of aFileChooser
}
}
and i suspect the code can be changed to choose the folder instead of files. any suggestion can be helpful . please suggest if any other way to achieve what is want .
thank you
Looking at the github project in the url you posted, it doesn't look like this can be achieved. My claim is based on the following piece of code inside com.ipaulpro.afilechooser.FileChooserActivity class:
#Override
public void onFileSelected(File file) {
if (file != null) {
if (file.isDirectory()) {
replaceFragment(file);
} else {
finishWithResult(file);
}
} else {
Toast.makeText(FileChooserActivity.this, R.string.error_selecting_file,
Toast.LENGTH_SHORT).show();
}
}
just look at the if(file.isDirectory()) statement.
I have created an app in iOS that uses Parse to store data and also uses Parse Push for messaging between users. I am now converting the app to Android and trying to use the same Parse backend for both. I am successfully uploading/downloading data and I can even send a message from an Android user to a iOS user, but I can't get my Android device to receive messages. The underlining problem seems to be that I can't get the installation to work. I am calling this block of code from my onCreate function:
Parse.enableLocalDatastore(this);
Parse.initialize(this, "id1", "id2");
ParsePush.subscribeInBackground("", new SaveCallback() {
#Override
public void done(ParseException e) {
if (e == null) {
Log.d("com.parse.push", "successfully subscribed to the broadcast channel.");
} else {
Log.e("com.parse.push", "failed to subscribe for push", e);
}
}
});
ParseInstallation.getCurrentInstallation().saveInBackground();
After calling this code I check for a new installation in the database, but nothing ever shows up. It seems as though ParseInstallation.getCurrentInstallation().saveInBackground(); is not doing anything. Am I missing something?
the object associated with the installation on the given device does not have a row in the parse installation table, this is why you are getting the error, there are 2 possible solutions to this problem :
uninstalling the app, and reinstalling it (which is an unacceptable
solution), or
manually clearing the app parse cache. see the answer for how to do
that
This method must be called before you call Parse.initialize...
public static boolean deleteInstallationCache(Context context) {
boolean deletedParseFolder = false;
File cacheDir = context.getCacheDir();
File parseApp = new File(cacheDir.getParent(),"app_Parse");
File installationId = new File(parseApp,"installationId");
File currentInstallation = new File(parseApp,"currentInstallation");
if(installationId.exists()) {
deletedParseFolder = deletedParseFolder || installationId.delete();
}
if(currentInstallation.exists()) {
deletedParseFolder = deletedParseFolder && currentInstallation.delete();
}
return deletedParseFolder;
}
Alternatively, you can use package-private method
ParseInstallation.clearCurrentInstallationFromDisk(Context context)
public static void clearParseInstallation(Context context) {
try {
Method method = ParseInstallation.class.getDeclaredMethod("clearCurrentInstallationFromDisk", Context.class);
method.setAccessible(true);
method.invoke(null, context);
} catch (Exception e) {
Log.e(e);
}
}
add "bolts-android-x.x.x" lib in libs folder.
You can find it in the Parse SDK zip file
I have an interesting problem that I've never run into in programming before. I have an onClickListener that does a lot of username and password checks (makes sure the username is proper length, not taken, etc). I'm using MobDB, and I was using a conditional statement that would return a row if the username already existed. The problem is that the Listener skips the DB and goes to the final check that, if everything works, posts a new username and password to my DB. How can I make it wait for a response from the DB before skipping to the last check?
Here is the relevant code:
usernamecheck3 = true;
MobDB.getInstance().execute(APP_KEY, null, rd, null, false, new MobDBResponseListener() {
#Override public void mobDBSuccessResponse() {
usernamecheck3 = false;
Log.e("mobdbSuccess:", "success");
}
#Override public void mobDBResponse(Vector<HashMap<String, Object[]>> row) {
}
#Override public void mobDBResponse(String jsonObj) {
/*Log.e("mobdbSuccess:", "jsonObj");
Log.e("mobdbSuccess:", jsonObj);
JSONObject mainObject;
try {
mainObject = new JSONObject(jsonObj);
// need to parse the json object.
} catch (JSONException e1) {
e1.printStackTrace();
} */
}
#Override public void mobDBFileResponse(String fileName, byte[] fileData) {
//get file name with extension and file byte array
}
#Override public void mobDBErrorResponse(Integer errValue, String errMsg) {
usernamecheck3 = false;
Log.e("doesnt", "work");
}
});
if(usernamecheck3 == false){
Toast.makeText(getApplicationContext(), "Username is taken, please choose another", Toast.LENGTH_SHORT).show();
}
Basically the check always returns true, and then logcat will say mobdbSuccess: success, which should have set the Bool to false.
Thanks.
MobDBResponseListener is executing on a different thread. What happens here is that the processing is split, while a thread is doing the query, the main thread on which you added the listener, skips right ahead to the validation. Your best bet is to place the validation inside the MobDBResponseListener, on the mobDBResponse method.
Try to debug your code and calls, the Listener may be using an async task. If so, you may do anything you please from the response method, as it will be executing in the main thread again. Otherwise, you should look at solutions that handle threaded execution like Handlers
I have a DropboxHelper Class that is handling downloading and uploading from dropbox.
Downloading works fine but when I try to upload from dropbox the first time the code is called. The following Line is false
if (dropboxFileSystem.isFile(dropboxPath)) {
}
It returns false. Tell the app to try again and this time it sees the file and uploads it to the app. Below is some of the code I am using for the class. Debug seems to incdicate the dropbox api has not completing started / synced the first time
public class DropBoxHelper {
public DropBoxHelper(Context pContext) {
context = pContext;
defineVariables();
}
private void defineVariables() {
dropboxAccountManager = DbxAccountManager.getInstance(context.getApplicationContext(), DROPBOX_APP_KEY, DROPBOX_APP_SECRET);
dropboxPath = new DbxPath(DbxPath.ROOT, DROPBOX_FILE_NAME);
}
public boolean importFromDropbox() {
try {
dropboxFileSystem = DbxFileSystem.forAccount(dropboxAccountManager.getLinkedAccount());
if (dropboxFileSystem.isFile(dropboxPath)) {
DbxFile databaseFileonDropbox = dropboxFileSystem.open(dropboxPath);
try {
// Do Copy
} finally {
Log.i(DEBUG_TAG, "Closing File");
databaseFileonDropbox.close();
}
}
Any ideas on why the copy fails first time.
Thanks
I'm not 100% sure, but I believe you need to use dropboxFileSystem.awaitFirstSync() to make sure at least one sync with the server has happened before you try to find the file.
An alternative might be to just call dropboxFileSystem.open(...) directly and handle the exception that's raised if the file doesn't exist.