I made a DRM media player app in Xamarin which drops course.licns and pass.licns files in internal memory in app directory for reading correct key.
It's working fine in Android 10 but it's not working in above versions like Android 11 and 12 when I put course name and key then app added both files but can't read it again when I want to play a video. The same thing is working fine on lower versions.
My code:
using System;
using System.Text;
using System.IO;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
using Android.OS;
namespace MediaElement
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class Add : ContentPage
{
public Add()
{
InitializeComponent();
}
async void Appears(object sender, EventArgs e)
{
try
{
this.FindByName<Entry>("ID").Text =Helper. GetIMEI();
}
catch (Exception e2)
{
await DisplayAlert("Error!", e2.Message, "Ok");
}
}
public static string Pass()
{
return Path.Combine((string)System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "pass.licns");
//return Path.Combine((string)System.Environment.GetFolderPath(System.Environment.SpecialFolder.LocalApplicationData), "pass.licns");
}
public static string Course()
{
//return Path.Combine((string)System.Environment.GetFolderPath(System.Environment.SpecialFolder.LocalApplicationData), "course.licns");
return Path.Combine((string)System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "course.licns");
}
void Register(object sender, EventArgs e)
{
try
{
string key = this.FindByName<Entry>("Key").Text.Trim();
string Name = this.FindByName<Entry>("Name").Text.Trim();
if (key== string.Empty || Name == string.Empty) { throw new Exception("Key or Name is empty"); }
if (!IsBase(key)) { throw new Exception("Invalid key!"); }
if (!IsValidID(key)) { throw new Exception("This key is not designed for your ID."); }
if (File.Exists(Pass()) && File.Exists(Course()))
{
if (File.ReadAllText(Pass()).Contains(key) || File.ReadAllText(Course()).Contains(Name)){ throw new Exception("Key or Course Already exists."); }
}
File.AppendAllText(Pass(), key+",");
File.AppendAllText(Course(), Name + ",");
DisplayAlert("Success", "License added successfully.", "Ok");
}
catch (Exception e2)
{
DisplayAlert("Error", e2.Message, "Ok");
}
}
bool IsBase(string base64)
{
try
{
if (base64 == Convert.ToBase64String(Convert.FromBase64String(base64))) { return true; }
}
catch (Exception)
{
}
return false;
}
public static bool IsValidID(string key)
{
return Encoding.ASCII.GetString(MainPage.Decrypt(Convert.FromBase64String(key),Helper. IDkey)).Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries)[0].ToString() == Helper. GetIMEI();
}
}
}
Note:
I don't want to use All file access permissions due to so many restrictions in Google Play Store and my App is only accessing a particular file. Is there a proper way for upper versions?
Related
I created a Websocket service class using KOUSH library https://github.com/koush/AndroidAsync#can-also-create-web-sockets
Now I want to check if the Websocket is connected to my server from my mainActivity. Do you know how I can check this?
thanks
AsyncHttpClient.getDefaultInstance().websocket(get, "my-protocol", new WebSocketConnectCallback() {
#Override
public void onCompleted(Exception ex, WebSocket webSocket) {
if (ex != null) {
ex.printStackTrace();
return;
}
webSocket.send("a string");
webSocket.send(new byte[10]);
webSocket.setStringCallback(new StringCallback() {
public void onStringAvailable(String s) {
System.out.println("I got a string: " + s);
}
});
webSocket.setDataCallback(new DataCallback() {
public void onDataAvailable(ByteBufferList byteBufferList) {
System.out.println("I got some bytes!");
// note that this data has been read
byteBufferList.recycle();
}
});
}
});
You can do something like this:
if (mWebSocketClient.isOpen) {
mWebSocketClient.send(jObj.toString())
} else {
try {
client.connectWebSocket(p0)
mWebSocketClient.send(jObj.toString())
} catch (e : Exception){
Toast.makeText(p0, "not connected $e", Toast.LENGTH_LONG).show()
}
}
The solution is to save the result of this Function to a local Websocket Variable , and then you check its status :
WebSocket webSocket=null;
try {
webSocket=AsyncHttpClient.getDefaultInstance().websocket(get, "my-protocol", new WebSocketConnectCallback() {
#Override
public void onCompleted(Exception ex, WebSocket webSocket) {
