Database Users

Problems running Unix commands in native Android Java...

Hello,
I've been trying to do some android stuff on java for some time now, and i've come across a problem here: i can't get the app to execute linux stuff, as there is no system() method like on other platforms... so i searched some code and found this:
Code:
protected void system(String[] Commands){
e Process process = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(process.getOutputStream());
DataInputStream osRes = new DataInputStream(process.getInputStream());
Vector<String> res = new Vector<String>();
for (String single : Commands) {
e os.writeBytes(single + "\n");
e os.flush();
e res.add(osRes.readLine());
// Log.e("CMDs", osRes.readLine());
}
e os.writeBytes("exit\n");
e os.flush();
process.waitFor();
}
However that won't work because of some errors i have in the marked lines:
"Unhandled exception type IOException"
and the process.waitFor(); line also gives me an error:
"Unhandled exception type InterruptedException"
Any ideas?

You need to add a try/catch block around that code which catches the IO exception and the interrupted exception.

deleted

So, first of all thanks to both of you it appears to be working now... i tried in on the emulator, and of course "su" didn't work there (broken pipe), so i replaced it by "sh", however this didn't seem to work well too. the application just locked up with a warning in android.... strange...
edit: tried using /system/bin/sh, didn't work, locked up again

What version of Android in the emulator? I've done it with 1.5 through 2.2 in the emulator, just by using "sh".

could you post the code you used please? would be AWESOME!
i'm trying to get this working on 2.1

Sure, I can post some more details later, but for now just the code.
Include the file in your project and use with:
Code:
ShellCommand cmd = new ShellCommand();
CommandResult r = cmd.sh.runWaitFor("ls -l");
if (!r.success()) {
Log.v(TAG, "Error " + r.stderr);
} else {
Log.v(TAG, "Success! " + r.stdout);
}
If you want su you can either use cmd.shOrSu().runWaitFor("..."); which will try su (by running "id", it just tests the status code but it's a nice entry in logcat for debugging) and fallback to sh. Or you can use cmd.su.runWaitFor("...");
Also at
teslacoilsw.com/files/ShellCommand.java
Code:
package com.teslacoilsw.quicksshd;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import android.util.Log;
public class ShellCommand {
private static final String TAG = "ShellCommand.java";
private Boolean can_su;
public SH sh;
public SH su;
public ShellCommand() {
sh = new SH("sh");
su = new SH("su");
}
public boolean canSU() {
return canSU(false);
}
public boolean canSU(boolean force_check) {
if (can_su == null || force_check) {
CommandResult r = su.runWaitFor("id");
StringBuilder out = new StringBuilder();
if (r.stdout != null)
out.append(r.stdout).append(" ; ");
if (r.stderr != null)
out.append(r.stderr);
Log.v(TAG, "canSU() su[" + r.exit_value + "]: " + out);
can_su = r.success();
}
return can_su;
}
public SH suOrSH() {
return canSU() ? su : sh;
}
public class CommandResult {
public final String stdout;
public final String stderr;
public final Integer exit_value;
CommandResult(Integer exit_value_in, String stdout_in, String stderr_in)
{
exit_value = exit_value_in;
stdout = stdout_in;
stderr = stderr_in;
}
CommandResult(Integer exit_value_in) {
this(exit_value_in, null, null);
}
public boolean success() {
return exit_value != null && exit_value == 0;
}
}
public class SH {
private String SHELL = "sh";
public SH(String SHELL_in) {
SHELL = SHELL_in;
}
public Process run(String s) {
Process process = null;
try {
process = Runtime.getRuntime().exec(SHELL);
DataOutputStream toProcess = new DataOutputStream(process.getOutputStream());
toProcess.writeBytes("exec " + s + "\n");
toProcess.flush();
} catch(Exception e) {
Log.e(QuickSSHD.TAG, "Exception while trying to run: '" + s + "' " + e.getMessage());
process = null;
}
return process;
}
private String getStreamLines(InputStream is) {
String out = null;
StringBuffer buffer = null;
DataInputStream dis = new DataInputStream(is);
try {
if (dis.available() > 0) {
buffer = new StringBuffer(dis.readLine());
while(dis.available() > 0)
buffer.append("\n").append(dis.readLine());
}
dis.close();
} catch (Exception ex) {
Log.e(TAG, ex.getMessage());
}
if (buffer != null)
out = buffer.toString();
return out;
}
public CommandResult runWaitFor(String s) {
Process process = run(s);
Integer exit_value = null;
String stdout = null;
String stderr = null;
if (process != null) {
try {
exit_value = process.waitFor();
stdout = getStreamLines(process.getInputStream());
stderr = getStreamLines(process.getErrorStream());
} catch(InterruptedException e) {
Log.e(TAG, "runWaitFor " + e.toString());
} catch(NullPointerException e) {
Log.e(TAG, "runWaitFor " + e.toString());
}
}
return new CommandResult(exit_value, stdout, stderr);
}
}
}

