We Keep Coding

File not being renamed in Android 10

I wrote a solution for renaming files, but nothing happens in Android 10, although in 11 and above it is renamed normally.
public class PathDiv {
public static String dev(String path){
return path.replaceAll("^(.*)/.*?$","$1");
}
public static void renameFilesInDir(String path, String dirIn, String ext) {
File checkFile = new File(path);
if (checkFile.isFile()) {
try {
checkFile.renameTo(new File(dirIn, ext));
} catch (Exception e) {
e.printStackTrace();
}
}
}
path: /storage/emulated/0/Music/04. Kasger - Highland.mp3 dirIn: /storage/emulated/0/Music ext: Highland.mp3
PathDiv.renameFilesInDir(songItem.realUri,PathDiv.dev(songItem.realUri),newName.toString())
What's the problem?

In Android 10 and Higher Version of android, you can't Rename or Delete directly.
For Rename or Delete a media file you want to send a request.
Here Read Android Official Document how to create a request
For your information, to Delete a media file Dependency Available here you can use it easily it's created by me
checkFile.renameTo(new File(dirIn, ext)); It Also Works for this you want to add ACTION_MANAGE_ALL_FILES_ACCESS_PERMISSION permission in your app but before using this permission please refer to Google Play Police Update

Opening PDF file stored in resources folder raises Exception

I wrote a program in which a pdf file should be opened on an Action Event (you can have a look at my code below).
menuElementHilfe.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
File hilfe = new File ("src\\resources\\Hilfe.pdf");
try {
java.awt.Desktop.getDesktop().open(hilfe);
} catch (IOException e) {
e.printStackTrace();
}
}
});
If I execute the program via Eclipse everything works, but after exporting as a runnable jar I get following Exception:
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: The file: src\resources\Hilfe.pdf doesn't exist.
Any Feedback is appreciated

The way you're retrieving resources may be the problem. try this :
menuElementHilfe.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
File hilfe = new File(getClass().getResource("/resources/Hilfe.pdf").getFile());
try {
java.awt.Desktop.getDesktop().open(hilfe);
} catch (IOException e) {
e.printStackTrace();
}
}
});
When running in Eclipse, you are targeting a file in your build path.
When running from JAR/WAR, the URL is different and look like "jar:file:/your-path/your-jar.jar!/Hilfe.pdf" which is not what you set when calling new File(...) So to get the right URL for internal resources, you have to use methods like getResource or getResourceAsStream depending on your needs.
Check out following explanations for more information :)
https://docs.oracle.com/javase/8/docs/technotes/guides/lang/resources.html
[EDIT]
I assume you're working on some Swing app, but I dont know if you're aware that doing some task like that in your AWT-EventQueue thread will freeze your UI.
To prevent that you have to run UI-unrelated stuff in another thread.
This is made using SwingUtilities.invokeLater (Java 5 and prior) method and/or the SwingWorker class (since Java 6).
as mentionned in this answer
You should put the previous solution in something like that :
SwingUtilities.invokeLater(new Runnable() {
public void run() {
// Your UI unrelated code here
}
});

The resource can be packed in the application jar, hence File (physical disk file)
is not possible. Copy it to a temporary file, so that the desktop can open it.
menuElementHilfe.addActionListener(evt -> {
Path tmp = Files.createTempFile("hilfe-", ".pdf");
Files.copy(getClass().getResourceAsStream("/Hilfe.pdf"), tmp);
try {
Desktop.getDesktop().open(tmp.toFile());
tmp.toFile().deleteOnExit();
} catch (IOException e) {
e.printStackTrace();
}
});
An other difference is the forward slash, and that the path is case-sensitive, opposed to Windows File.
After problems
menuElementHilfe.addActionListener(evt ->
SwingUtilities.invokeLater(() -> {
Path tmp = Files.createTempFile("hilfe-", ".pdf");
Logger.getLogger(getClass().getName()).log(Level.INFO, "actionPerformed "
+ tmp + "; event: " + evt);
Files.copy(getClass().getResourceAsStream("/resources/Hilfe.pdf"), tmp);
try {
Desktop.getDesktop().open(tmp.toFile());
//tmp.toFile().deleteOnExit();
} catch (IOException e) {
Logger.getLogger(getClass().getName()).log(Level.WARN, "Error with " + tmp,
e);
}
}));
I did not delete, so the Desktop access can live longer than the java app.
I did an invokeLater in order to have no frozen GUI on the actionPerformed.
I added logging to see every call to actionPerformed

