Develop Reference

Streaming CPU and Ram or sensor data usage from android studio to PowerBI streaming data set ( through REST- end point )

I Have successfully implemented a realtime powerbi dashboard ( to monitor CPU and Ram usage ) through Rest API i have used the following powershell script to read values and sent these values via 3 variables Time , Ram and CPU through powershell code to a PowerBi provided end point , as follows ( the end point )
https://api.powerbi.com/beta/xxxxxx-xxxxx-xxxx-xxxx-xxxxxxxxxxxx/datasets/xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx/rows?key=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx%xxxxxxx%xxxxx%xxxx%xxxxxxxxxxxxxxx%3D%3D
Seeking help want to send these variables through an android app the variables will remain same ( Time , CPU and RAm usage ) but this time it will be from android app ( app is already working fine and capturing the ram and CPU info through Java ,
i have tried Retrofit , Volley example codes but still not able to figure out that how i can send these 3 variables to following power BI streaming data sets end point ? I am new to REST so seeking help to send ( post these 3 variables in Json format to following power BI end point API as shown in the following powershell code.
I have also tried following HTTP based code but not able to figure out if i can put the following power BI push URL in the following code new HttpPost("http://yoururl"); replaced with power BI URL ?
JSONObject json = new JSONObject();
json.put("CPU", "15%");
json.put("RAM", "4 GB");
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
try {
HttpPost request = new HttpPost("http://yoururl");
StringEntity params = new StringEntity(json.toString());
request.addHeader("content-type", "application/json");
request.setEntity(params);
httpClient.execute(request);
// handle response here...
} catch (Exception ex) {
// handle exception here
} finally {
httpClient.close();
}
All i have got from power BI is following push URL
while($true)
{
$ComputerCPU = (Get-WmiObject -Class win32_processor -ErrorAction Stop | Measure-Object -Property LoadPercentage -Average | Select-Object Average).Average
$ComputerMemory = Get-WmiObject -Class win32_operatingsystem -ErrorAction Stop
$UsedMemory = $ComputerMemory.TotalVisibleMemorySize - $ComputerMemory.FreePhysicalMemory
$Memory = (($UsedMemory/ $ComputerMemory.TotalVisibleMemorySize)*100)
$RoundMemory = [math]::Round($Memory, 2)
$Date = Get-Date -DisplayHint Date -Format MM/dd/yyyy
$Time123 = Get-Date -DisplayHint Time -Format HH:MM:ss
#$Date
#$Time123
#$ComputerCPU
#$RoundMemory
$endpoint = "https://api.powerbi.com/beta/xxxxxxxxxxx/datasets/xxxxxxxx/rows?key=xxx%xxxxxx%xxxxxxx%xxxxxx%xxxxxxxx%3D%3D"
$payload = #{
"Date" =$Date
"Time" =$Time123
"CPU" = $ComputerCPU
"MEM" = $RoundMemory
}
Invoke-RestMethod -Method Post -Uri "$endpoint" -Body (ConvertTo-Json #($payload))
Write-Host "date: " $Date " time: " $Time123 " cpu: " $ComputerCPU " mem: " $RoundMemory
sleep 0.5
}

Got the way
its through using the OkHTTP.

Building Apache Ftp Server In Android. It is always listing directoring. Need to render html page from Assets

I have built a FTP Server in android app using https://mina.apache.org/ftpserver-project/documentation.html.
I need to render a html page from Assets as my home page. But it is always listing a directory.
connectionConfigFactory.isAnonymousLoginEnabled = true
connectionConfigFactory.maxLogins = 1
connectionConfigFactory.maxThreads = 1
ftpServerFactory.connectionConfig = connectionConfigFactory.createConnectionConfig()
ftpServer = ftpServerFactory.createServer()
listenerFactory.setPort(2121)
ftpServerFactory.addListener("default", listenerFactory.createListener())
ftpServerFactory.ftplets.put(FTPLetImpl::class.java.getName(), FTPLetImpl())
val files =
File(Environment.getExternalStorageDirectory().path + "/users.properties")
if (!files.exists()) {
try {
files.createNewFile()
} catch (e: IOException) {
e.printStackTrace()
}
}
userManagerFactory.setFile(files)
userManagerFactory.setPasswordEncryptor(SaltedPasswordEncryptor())
val um: UserManager = userManagerFactory.createUserManager()
val user = BaseUser()
user.name = "anonymous"
user.enabled = true
val home =
Environment.getExternalStorageDirectory().path + "/Test"
user.homeDirectory = home
val auths: MutableList<Authority> =
ArrayList()
val auth: Authority = WritePermission()
val auth1: Authority = ConcurrentLoginPermission(MAX_CONCURRENT_LOGINS,MAX_CONCURRENT_LOGINS_PER_IP)
val auth2: Authority = TransferRatePermission(Integer.MAX_VALUE, Integer.MAX_VALUE)
auths.add(auth)
auths.add(auth1)
auths.add(auth2)
user.authorities = auths
try {
ftpServerFactory.userManager.save(user)
} catch (e1: FtpException) {
e1.printStackTrace()
}
Even though I set the user home directory as Html page. It gets downloaded in the browser & not rendering it