Thanks kevin The code you are using there is awesome Looking good so far, however it keeps returning permission denied... is it some setting in the android manifest?

Actually "Permission denied" often also means "no such file or directory" on android :-/ . It's very frustrating.
Try running something simple to start with like:
cmd.sh.runWaitFor("echo foo");

[email protected] said:
Actually "Permission denied" often also means "no such file or directory" on android :-/ . It's very frustrating.
Try running something simple to start with like:
cmd.sh.runWaitFor("echo foo");
Click to expand...
Click to collapse
yep, i tried running echo as i was confused by the "permission denied" although i had already set write permissions for the sdcard... didn't work, for some odd reason

[Q] How to read directories?

Hey guys, this is the first time im trying my hand at android development, im still fairly new to development altogether.
Basically what I'm trying to do at the moment is read a list of folder-names in a particular directory, then write those to another file.
The file I'm writing to is at /data/data/com.rone/files/app_list
I'm trying to read from /data/data/
The app has been given su privileges as well. My issue is that I can't seem to read from any folder other than / (root)
Code:
private OnClickListener sort_listener = new OnClickListener() {
@Override
public void onClick(View v) {
String datafolders ="";
File dir = new File("/data/data/");
if(dir.isDirectory() && dir.canRead()){
Log.v("DEBUG", dir.getName() + " is the searching directory!");
for(int i = 0; i < dir.list().length; i++) {
datafolders += dir.list()[i] + " \n";
}
}
else {
Log.v("ERROR", "directory does not exist or can not be accessed!");
}
writeFile(datafolders, "app_list");
}
};
public void writeFile(String input, String filename) {
try {
FileOutputStream fos = openFileOutput(filename, Context.MODE_PRIVATE);
fos.write(input.getBytes());
fos.close();
return;
} catch (FileNotFoundException e) {
Log.v("ERROR", e.getMessage());
} catch (IOException e) {
Log.v("ERROR", e.getMessage());
}
}
public String readFile(String filename) {
try {
FileInputStream fis = openFileInput(filename);
String temp = "";
int ch;
while ((ch = fis.read()) > -1) {
temp += (char) ch;
}
fis.close();
return temp;
} catch (FileNotFoundException e) {
Log.v("ERROR", e.getMessage());
return "Exception" + e;
} catch (IOException e) {
Log.v("ERROR", e.getMessage());
return "Exception" + e;
}
}
It only writes to the file when I use:
Code:
File dir = new File("./");
Also, my app is specifically written for the SGS and I'm using Eclipse. Any way to get and import a custom SGS skin with the Menu and Back button functionality?

No replies? No one knows how to read the directories? Is there a limitation built-in that stops from reading directories? Even with su permissions?

[Q] Can I register a listener on process state?

I'm an experienced developer but new to Android development. I have an app that runs some native binaries, and I provide a status indicator to show when the native process is running and when it's not. Currently I poll the device to figure this out, using the ActivityManager API to determine if specific processes are running or not.
I'm hoping there is some way to register a listener on process state changes, so I can get notified when my process starts or stops. I looked through the API, and there doesn't seem to be such a thing. Does anyone know how I can keep track of process start and stop other than polling via ActivityManager?

MidnightJava said:
I'm an experienced developer but new to Android development. I have an app that runs some native binaries, and I provide a status indicator to show when the native process is running and when it's not. Currently I poll the device to figure this out, using the ActivityManager API to determine if specific processes are running or not.
I'm hoping there is some way to register a listener on process state changes, so I can get notified when my process starts or stops. I looked through the API, and there doesn't seem to be such a thing. Does anyone know how I can keep track of process start and stop other than polling via ActivityManager?
Click to expand...
Click to collapse
Afaik there's no way to accomplish that other than your way or being system/root app. See this similar question here for reference.