if (ex != null) {
ex.printStackTrace();
return;
}
webSocket.send("a string");
webSocket.send(new byte[10]);
webSocket.setStringCallback(new StringCallback() {
public void onStringAvailable(String s) {
System.out.println("I got a string: " + s);
}
});
webSocket.setDataCallback(new DataCallback() {
public void onDataAvailable(ByteBufferList byteBufferList) {
System.out.println("I got some bytes!");
// note that this data has been read
byteBufferList.recycle();
}
});
}
}).get();
}catch(InterruptedException e){
//handle exception
}catch(ExecutionException e){
//handle exception
}
if(websocket!=null && websocket.isOpen()){
//websocket is working fine
}
you can use other statements like websocket.isClosed();
public class Midlet extends MIDlet implements CommandListener{
Player p;
public void startApp() {
Display.getDisplay(this).setCurrent(new SongsList(this));
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
notifyDestroyed();
}
public void commandAction(Command cmnd, Displayable dsplbl) {
if (cmnd.getLabel().equals("Exit"))
{
destroyApp(true);
}
else
{
try {
//InputStream is = getClass().getResourceAsStream("/res/getlucky.mpeg");
//p = Manager.createPlayer(is, "audio/mpeg");
p = Manager.createPlayer("http://puu.sh/6n9jC.mp3");
p.realize();
p.start();
} catch (IOException ex) {
ex.printStackTrace();
} catch (MediaException ex) {
ex.printStackTrace();
}
}
}
}
this is the songslist class :
public class SongsList extends List{
public SongsList(Midlet midlet)
{
super("Songs", List.IMPLICIT);
append("get lucky", null);
addCommand(new Command("Exit", Command.EXIT, 0));
addCommand(new Command("Select", Command.OK, 0));
setCommandListener(midlet);
}
}
tried use via file stored in project (its under src/res):
inputStream = getClass().getResourceAsStream("res/getlucky.mpg");
audioPlayer = Manager.createPlayer(inputStream, "audio/mpg");
as well as from HTTP:
//audioPlayer = Manager.createPlayer("http://puu.sh/6n9jC.mp3");
Nothing works, what am I doing wrong?
EDIT:
I've tried to delete my application and just copy paste it to a new project and it worked for some reason.. now I encounter new problems:
1) I try to play a song - this is the link http://puu.sh/6n9jC.mp3
its not playing so I guess there's a limited file size for what can be played can someone tell me what is this limit ?
2) Im trying to record the audio with RecordPlayer but its always null
public AudioAnalyzer()
{
try {
thread = new Thread(this);
recordFinished = false;
//inputStream = getClass().getResourceAsStream("res/getlucky.mpg");
//audioPlayer = Manager.createPlayer(inputStream, "audio/mpg");
audioPlayer = Manager.createPlayer("http://puu.sh/35YTG.mp3");
//audioPlayer = Manager.createPlayer("http://puu.sh/6n9jC.mp3");
audioPlayer.realize();
System.out.println(System.getProperty("supports.audio.capture"));
recordControl = (RecordControl)audioPlayer.getControl("RecordControl");
recordOutput = new ByteArrayOutputStream();
recordControl.setRecordStream(recordOutput);
recordControl.startRecord();
audioPlayer.start();
//thread.start();
} catch (MediaException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
}
I even tried to print if the system is supporting audio capture and the result were true but I get NullPointException at this line :
recordOutput = new ByteArrayOutputStream();
although I tried to get the recordcontrol from the player it is still null :
recordControl = (RecordControl)audioPlayer.getControl("RecordControl");
I think I read that it'll always give NullPointerException unless you run it on a real device and not an emulator is that true ? can someone verify it ? and if so what can I do if I don't own a device currently any other way to use recordcontrol feature in emulator (assuming recordcontrol isn't working on emulators).
File size is 8MB (maybe play on your phone), try to this code
public void initMedia(final String aFileUrl) {
if (m_player == null) {
try {
m_player = Manager.createPlayer(aFileUrl);
m_player.addPlayerListener(this);
m_player.realize();
m_player.prefetch();
m_volumeControl = (VolumeControl) m_player.getControl("VolumeControl");
} catch (IOException ex) {
} catch (Exception ex) {
} catch (OutOfMemoryError e) {
}
}
}
In your code, i guess you miss "m_player.prefetch()", try this. And print your Exception message...
