Android - print full exception backtrace to log
AndroidAndroid Problem Overview
I have a try/catch block that throws an exception and I would like to see information about the exception in the Android device log.
I read the log of the mobile device with this command from my development computer:
/home/dan/android-sdk-linux_x86/tools/adb shell logcat
I tried this first:
try {
// code buggy code
} catch (Exception e)
{
e.printStackTrace();
}
but that doesn't print anything to the log. That's a pity because it would have helped a lot.
The best I have achieved is:
try {
// code buggy code
} catch (Exception e)
{
Log.e("MYAPP", "exception: " + e.getMessage());
Log.e("MYAPP", "exception: " + e.toString());
}
Better than nothing but not very satisfying.
Do you know how to print the full backtrace to the log?
Thanks.
Android Solutions
Solution 1 - Android
try {
// code that might throw an exception
} catch (Exception e) {
Log.e("MYAPP", "exception", e);
}
More Explicitly with Further Info
(Since this is the oldest question about this.)
The three-argument Android log methods will print the stack trace for an Exception
that is provided as the third parameter. For example
Log.d(String tag, String msg, Throwable tr)
where tr
is the Exception.
According to this comment those Log methods "use the getStackTraceString()
method ... behind the scenes" to do that.
Solution 2 - Android
This helper function also works nice since Exception is also a Throwable.
try{
//bugtastic code here
}
catch (Exception e)
{
Log.e(TAG, "Exception: "+Log.getStackTraceString(e));
}
Solution 3 - Android
catch (Exception e) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream stream = new PrintStream( baos );
e.printStackTrace(stream);
stream.flush();
Log.e("MYAPP", new String( baos.toByteArray() );
}
Or... ya know... what EboMike said.
Solution 4 - Android
public String getStackTrace(Exception e){
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
return sw.toString();
}
Solution 5 - Android
e.printStackTrace() prints it to me. I don't think you're running the logcat correctly. Don't run it in a shell, just run
/home/dan/android-sdk-linux_x86/tools/adb logcat
Solution 6 - Android
The standard output and error output are directed to /dev/null by default so it is all lost. If you want to log this output then you need to follow the instructions "Viewing stdout and stderr" shown here
Solution 7 - Android
try{
...
} catch (Exception e) {
Log.e(e.getClass().getName(), e.getMessage(), e.getCause());
}
Solution 8 - Android
In the context of Android, I had to cast the Exception to a String:
try {
url = new URL(REGISTRATION_PATH);
urlConnection = (HttpURLConnection) url.openConnection();
} catch(MalformedURLException e) {
Log.i("MALFORMED URL", String.valueOf(e));
} catch(IOException e) {
Log.i("IOException", String.valueOf(e));
}
Solution 9 - Android
KOTLIN SOLUTION:
You can make use of the helper function getStackTraceString()
belonging to the android.util.Log
class to print the entire error message on console.
Example:
try {
// your code here
} catch (e: Exception) {
Log.e("TAG", "Exception occurred, stack trace: " + e.getStackTraceString());
}
Solution 10 - Android
Kotlin extension. Returns the detailed description of this throwable with its stack trace.
e.stackTraceToString()