It's an FTP server. So when an FTP client asks for a directory listing, it gets textual (in case of LIST) or even structured (in case of MLSD) information about files in the directory.
And it's up to the FTP client, how it displays that information to the user. You have no control over that. It's irrelevant that in your particular case, the FTP client is primarily a web browser. In this context, it is not a web browser, it is an FTP client.
If you want to produce an HTML page, you need to implement an HTTP server, not an FTP server.

Android send log lines as an email periodically

I want to send the log lines to email in every 10 minutes.
To do that, I have used a Timer and inside of timer I send the logs via email.
However I loose some log lines between 2 emails.
For example my first email contains no lines which is normal according to my algorithm.
My second email contains log lines between 15.37 and 15.38 seconds.
My third email contains logs in between 15.44 and 15.48 time intervals.
My fourth email contains logs in between 15.55 and 15.58 time intervals.
As you can see I loose some of my logs but I could not find a way to avoid that.
Following is my code in my service class:
#Override
public void onCreate() {
super.onCreate();
mTimer = new Timer();
mTimer.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
sendLogFile();
}
}, 0, 1000 * 60 * 10 );
}
Inside of sendSupport method the second parameter is sent as a content of the log lines where logs is a static string variable.
private void sendLogFile() {
mInteractor.sendSupport("LOG FILE", "MSG"+logs, "SUBJECT"+ System.currentTimeMillis(), "",
result -> {
Timber.log(Log.DEBUG, "sendSupport Thread.currentThread().getName() " + Thread.currentThread().getName());
if (result.isSuccess) {
Timber.d("is sent");
writeLogFile();
} else {
Timber.d("is NOT sent");
}
}
);
}
private void writeLogFile()
{
try {
StringBuilder logBuilder = new StringBuilder();
process = Runtime.getRuntime().exec( "logcat -d");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
String line;
while ((line = bufferedReader.readLine()) != null) {
logBuilder.append(line + "\n");
}
logs = logBuilder.toString();
} catch (IOException e) {
e.printStackTrace();
}
}
As a result I could not figure out how am I going to be able to get all logs in periodically in my email.
Thanks.