Not able to open application package directory of my Android application

I am trying to write a text file to internal storage of my android application. But it is not possible for me to see if the file is generated or not.
My text file is stored in the following path:
data/data/"MyApplcationPackageName"/files/MyFile.txt
Permission : drwxrwx-x
I have tried the following things -
1) Using device file explorer:
Device file explorer does not open my application package. it gives following error if I try to open it.
Device File Explorer
2) Terminal:
I have also tried opening it using adb in the terminal. But when I try to open files inside my application package it says permission denied.
adb terminal
Please let me know how I can open my text file for debugging. Thanks in advance.
public static void StoreDB() {
if(isExternalStorageWritable() && checkPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
File file = getFinalDir();
try {
FileOutputStream fos = new FileOutputStream(file);
fos.write("something".getBytes());
fos.close();
ToastUtil.showToast(Resource.getAppContext(),"File Saved");
} catch (IOException e) {
Log.e("StoreDB", "Exception");
e.printStackTrace();
}
}
}
public static boolean isExternalStorageWritable() {
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
Log.d("External storage", "Writable");
return true;
}
Log.d("External storage", "Not Writable");
return false;
}
public static boolean checkPermission(String Permission){
int check = ContextCompat.checkSelfPermission(Resource.getAppContext(),Permission);
boolean Perm = (check == PackageManager.PERMISSION_GRANTED);
Log.d("Check Permission", "Result: " + Perm);
return Perm;
}
private static File getFinalDir() {
return createDirIfNotExist(Environment.getExternalStorageDirectory().getPath() + "/Co_Ordinate.txt/");
}
public static File createDirIfNotExist(String path) {
File dir = new File(path);
if (!dir.exists()) {
dir.mkdirs();
}
return dir;
}
Now I am trying to put the file in external storage. Above code always gives IO exception.

You need to root your phone to view those files. Or you can do it on an emulator by using the Device File Explorer.
EDIT: Or just use an unprotected file path. This will create the directory. After that you just need to save the .txt file to that directory.
private static File getFinalDir() {
return createDirIfNotExist(Environment.getExternalStorageDirectory().getPath() + "/MyAppName/");
}
public static File createDirIfNotExist(String path) {
File dir = new File(path);
if (!dir.exists()) {
dir.mkdirs();
}
return dir;
}

You can do this with Emulator. Run your app in emulator and go to Android Device monitor
Choose device, go to File Explorer menu and search your text file in data folder

Download Revision history files from Google Drive

I am using the following code to get all the revisions on a particular file uploaded in Google Drive. I am able to get the link and download the versions but when any other user access the application he is not able to download the file from the provided link.
To get all Revision of File:
private static List<Revision> retrieveRevisions() {
try {
String fileId="0BylJDrKIrQebRkpnNEFmZVF3Q3c";
Drive service= GoogleDriveUtil.getDrive();
System.out.println(service+"Drive is Here");
RevisionList revisions = service.revisions().list(fileId).execute();
List<Revision> revisionList = revisions.getItems();
for(Revision revision: revisionList){
System.out.println("Revision "+revision.getOriginalFilename()+" "+revision.getId()+"revision.getDownloadUrl()");
}
return revisionList;
} catch (IOException e) {
System.out.println("An error occurred: " + e);
}
return null;
}
Suggestions will be appreciated

Accessing a PDF in Jar

I'm creating a Java application using Netbeans. From the 'Help' Menu item, I'm required to open a PDF file. When I run the application via Netbeans, the document opens, but on opening via the jar file, it isn't opening. Is there anything that can be done?
m_aboutItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Runtime rt = Runtime.getRuntime();
URL link2=getClass().getResource("/newpkg/Documentation.pdf");
String link=link2.toString();
link=link.substring(6);
System.out.println(link);
System.out.println(link2);
String link3="E:/new/build/classes/newpkg/Documentation.pdf";
try {
Process proc = rt.exec("rundll32.exe url.dll,FileProtocolHandler " + link3);
} catch (IOException ex) {
Logger.getLogger(Menubar1.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
The two outputs are as follows:
E:/new/build/classes/newpkg/Documentation.pdf
file:/E:/new/build/classes/newpkg/Documentation.pdf
Consider the above code snippet. On printing 'link',we can see that it is exactly same as the hard coded 'link3'. On using the hard coded 'link3' , the PDF file gets opened from jar application. But when we use link, though it is exactly same as 'link3', the PDF doesn't open.

This is most likely related to the incorrect PDF resource loading. In the IDE you have the PDF file either as part of the project structure or with a directly specified relative path. When a packaged application is running it does not see the resource.
EDIT:
Your code reveals the problem as I have described. The following method could be used to properly identify resource path.
public static URL getURL(final String pathAndFileName) {
return Thread.currentThread().getContextClassLoader().getResource(pathAndFileName);
}
Pls refer to this question, which might provide additional information.

Try out this:
m_aboutItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (Desktop.isDesktopSupported()) {
Desktop desktop = Desktop.getDesktop();
URL link2=Menubar1.class.getResource("/newpkg/Documentation.pdf");
String link=link2.toString();
link=link.substring(6);
System.out.println(link);
File file=new File(link);
System.out.println(file);
try {
desktop.open(file);
} catch (IOException ex) {
Logger.getLogger(Menubar1.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
});