Can you show how you start the process?

EmptinessFiller said:
Can you show how you start the process?
Click to expand...
Click to collapse
Sure. Here's the class that manages starting, stopping, and statusing (running or not) the binary executable. In this case, it's the omniNames service of the omni ORB (CORBA broker).
Code:
public class RHManager {
private TimerTask task = new TimerTask() {
@Override
public void run() {
if (RHManager.this.listener != null) {
listener.running(isOmniNamesRunning());
}
}
};
private IStatusListener listener;
public RHManager() {
}
public void startOmniNames() {
final Exec exec = new Exec();
final String[] args = new String[]
{RhMgrConstants.INSTALL_LOCATION_OMNI_NAMES_SCRIPTS + "/" + RhMgrConstants.OMNI_NAMES_SCRIPT_FILE,
"start"};
final String[] env = new String[] {"LD_LIBRARY_PATH=/sdcard/data/com.axiosengineering.rhmanager/omniORB/lib"};
Thread t = new Thread() {
public void run() {
try {
int res = exec.doExec(args, env);
logMsg("omniNames start return code " + res);
} catch (IOException e) {
logMsg("Failed to start omniNames");
e.printStackTrace();
}
String std = exec.getOutResult();
logMsg("omniNames start: std out==> " + std );
String err = exec.getErrResult();
logMsg("omniNames start: err out==> " + err );
};
};
t.start();
logMsg("omniNames started");
}
private boolean isOmniNamesRunning() {
String pid_s = getOmniNamesPid();
Integer pid = null;
if (pid_s != null) {
try {
pid = Integer.parseInt(pid_s);
} catch (NumberFormatException e) {
return false;
}
}
if (pid != null) {
RunningAppProcessInfo activityMgr = new ActivityManager.RunningAppProcessInfo("omniNames", pid, null);
return activityMgr.processName != null ;
}
return false;
}
public void stopOmniNames() {
String pid = getOmniNamesPid();
android.os.Process.killProcess(Integer.parseInt(pid));
android.os.Process.sendSignal(Integer.parseInt(pid), android.os.Process.SIGNAL_KILL);
}
private String getOmniNamesPid() {
Exec exec = new Exec();
final String[] args = new String[]
{RhMgrConstants.INSTALL_LOCATION_OMNI_NAMES_SCRIPTS + "/" + RhMgrConstants.OMNI_NAMES_SCRIPT_FILE,
"pid"};
String pid = "";
try {
int res = exec.doExec(args, null);
logMsg("oniNames pid return code: " + res);
} catch (IOException e) {
logMsg("Failed to start omniNames");
e.printStackTrace();
return pid;
}
String std = exec.getOutResult();
logMsg("omniNames pid: std out ==> " + std);
String err = exec.getErrResult();
logMsg("omniNames pid: err out ==> " + err);
String[] parts = std.split("\\s+");
if (parts.length >= 2) {
pid = parts[1];
}
return pid;
}
//monitor omniNames status and report status periodically to an IStatusListener
public void startMonitorProcess(IStatusListener listener, String string) {
this.listener = listener;
Timer t = new Timer();
t.schedule(task, 0, 1000);
}
private void logMsg(String msg) {
if (RhMgrConstants.DEBUG) {
System.err.println(msg);
}
}
}
Here's the Exec class that handles invocation of Runtime#exec(), consumes std and err out, and reports those and process return status to the caller.
Code:
public class Exec {
private String outResult;
private String errResult;
private Process process;
private boolean failed = false;
StreamReader outReader;
StreamReader errReader;
public int doExec(String[] cmd, String[] envp) throws IOException{
Timer t = null;
try {
process = Runtime.getRuntime().exec(cmd, envp);
outReader = new StreamReader(process.getInputStream());
outReader.setPriority(10);
errReader = new StreamReader(process.getErrorStream());
outReader.start();
errReader.start();
t = new Timer();
t.schedule(task, 10000);
int status = process.waitFor();
outReader.join();
errReader.join();
StringWriter outWriter = outReader.getResult();
outResult = outWriter.toString();
outWriter.close();
StringWriter errWriter = errReader.getResult();
errResult = errWriter.toString();
errWriter.close();
return (failed ? -1: status);
} catch (InterruptedException e) {
return -1;
} finally {
if (t != null) {
t.cancel();
}
}
}
public int doExec(String[] cmd) throws IOException{
return doExec(cmd, null);
}
public String getOutResult(){
return outResult;
}
public String getErrResult(){
return errResult;
}
private static class StreamReader extends Thread {
private InputStream is;
private StringWriter sw;
StreamReader(InputStream is) {
this.is = is;
sw = new StringWriter(30000);
}
public void run() {
try {
int c;
while ((c = is.read()) != -1){
sw.write(c);
}
}
catch (IOException e) { ; }
}
StringWriter getResult() {
try {
is.close();
} catch (IOException e) {
System.err.println("Unable to close input stream in StreamReader");
}
return sw;
}
}
private TimerTask task = new TimerTask() {
@Override
public void run() {
failed = true;
process.destroy();
}
};
}
Here's the script that startOminNames() invokes. It's the shell script installed with omniORB with functions other than start and get_pid removed, since those are handled by Android classes. You can invoke any executable in place of the script, or wrap your executable in a script.
Code:
#
# omniNames init file for starting up the OMNI Naming service
#
# chkconfig: - 20 80
# description: Starts and stops the OMNI Naming service
#
exec="/sdcard/data/com.axiosengineering.rhmanager/omniORB/bin/omniNames"
prog="omniNames"
logdir="/sdcard/data/com.axiosengineering.rhmanager/omniORB/logs"
logfile="/sdcard/data/com.axiosengineering.rhmanager/omniORB/logs/omninames-localhost.err.log"
options=" -start -always -logdir $logdir -errlog $logfile"
start() {
#[ -x $exec ] || exit 5
echo -n $"Starting $prog: "
$exec $options
}
get_pid() {
ps | grep omniNames
}
case "$1" in
start)
start && exit 0
$1
;;
pid)
get_pid
;;
*)
echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
exit 2
esac
exit $?
And here's the IStatusListener interface
Code:
public interface IStatusListener {
public void running(boolean running);
}
Runtime.exec() has some pitfalls. See this helpful Runtime.exec tutorial for a nice explanation.
And you may also want to check out this post on loading native binaries in Android.