While the #Knossos answer is pointing the reason why some logs are missing, it doesn't suggest how to use that knowledge to reliably get the logs from users' phones, when you don't have an access to their devices to run some adb commands.
Here is what I suggest to do instead:
As you do already use Timber, just add some more power to it. Namely, add an additional LoggingTree that will save the logs into a file, instead of just posting them to Logcat. You can have many Timber Trees working simultaneously, so you can have both Logcat and File logs if needed.
Use the same timer to send an email message when and where needed. But, instead of using access to logcat -d, simply use the file where Timber have already written the logs. Don't forget to flush the stream before sending the email. In order not to send the same logs again and again, configure the FileTree in a way that it creates a new file every time when a previous one is sent (seta a new file name via a method call, for example).
Profit :)
To log into two different systems (Trees), you need to simply add one more to Timber:
Timber.plant(new Timber.DebugTree());
Timber.plant(new FileLoggingTree());
And here is an example of FileLoggingTree(source):
public class FileLoggingTree extends Timber.DebugTree {
private static Logger mLogger = LoggerFactory.getLogger(FileLoggingTree.class);
private static final String LOG_PREFIX = "my-log";
public FileLoggingTree(Context context) {
final String logDirectory = context.getFilesDir() + "/logs";
configureLogger(logDirectory);
}
private void configureLogger(String logDirectory) {
// reset the default context (which may already have been initialized)
// since we want to reconfigure it
LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
loggerContext.reset();
RollingFileAppender<ILoggingEvent> rollingFileAppender = new RollingFileAppender<>();
rollingFileAppender.setContext(loggerContext);
rollingFileAppender.setAppend(true);
rollingFileAppender.setFile(logDirectory + "/" + LOG_PREFIX + "-latest.html");
SizeAndTimeBasedFNATP<ILoggingEvent> fileNamingPolicy = new SizeAndTimeBasedFNATP<>();
fileNamingPolicy.setContext(loggerContext);
fileNamingPolicy.setMaxFileSize("1MB");
TimeBasedRollingPolicy<ILoggingEvent> rollingPolicy = new TimeBasedRollingPolicy<>();
rollingPolicy.setContext(loggerContext);
rollingPolicy.setFileNamePattern(logDirectory + "/" + LOG_PREFIX + ".%d{yyyy-MM-dd}.%i.html");
rollingPolicy.setMaxHistory(5);
rollingPolicy.setTimeBasedFileNamingAndTriggeringPolicy(fileNamingPolicy);
rollingPolicy.setParent(rollingFileAppender); // parent and context required!
rollingPolicy.start();
HTMLLayout htmlLayout = new HTMLLayout();
htmlLayout.setContext(loggerContext);
htmlLayout.setPattern("%d{HH:mm:ss.SSS}%level%thread%msg");
htmlLayout.start();
LayoutWrappingEncoder<ILoggingEvent> encoder = new LayoutWrappingEncoder<>();
encoder.setContext(loggerContext);
encoder.setLayout(htmlLayout);
encoder.start();
// Alternative text encoder - very clean pattern, takes up less space
// PatternLayoutEncoder encoder = new PatternLayoutEncoder();
// encoder.setContext(loggerContext);
// encoder.setCharset(Charset.forName("UTF-8"));
// encoder.setPattern("%date %level [%thread] %msg%n");
// encoder.start();
rollingFileAppender.setRollingPolicy(rollingPolicy);
rollingFileAppender.setEncoder(encoder);
rollingFileAppender.start();
// add the newly created appenders to the root logger;
// qualify Logger to disambiguate from org.slf4j.Logger
ch.qos.logback.classic.Logger root = (ch.qos.logback.classic.Logger) LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME);
root.setLevel(Level.DEBUG);
root.addAppender(rollingFileAppender);
// print any status messages (warnings, etc) encountered in logback config
StatusPrinter.print(loggerContext);
}
#Override
protected void log(int priority, String tag, String message, Throwable t) {
if (priority == Log.VERBOSE) {
return;
}
String logMessage = tag + ": " + message;
switch (priority) {
case Log.DEBUG:
mLogger.debug(logMessage);
break;
case Log.INFO:
mLogger.info(logMessage);
break;
case Log.WARN:
mLogger.warn(logMessage);
break;
case Log.ERROR:
mLogger.error(logMessage);
break;
}
}
}

The problem is that logcat -d is only delivering you the latest X bytes of data from the stream. You aren't guaranteed to get everything between 10 minute intervals.
In the best case, you get what you want. In the worst cases, you miss log data or log sections overlap (you get some from the previous dump too).
You can see this here: adb logcat -d | dd
...
03-27 11:36:27.474 791 22420 E ResolverController: No valid NAT64 prefix (147, <unspecified>/0)
03-27 11:36:27.612 3466 3521 I PlayCommon: [657] alsu.c(187): Successfully uploaded logs.
453+111 records in
499+1 records out
255863 bytes (256 kB, 250 KiB) copied, 0,136016 s, 1,9 MB/s
As you can see, it is clearly a 256 kB chunk that is pulled through logcat -d.
On the plus side, you can change that! If you look at adb logcat --help you can see options.
For example, if you use adb logcat -d -t '100000' | dd (all logs in the last 100000 seconds. I now have the following:
...
03-27 11:45:41.687 791 1106 I netd : bandwidthSetGlobalAlert(2097152) <0.90ms>
03-27 11:45:42.098 21897 23376 V FA : Inactivity, disconnecting from the service
2237+1558 records in
2879+1 records out
1474408 bytes (1,5 MB, 1,4 MiB) copied, 1,20785 s, 1,2 MB/s
1.5 MB of logs. You should be able to get all logs with this.
You log the timestamp of each logcat pull, then use that each time to determine the seconds since the last pull.
I hope that helps!