This code in general for file, resourcce, http...
public void initMedia(final String aProtocol, final String aMediaSource) {
if (m_player == null) {
try {
if (aMediaSource.indexOf("file://") == 0) {
InputStream iRecordStream = Connector.openInputStream(aMediaSource);
m_player = Manager.createPlayer(iRecordStream, "audio/amr");
} else {
m_player = Manager.createPlayer(aProtocol);
}
m_player.addPlayerListener(this);
m_player.realize();
boolean isPrefetch = true;
try {
m_player.prefetch();
} catch (Exception ex) {
isPrefetch = false;
}
// trick to pass prefetch error
if (!isPrefetch) {
if (m_player != null) {
m_player.close();
m_player = null;
}
if (aMediaSource.indexOf("file://") == 0) {
InputStream iRecordStream = Connector.openInputStream(aMediaSource);
m_player = Manager.createPlayer(iRecordStream, "audio/amr");
} else {
m_player = Manager.createPlayer(aProtocol);
}
m_player.addPlayerListener(this);
m_player.realize();
m_player.prefetch();
}
m_volumeControl = (VolumeControl) m_player.getControl("VolumeControl");
} catch (IOException ex) {
} catch (Exception ex) {
} catch (OutOfMemoryError e) {
}
}
}
In general when it comes to J2ME development, you should always test your app on multiple real devices.
Emulators can't be trusted.
Also, J2ME is very fragmented, and various devices have various bugs and behaves differently with the same code. This will affect any app on many areas. One area being audio playback.
For example, some devices requires that you use the realize() and prefetch() methods, while other devices will crash if you use prefetch(). The only possible solution (if you wish to support as many devices as possible) is to use multiple try/catch blocks.
See this link for a detailed explanation and other tips'n'tricks on audio playback with MIDP2.0
http://indiegamemusic.com/help.php?id=1
I have to programmatically retrieve permissions from the manifest.xml of an android application and I don't know how to do it.
I read the post here but I am not entirely satisfied by the answers.
I guess there should be a class in the android API which would allow to retrieve information from the manifest.
Thank you.
You can get an application's requested permissions (they may not be granted) using PackageManager:
PackageInfo info = getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_PERMISSIONS);
String[] permissions = info.requestedPermissions;//This array contains the requested permissions.
I have used this in a utility method to check if the expected permission is declared:
//for example, permission can be "android.permission.WRITE_EXTERNAL_STORAGE"
public boolean hasPermission(String permission)
{
try {
PackageInfo info = getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_PERMISSIONS);
if (info.requestedPermissions != null) {
for (String p : info.requestedPermissions) {
if (p.equals(permission)) {
return true;
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
Here's a useful utility method that does just that (in both Java & Kotlin).
Java
public static String[] retrievePermissions(Context context) {
final var pkgName = context.getPackageName();
try {
return context
.getPackageManager()
.getPackageInfo(pkgName, PackageManager.GET_PERMISSIONS)
.requestedPermissions;
} catch (PackageManager.NameNotFoundException e) {
return new String[0];
// Better to throw a custom exception since this should never happen unless the API has changed somehow.
}
}
Kotlin
fun retrievePermissions(context: Context): Array<String> {
val pkgName = context.getPackageName()
try {
return context
.packageManager
.getPackageInfo(pkgName, PackageManager.GET_PERMISSIONS)
.requestedPermissions
} catch (e: PackageManager.NameNotFoundException) {
return emptyArray<String>()
// Better to throw a custom exception since this should never happen unless the API has changed somehow.
}
}
You can get a working class from this gist.
Use this:
public static String getListOfPermissions(final Context context)
{
String _permissions = "";
try
{
final AssetManager _am = context.createPackageContext(context.getPackageName(), 0).getAssets();
final XmlResourceParser _xmlParser = _am.openXmlResourceParser(0, "AndroidManifest.xml");
int _eventType = _xmlParser.getEventType();
while (_eventType != XmlPullParser.END_DOCUMENT)
{
if ((_eventType == XmlPullParser.START_TAG) && "uses-permission".equals(_xmlParser.getName()))
{
for (byte i = 0; i < _xmlParser.getAttributeCount(); i ++)
{
if (_xmlParser.getAttributeName(i).equals("name"))
{
_permissions += _xmlParser.getAttributeValue(i) + "\n";
}
}
}
_eventType = _xmlParser.nextToken();
}
_xmlParser.close(); // Pervents memory leak.
}
catch (final XmlPullParserException exception)
{
exception.printStackTrace();
}
catch (final PackageManager.NameNotFoundException exception)
{
exception.printStackTrace();
}
catch (final IOException exception)
{
exception.printStackTrace();
}
return _permissions;
}
// Test: Log.wtf("test", getListOfPermissions(getApplicationContext()));
If anyone is looking for a short Kotlin Version
fun Manifest.getDeclaredPermissions(context: Context): Array<String> {
return context.packageManager.getPackageInfo(context.packageName, PackageManager.GET_PERMISSIONS).requestedPermissions
}
I have a simple C# code, "using System.Xml"
private void ShowPermissions()
{
XmlDocument doc = new XmlDocument();
doc.Load("c:\\manifest.xml");
XmlNodeList nodeList = doc.GetElementsByTagName("uses-permission");
foreach(XmlNode node in nodeList)
{
XmlAttributeCollection Attr = node.Attributes;
string Permission=Attr["android:permission"].Value;
MessageBox.Show(Permission);
}
}
I have encountered this error:
java.lang.UnsupportedOperationException: Desktop API is not supported on the current platform
I would open a file from my java application. I use this method:
Desktop.getDesktop().open(new File(report.html"));
How can i solve this problem?
