Logcat prints a single line with just the message and no exception stack trace. I am passing the exception e to the Log.i function. It used to work before. Now I can only see the stack trace using e.printStackTrace() which prints it to system.err.
catch (final IOException e) {
Log.i(TAG, "Error connecting to server.", e);
}
I think it may be because my current project is an Android Library and not an Application.
It's supposed to look like this but instead I only get the very first line. In my case it says "Error connecting to server." in place of "FATAL EXCEPTION: main".
Related
Preface I've changed the title. It is hard to understand why, while debugging, sometimes uncaught exceptions print 'FATAL EXCEPTION' to the Logcat and sometimes they don't.
The simplified example below crashes when I get to the line client1.getInputStream(). There is no stack trace or other indication inside of Logcat as to what went wrong. I am running Android Studio 3.0.0beta4.
Why is it crashing? (update - crash was due to a SecurityException)
And why does Logcat not show a stack trace or
other error?
Update
Okay, I figured out why it crashes. I added catch(Exception ex) {...} and found that an exception was in fact being thrown, for I had forgotten to test for it. Stupid error, I didn't include INTERNET permission in the manifest.
So, I would still like to know why I would get no error indication for the unhandle exception. The app just quietly disappears.
Edit One commenter says
In java, unhandled exceptions are not printed
Here is the logcat message when I force an unhandled NullPointerException
FATAL EXCEPTION: Thread-6729
Process: com.example.myapplication, PID: 30824
java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.InputStream java.net.URLConnection.getInputStream()' on a null object reference
at com.example.myapplication.MainActivity.GetDataAsyncFromPlaystore(MainActivity.java:79)
at com.example.myapplication.MainActivity$1$1.run(MainActivity.java:42)
at java.lang.Thread.run(Thread.java:818)
So, why not for SecurityException?
Edit2 Just to make things more confusing, I've discovered that when I set a break point prior to the exception point, then step through the code and step over the offending line (the one causing the SecurityException), the App abruptly terminates with with no indication as to why. If however, I hit F9 before reaching the offending line, I do, in fact, get a "FATAL EXCEPTION" message logged in Logcat. (Therefore, I've added back the "android-studio" tag to the question.)
So, same question, slightly different wording: Why does the exception print a 'FATAL EXCEPTION' message when debugging one way, but not the other?
The (simplified) code
public void GetDataFromWebsite()
{
Uri queryUri = Uri.parse("https://play.google.com/store/search?q=Planning&c=apps");
try {
URL queryUrl = new URL(queryUri.toString());
URLConnection client1 = queryUrl.openConnection();
InputStream in = client1.getInputStream();
Log.d("Test", "Okay");
} catch (MalformedURLException muex) {
Log.e("Test", "Malformed Url", muex);
} catch (IOException ioex) {
Log.e("Test", "IO Error", ioex);
// } catch(Exception ex) {
// Log.e("Test","Other Exception", ex);
}
}
NOTE:
You are just catching MalformedURLException and IOException. So you won't get other exceptions.
Catch with Exception you will get a trace.
UnHandled exception not printed in android log cat. you can print UnHandled exception by UncaughtExceptionHandler. Here is a like to implement UncaughtExceptionHandler: Logging unhandled exceptions in Android Activity
There is no relativity between NullpointerException and SecurityException. How it will get caught by SecurityException.
Calling Log.e(TAG, "some message", e) where e is an UnknownHostException, does not print the stack trace on the logcat.
Since May 20, 2011, there is a change in the Log class, such that UnknownHostException exceptions are not printed.
This is to reduce the amount of log spew that apps do in the non-error
condition of the network being unavailable.
https://github.com/android/platform_frameworks_base/commit/dba50c7ed24e05ff349a94b8c4a6d9bb9050973b
The e you are including is useless, remove it and it would be visible in logcat.
Log.e(TAG, "some message");
Hello everybody I am new of Eclipse and Java. I want to see the stack trace of a ClassNotFoundException but I cannot see it on LogCat.
I tried all the possible output here in the code that I cannot see absolutely nothing in the logcat.
try{
Class.forName("com.mysql.jdbc.Driver");
}
catch(ClassNotFoundException e){
e.printStackTrace();
Log.d("appcani","I am here");
Log.d("YOUR_APP_LOG_TAG", "I got an error", e);
}
It seems it doesn't go inside the catch but without the catch it gives the ClassNotFoundException so it should go inside the catch.
I already tried to use:
catch(Exception e)
but it doesn't work as well
Is it possible to get variable values included in a stack trace? I have just started using bugsense which emails the stacktrace to me and I wonder if there is some way in my code to put the variable values into the stacktrace output
Not by default, you have to do it by yourself:
The stack trace will only tell you about the involved line of code (where the Exception is thrown) and the execution stack.
But nothing prevents you from catching the Exception and to include some debug information in the message:
try {
...the code...
}
catch (Throwable t) {
// Here, we catch any Throwable (Exception but also Error such as OutOfMemory
// or NoClassDefFound), which is *absolutely not suitable* for
// anything else than debugging.
// You can (should, actually) make this catch statement more specific
// depending of the Exception or Error you are facing
// Dump your variables here:
final String message = "myVar=" + myVar;
// The statement below rethrows the original Throwable and adds your
// own message to it
throw new RuntimeException(message, t);
}
Or to put a breakpoint in the catch { } statement to inspect the state of your application at that stage, but as I understood it may not be applicable in the case you are describing.
(By the way, I suggest you add the tag "Java" to your question. This way it will also be visible by the Java community of StackOverflow)
I want to catch an IOException Error and want to show it in the form of toast for android application development. But when ever i apply catch(IOexception e), after try block it says to throws (throws IOException) with function name after which i am to catch error message.. Please Provide Some assistance....
May be you desire to 'throws' catched exception above the call stack, and next, catch and process all exception in one place (or 'layer') of code?)