You cannot send an email from the device without user interaction or implementing the email function yourself that allows to do this without user interaction.
Most apps have some api endpoint to send the logs to.

Android's SSLServerSocket causes increasing native memory in the App, OOM

Background
I am developing an Android App which provides a simple HTTP/HTTPS server. If the HTTPS serving is configured then on every connection an increasing native memory usage is observed which eventually leads to an app crash (oom), while using the HTTP configuration keeps the native memory usage relative constant. The app's Java VM keeps relative constant in both configurations.
The app serves an HTML page which contains a javascript with periodic polling (one json poll every second), so calling the app page using the HTTPS configuration and keeping the page open for several hours will lead to the mentioned out-of-memory because of increasing native memory usage. I have tested many SSLServerSocket and SSLContext configurations found on internet with no luck.
I observe the same problem on various Android devices and various Android versions beginning with 2.2 up to 4.3.
The code for handling client requests is the same for both configurations HTTP/HTTPS. The only difference between the two configurations is the setup of the server socket. While in the case of HTTP server socket one single line similar to this "ServerSocket serversocket = new ServerSocket(myport);" does the job, in the case of HTTPS server setup the usual steps for setting up the SSLContext are taken -- i.e. setting up the keymanager and initializing the SSLContext. For now, I use the default TrustManager.
Need For Your Advice
Does somebody know about any memory leak problems in Android's default TLS Provider using OpenSSL? Is there something special I should consider to avoid the leak in the native memory? Any hint is highly appreciated.
Update: I have also tried both TLS providers: OpenSSL and JSSE by explicitly giving the provider name in SSLContext.getInstance( "TLS", providerName ). But that did not change anything.
Here is a code block which demonstrates the problem. Just create a sample app put it into the bottom of the main activity's onCreate and build & run the app. Make sure that your Wifi is on and call the HTML page by following address:
https://android device IP:9090
Then watch the adb logs, after a while you will see the native memory beginning to increase.
new Thread(new Runnable() {
public void run() {
final int PORT = 9090;
SSLContext sslContext = SSLContext.getInstance( "TLS" ); // JSSE and OpenSSL providers behave the same way
KeyManagerFactory kmf = KeyManagerFactory.getInstance( KeyManagerFactory.getDefaultAlgorithm() );
KeyStore ks = KeyStore.getInstance( KeyStore.getDefaultType() );
char[] password = KEYSTORE_PW.toCharArray();
// we assume the keystore is in the app assets
InputStream sslKeyStore = getApplicationContext().getResources().openRawResource( R.raw.keystore );
ks.load( sslKeyStore, null );
sslKeyStore.close();
kmf.init( ks, password );
sslContext.init( kmf.getKeyManagers(), null, new SecureRandom() );
ServerSocketFactory ssf = sslContext.getServerSocketFactory();
sslContext.getServerSessionContext().setSessionTimeout(5);
try {
SSLServerSocket serversocket = ( SSLServerSocket )ssf.createServerSocket(PORT);
// alternatively, the plain server socket can be created here
//ServerSocket serversocket = new ServerSocket(9090);
serversocket.setReceiveBufferSize( 8192 );
int num = 0;
long lastnatmem = 0, natmemtotalincrease = 0;
while (true) {
try {
Socket soc = (Socket) serversocket.accept();
Log.i(TAG, "client connected (" + num++ + ")");
soc.setSoTimeout(2000);
try {
SSLSession session = ((SSLSocket)soc).getSession();
boolean valid = session.isValid();
Log.d(TAG, "session valid: " + valid);
OutputStream os = null;
InputStream is = null;
try {
os = soc.getOutputStream();
// just read the complete request from client
is = soc.getInputStream();
int c = 0;
String itext = "";
while ( (c = is.read() ) > 0 ) {
itext += (char)c;
if (itext.contains("\r\n\r\n")) // end of request detection
break;
}
//Log.e(TAG, " req: " + itext);
} catch (SocketTimeoutException e) {
// this can occasionally happen (handshake timeout)
Log.d(TAG, "socket timeout: " + e.getMessage());
if (os != null)
os.close();
if (is != null)
is.close();
soc.close();
continue;
}
long natmem = Debug.getNativeHeapSize();
long diff = 0;
if (lastnatmem != 0) {
diff = natmem - lastnatmem;
natmemtotalincrease += diff;
}
lastnatmem = natmem;
Log.i(TAG, " answer the request, native memory in use: " + natmem / 1024 + ", diff: " + diff / 1024 + ", total increase: " + natmemtotalincrease / 1024);
String html = "<!DOCTYPE html><html><head>";
html += "<script type='text/javascript'>";
html += "function poll() { request(); window.setTimeout(poll, 1000);}\n";
html += "function request() { var xmlHttp = new XMLHttpRequest(); xmlHttp.open( \"GET\", \"/\", false ); xmlHttp.send( null ); return xmlHttp.responseText; }";
html += "</script>";
html += "</head><body onload=\"poll()\"><p>Refresh the site to see the inreasing native memory when using HTTPS: " + natmem + " </p></body></html> ";
byte[] buffer = html.getBytes("UTF-8");
PrintWriter pw = new PrintWriter( os );
pw.print("HTTP/1.0 200 OK \r\n");
pw.print("Content-Type: text/html\r\n");
pw.print("Content-Length: " + buffer.length + "\r\n");
pw.print("\r\n");
pw.flush();
os.write(buffer);
os.flush();
os.close();
} catch (IOException e) {
e.printStackTrace();
}
soc.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
-- EDIT --
I have uploaded a sample app project called SSLTest for eClipse which demonstrates the problem:
http://code.google.com/p/android/issues/detail?id=59536
-- UPDATE --
Good news: today the reported Android issue above was identified and proper submissions were made to fix the memory leak. For more details see the link above.