Basically, the problem is that Java Desktop integration doesn't work well on Linux.
It was designed to work good with Windows; something works on other systems, but nobody really cared to add proper support for those. Even if you install the required 'gnome libraries', the results will be poor.
I've faced the very same problem a while ago, and came up with the class below.
The goal is achieved by using system-specific commands:
KDE: kde-open
GNOME: gnome-open
Any X-server system: xdg-open
MAC: open
Windows: explorer
If none of those works, it tries the implementation provided by Java Desktop.
Because this one usually fails, it's tried as the last resort.
DesktopApi class
This class provides static methods open, browse and edit.
It is tested to work on Linux (Kde and Gnome), Windows and Mac.
If you use it, please give me credit.
package net.mightypork.rpack.utils;
import java.awt.Desktop;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
public class DesktopApi {
public static boolean browse(URI uri) {
if (openSystemSpecific(uri.toString())) return true;
if (browseDESKTOP(uri)) return true;
return false;
}
public static boolean open(File file) {
if (openSystemSpecific(file.getPath())) return true;
if (openDESKTOP(file)) return true;
return false;
}
public static boolean edit(File file) {
// you can try something like
// runCommand("gimp", "%s", file.getPath())
// based on user preferences.
if (openSystemSpecific(file.getPath())) return true;
if (editDESKTOP(file)) return true;
return false;
}
private static boolean openSystemSpecific(String what) {
EnumOS os = getOs();
if (os.isLinux()) {
if (runCommand("kde-open", "%s", what)) return true;
if (runCommand("gnome-open", "%s", what)) return true;
if (runCommand("xdg-open", "%s", what)) return true;
}
if (os.isMac()) {
if (runCommand("open", "%s", what)) return true;
}
if (os.isWindows()) {
if (runCommand("explorer", "%s", what)) return true;
}
return false;
}
private static boolean browseDESKTOP(URI uri) {
logOut("Trying to use Desktop.getDesktop().browse() with " + uri.toString());
try {
if (!Desktop.isDesktopSupported()) {
logErr("Platform is not supported.");
return false;
}
if (!Desktop.getDesktop().isSupported(Desktop.Action.BROWSE)) {
logErr("BROWSE is not supported.");
return false;
}
Desktop.getDesktop().browse(uri);
return true;
} catch (Throwable t) {
logErr("Error using desktop browse.", t);
return false;
}
}
private static boolean openDESKTOP(File file) {
logOut("Trying to use Desktop.getDesktop().open() with " + file.toString());
try {
if (!Desktop.isDesktopSupported()) {
logErr("Platform is not supported.");
return false;
}
if (!Desktop.getDesktop().isSupported(Desktop.Action.OPEN)) {
logErr("OPEN is not supported.");
return false;
}
Desktop.getDesktop().open(file);
return true;
} catch (Throwable t) {
logErr("Error using desktop open.", t);
return false;
}
}
private static boolean editDESKTOP(File file) {
logOut("Trying to use Desktop.getDesktop().edit() with " + file);
try {
if (!Desktop.isDesktopSupported()) {
logErr("Platform is not supported.");
return false;
}
if (!Desktop.getDesktop().isSupported(Desktop.Action.EDIT)) {
logErr("EDIT is not supported.");
return false;
}
Desktop.getDesktop().edit(file);
return true;
} catch (Throwable t) {
logErr("Error using desktop edit.", t);
return false;
}
}
private static boolean runCommand(String command, String args, String file) {
logOut("Trying to exec:\n cmd = " + command + "\n args = " + args + "\n %s = " + file);
String[] parts = prepareCommand(command, args, file);
try {
Process p = Runtime.getRuntime().exec(parts);
if (p == null) return false;
try {
int retval = p.exitValue();
if (retval == 0) {
logErr("Process ended immediately.");
return false;
} else {
logErr("Process crashed.");
return false;
}
} catch (IllegalThreadStateException itse) {
logErr("Process is running.");
return true;
}
} catch (IOException e) {
logErr("Error running command.", e);
return false;
}
}
private static String[] prepareCommand(String command, String args, String file) {
List<String> parts = new ArrayList<String>();
parts.add(command);
if (args != null) {
for (String s : args.split(" ")) {
s = String.format(s, file); // put in the filename thing
parts.add(s.trim());
}
}
return parts.toArray(new String[parts.size()]);