[Q] Google Drive android api - Downloading sqlite db file from drive

I am using the below code for downloading an already uploaded sqlite db file from google drive to the data/data/packagename/databases folder, but when the method completes, I am seeing a db corruption warning message logged in logcat and also all the data on the device for the app is overwritten and shows up blank, upon opening the app.
Code:
mfile = Drive.DriveApi.getFile(mGoogleApiClient, mResultsAdapter.getItem(0).getDriveId());
mfile.openContents(mGoogleApiClient, DriveFile.MODE_READ_ONLY, null).setResultCallback(contentsOpenedCallback);
--mfile is an instance of DriveFile
final private ResultCallback<ContentsResult> contentsOpenedCallback = new ResultCallback<ContentsResult>()
{
@Override
public void onResult(ContentsResult result)
{
if (!result.getStatus().isSuccess())
{
FileUtils.appendLog(getApplicationContext(), Tag + "-onResult", "Error opening file");
return;
}
try
{
if (GetFileFromDrive(result))
{
//FileUtils.Restore(getApplicationContext());
SharedPrefHelper.EditSharedPreference(getApplicationContext(), Constants.PREFS_DO_RESTORE, false);
}
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
private boolean GetFileFromDrive(ContentsResult result)
{
Contents contents = result.getContents();
//InputStreamReader rda = new InputStreamReader(contents.getInputStream());
BufferedReader reader = new BufferedReader(new InputStreamReader(contents.getInputStream()));
FileOutputStream outStream;
String currLine;
boolean restoreSuccess = false;
File sourceDbFile = BackupDBBeforeDeletion();
if(sourceDbFile != null)
sourceDbFile.delete();
try
{
outStream = new FileOutputStream(getApplicationContext().getDatabasePath(Constants.DB_NAME));
while ((currLine = reader.readLine()) != null)
{
outStream.write(currLine.getBytes());
}
outStream.flush();
reader.close();
outStream.close();
restoreSuccess = true;
}
catch (FileNotFoundException e)
{
// TODO: Log exception
}
catch (IOException e)
{
// TODO: Log Exception
}
return restoreSuccess;
}
When the method GetFileFromDrive completes, a db corruption shows up on LogCat and all the existing data on the app's datanase file (sqlite db) is gone.
Please help, as I have verified that the drive uploaded sqlite db file is correct and well formed, by downloading the same and opening it up in Sqlite Browser. It's the download from drive that is not working.