I imagine this would be a substantial time investment, but I see that Valgrind has been ported to Android. You could try getting that up and running. Of course, if you find there's an internal memory leak, there isn't a lot you can do about it except attempt to get the bug fixed in future Android releases.
As a workaround, you could make your application multi-process and put the https service in a separate process. That way you could restart it periodically, avoiding OOM. You might also have to have a third process just accepting port 443 connections and passing them on to the https worker - in order to avoid tiny outages when the https worker is restarted.
This also sounds like a substantial time investment :) But it would presumably successfully avoid the problem.
--- EDIT: More detail ---
Yes, if you have a main application with its own UI, a worker process for handling SSL and a worker process for accepting the SSL requests (which as you say probably can't be 443), then on top of your normal Activity classes, you would have two Service classes, and the manifest would place them in separate processes.
Handling SSL process: Rather than waiting for an OOM to crash the service, the service could monitor its own Debug.getNativeHeapSize(), and explicitly restart the service when it increased too much. Either that, or restart automatically after every 100 requests or so.
Handling listening socket process: This service would just listen on the TCP port you choose and pass on the raw data to the SSL process. This bit needs some thought, but the most obvious solution is to just have the SSL process listen on a different local port X (or switch between a selection of different ports), and the listening socket process would forward data to port X. The reason for having the listening socket process is to gracefully handle the possibility that X is down - as it might be whenever you restart it.
If your requirements allow for there being occasional mini-outages I would just do the handling SSL process, and skip the listening socket process, it's a relatively simple solution then - not that different to what you'd do normally. It's the listening socket process that adds complexity to the solution...

Does it help to explicitly close the input stream? In the sample code the input stream seems to only be closed in the case of a SocketTimeoutException exception.
--EDIT--
You could rename run() to run2() and move the while loop into run() and remove it from run2() and see if that makes a difference? This couldn't be a solution but would tell you if any of the long-lived objects free up the memory when their references are dropped.