}
private static void logErr(String msg, Throwable t) {
System.err.println(msg);
t.printStackTrace();
}
private static void logErr(String msg) {
System.err.println(msg);
}
private static void logOut(String msg) {
System.out.println(msg);
}
public static enum EnumOS {
linux, macos, solaris, unknown, windows;
public boolean isLinux() {
return this == linux || this == solaris;
}
public boolean isMac() {
return this == macos;
}
public boolean isWindows() {
return this == windows;
}
}
public static EnumOS getOs() {
String s = System.getProperty("os.name").toLowerCase();
if (s.contains("win")) {
return EnumOS.windows;
}
if (s.contains("mac")) {
return EnumOS.macos;
}
if (s.contains("solaris")) {
return EnumOS.solaris;
}
if (s.contains("sunos")) {
return EnumOS.solaris;
}
if (s.contains("linux")) {
return EnumOS.linux;
}
if (s.contains("unix")) {
return EnumOS.linux;
} else {
return EnumOS.unknown;
}
}
}
I am using Ubuntu 12.04 LTS 64-bit with Oracle jdk1.6.0_45 and was having the same problem.
I’m running gnome-classic as the desktop instead of Unity. This is what worked for me:
sudo apt-get install libgnome2-0
After installing this package I restarted my Java Swing app and Desktop.getDesktop().open(new File("myfile")); worked just fine.
The Desktop class is not supported on all systems.
From the Java Swing tutorial How to Integrate with the Desktop Class:
Use the isDesktopSupported() method to determine whether the Desktop API is available. On the Solaris Operating System and the Linux platform, this API is dependent on Gnome libraries. If those libraries are unavailable, this method will return false. After determining that the Desktop API is supported, that is, the isDesktopSupported() returns true, the application can retrieve a Desktop instance using the static method getDesktop().
In any case, it would be best to provide an alternative way to open a file if there is no support for Desktop.
Support varies between implementations on the various JDKs. I encountered the "UnsupportedOperationException" using OpenJDK 1.7.0. Switching to the Oracle JDK 1.7 worked.
Where practical, you may be able to switch JDKs or suggest that your users switch JDKs to enable a certain feature.
Iam working in a desktop application for windows version using java. In my application there is a requirement to search all .php
i use recursive methods;
and REGEX
my code :
import java.io.File;
public class Copier {
public static void find(String source,String rep)
{
File src=new File(rep);
if(src.exists() && src.isDirectory())
{
String[] tab=src.list();
for(String s:tab)
{
File srcc=new File(rep+"\\"+s);
if(srcc.isFile())
{
if(srcc.getName().matches(".*"+source+"$"))
System.out.println(s);
}
else
find(source,srcc.getAbsolutePath());
}
}
}
public static void main(String[] args)
{
find(".php","C:\\");
}
}
But i have this exception :
Exception in thread "main" java.lang.NullPointerException
at Copier.find(Copier.java:11)
at Copier.find(Copier.java:21)
at Copier.main(Copier.java:28)
src.list() returns null. It probably happens because you (current user) does not have access rights to the directory. I guess it is about C:\ (the root directory of disk C). This often happens especially on Windows 7.
First try to debug your code using directory where you have access rights. Then fix your code to care about nulls. Then try to run your program as an administrator.
Change main like below, for debugging purpose.
public static void main(String[] args)
{
try {
find(".php","C:\\");
} catch (Exception e) {
e.printStackTrace();
}
}
And add a null check in
if (src != null && src.exists() && src.isDirectory())
Edit:
Below works fine for me, (I am using windows 7).
import java.io.File;
public class Copier {
public static void find(String source,String rep) {
File src = new File(rep);
if (src!= null && src.exists() && src.isDirectory()) {
String[] tab = src.list();
if (tab != null) {
for(String s : tab) {
File srcc = new File(rep+"\\"+s);
if (srcc.isFile()) {
if (srcc.getName().matches(".*"+source+"$")) {
System.out.println(s);
}
} else {
find(source,srcc.getAbsolutePath());
}
}
} else {
//System.out.println(" list is null");
}
}
}
public static void main(String[] args) {
try {
find(".java", "C:\\");
} catch (Exception e) {
e.printStackTrace();
}
}
}