Camera2 focus state during preview

Hi,
I have built a small notepad+barcodescanner app. Not it works, but the performance is low, as it processes all frames. It would be good if it would process only frams which are captured when the focus settled.
The app uses Camera2 PreviewBulder and CaptureRequestBuilder / RepeatingRequest, but i only found ways to get focus state during a Capturesession. (Capture is not used in this app, only getting frames from preview).
Does anyone how to process the focus state if one uses a Preview...?
Thanks for any help
Corresponding code part:
private final CameraDevice.StateCallback stateCallback = new
CameraDevice.StateCallback() {
@override
public void onOpened(CameraDevice camera) {
//This is called when the camera is open
// Log.e(TAG, "onOpened");
cameraDevice = camera;
createCameraPreview();
}
@override
public void onDisconnected(CameraDevice camera) {
cameraDevice.close();
}
@override
public void onError(CameraDevice camera, int error) {
cameraDevice.close();
cameraDevice = null;
}
};
final CameraCaptureSession.CaptureCallback captureCallbackListener = new CameraCaptureSession.CaptureCallback() {
@override
public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
// makeText(MainActivity.this, "Saved:" + file, LENGTH_SHORT).show();
createCameraPreview();
}
};
protected void startBackgroundThread() {
mBackgroundThread = new HandlerThread("Camera Background");
mBackgroundThread.start();
mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
}
protected void stopBackgroundThread() {
mBackgroundThread.quitSafely();
try {
mBackgroundThread.join();
mBackgroundThread = null;
mBackgroundHandler = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
protected void createCameraPreview() {
try {
SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(imageDimension.getWidth(),
imageDimension.getHeight());
Surface surface = new Surface(texture);
CameraManager manager;
manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
String camerId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(camerId);
boolean aelockavailable = characteristics.get(CameraCharacteristics.CONTROL_AE_LOCK_AVAILABLE);
}catch (Exception e)
{
}
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, captureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
//captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, captureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
captureRequestBuilder.addTarget(surface);
cameraDevice.createCaptureSession(Arrays.asList(surface),
new CameraCaptureSession.StateCallback() {
@override
public void onConfigured(@NonNull CameraCaptureSession
cameraCaptureSession) {
//The camera is already closed
if (null == cameraDevice) {
return;
}
// When the session is ready, we start displaying the preview.
cameraCaptureSessions = cameraCaptureSession;
updatePreview();
}
@override
public void onConfigureFailed(@NonNull
CameraCaptureSession cameraCaptureSession) {
//makeText(MainActivity.this, "Configuration change", LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
void openCamera() {
CameraManager manager = (CameraManager)
getSystemService(Context.CAMERA_SERVICE);
//Log.e(TAG, "is camera open");
try {
cameraId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics =
manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map =
characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
// Add permission for camera and let user grant the permission
if (ActivityCompat.checkSelfPermission(this,
Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED &&
ActivityCompat.checkSelfPermission(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE) !=
PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.CAMERA,
Manifest.permission.WRITE_EXTERNAL_STORAGE},
REQUEST_CAMERA_PERMISSION);
return;
}
manager.openCamera(cameraId, stateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
//Log.e(TAG, "openCamera X");
}
void updatePreview() {
if (null == cameraDevice) {
//Log.e(TAG, "updatePreview error, return");
}
captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, captureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
//captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
if (flashchanged) {flashchanged=false; if (lamp && autoflash) {captureRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_TORCH);} else {captureRequestBuilder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_OFF);} }
try {
cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(),
null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void closeCamera() {
if (null != cameraDevice) {
cameraDevice.close();
cameraDevice = null;
}
if (null != imageReader) {
imageReader.close();
imageReader = null;
}
}