There is one detail I would recommend changing in your implementation.
Make a list of all your resource variables, for example Sockets, Streams, Writers, etc. Be sure to have the declaration outside your try statement and be sure to do cleanup / closing in the finally statement. I normally do something like this to be 100% sure:
InputStream in = null;
OutputStream out = null;
try {
//assign a proper value to in and out, and use them as needed.
} catch(IOException e) {
//normal error handling
} finally {
try {
in.close();
} catch(IOException e) {}
try {
out.close();
} catch(IOException e) {}
}
It looks a little bit confusing, but imagine you use your in Stream inside the try block and you get some Exception, then your Streams never get closed and that is a potential reason for memory leaks.
I cannot guarantee that this is the reason, but it should be a good startup point.
About managing your service. I had a lot of bad experiences with Android services because I was running them in the same thread as the GUI. Under some circumstances, Android will see some code that is executing for too long and kill your main process in order to protect from crashes. The solution I found was to follow the suggestion from this tutorial (look at point 4):
http://www.vogella.com/articles/AndroidServices/article.html
After this, my service just worked as expected and didn't interfere with my GUI Process.
Regards

Encoding issues using ADB to dispatch messages

I've implemented a service that listens to commands issued through ADB. An example of a command sent through ADB could look like this:
adb shell am startservice -a com.testandroid.SEND_SMS -e number 123123123 -e message "åäö"
Now, the problem here is that the encoding of the string "åäö" seems to mess up. If I take that string extras and immediately output it to the log, I get a square "[]", unknown character. If I send this message I get chinese characters in the messages app. As long as I stick to non-umlaut characters (ASCII I guess), everything works fine.
I'm using Windows 7 and the command line for this. I have not touched the encoding of the command line and I've tried to process the extras string by getting the byte characters, passing in UTF-8 as an encoding argument, then creating a new String passing in UTF-8 as an encoding argument there as well. No dice, though.
The values of the bytes, when using getBytes() are å: -27, ä: -92, ö: -74
How do I get this to play nice so I can make use of at least the umlauts?
All of this works perfectly fine in Linux.

i ran into the same issue, but finally i got it work!
if you use for example C#, you have to do it like the following example:
02.12.2019
According to the protocol.txt, the ADB-Protocol supports "smart-sockets". Those sockets can be used to do all the stuff, the ADB-Client inside the adb.exe does. For example if you want upload an file, you have to request such an "smart-socket". After that, you have to follow the protocol assigned to the service (for an service overview see SERVICE.txt) as described, for example, in the SYNC.txt.
13.10.2014
public static List<string> ExecuteBG(string exe, string args, int timeOut = -1)
{
if (File.Exists(exe) || exe == "cmd.exe")
{
ProcessStartInfo StartInfo = new ProcessStartInfo();
StartInfo.FileName = exe;
StartInfo.Arguments = Encoding.Default.GetString(Encoding.UTF8.GetBytes(args));
StartInfo.CreateNoWindow = true;
StartInfo.UseShellExecute = false;
StartInfo.RedirectStandardError = true;
StartInfo.RedirectStandardOutput = true;
StartInfo.StandardErrorEncoding = Encoding.UTF8;
StartInfo.StandardOutputEncoding = Encoding.UTF8;
AutoResetEvent errorWaitHandle = new AutoResetEvent(false);
AutoResetEvent outputWaitHandle = new AutoResetEvent(false);
List<string> response = new List<string>();
Process proc = new Process();
proc.StartInfo = StartInfo;
proc.ErrorDataReceived += (s, e) =>
{
if (String.IsNullOrEmpty(e.Data))
{
errorWaitHandle.Set();
}
else
{
response.Add(e.Data);
}
};
proc.OutputDataReceived += (s, e) =>
{
if (String.IsNullOrEmpty(e.Data))
{
outputWaitHandle.Set();
}
else
{
response.Add(e.Data);
}
};
proc.Start();
proc.BeginErrorReadLine();
proc.BeginOutputReadLine();
proc.WaitForExit(timeOut);
errorWaitHandle.WaitOne(timeOut);
outputWaitHandle.WaitOne(timeOut);
return response;
}
return new List<string>();
}
Really important is this part "StartInfo.Arguments = Encoding.Default.GetString(Encoding.UTF8.GetBytes(args));", here we convert the UTF8 string into the Windows "default" charset which is known by cmd. So we send a "destroyed" "default" encoded string to cmd and the Android shell will convert it back to UTF8. So we have the "umlauts" like "üöäÜÖÄàè etc.".
Hope this helps someone.
PS: If u need a working "Framework" which supports UTF8 push/pull for files/folders also have a look at my AndroidCtrl.dll it's C# .NET4 written.
Regards,
Sebastian

Concluding, either the problem is situated in cmd.exe or adb.exe. Until either one or both are updated to be more compliant with eachother I will sadly not be able to make use of this for the time being.