How can I get crash data (stack traces at least) from my Android application? At least when working on my own device being retrieved by cable, but ideally from any instance of my application running on the wild so that I can improve it and make it more solid.
30 Answers
For sample applications and debugging purposes, I use a simple solution that allows me to write the stacktrace to the sd card of the device and/or upload it to a server. This solution has been inspired by Project android-remote-stacktrace (specifically, the save-to-device and upload-to-server parts) and I think it solves the problem mentioned by Soonil. It's not optimal, but it works and you can improve it if you want to use it in a production application. If you decide to upload the stacktraces to the server, you can use a php script (index.php) to view them. If you're interested, you can find all the sources below - one java class for your application and two optional php scrips for the server hosting the uploaded stacktraces.
In a Context (e.g. the main Activity), call
if(!(Thread.getDefaultUncaughtExceptionHandler() instanceof CustomExceptionHandler)) {
Thread.setDefaultUncaughtExceptionHandler(new CustomExceptionHandler(
"/sdcard/<desired_local_path>", "http://<desired_url>/upload.php"));
}
CustomExceptionHandler
public class CustomExceptionHandler implements UncaughtExceptionHandler {
private UncaughtExceptionHandler defaultUEH;
private String localPath;
private String url;
/*
* if any of the parameters is null, the respective functionality
* will not be used
*/
public CustomExceptionHandler(String localPath, String url) {
this.localPath = localPath;
this.url = url;
this.defaultUEH = Thread.getDefaultUncaughtExceptionHandler();
}
public void uncaughtException(Thread t, Throwable e) {
String timestamp = TimestampFormatter.getInstance().getTimestamp();
final Writer result = new StringWriter();
final PrintWriter printWriter = new PrintWriter(result);
e.printStackTrace(printWriter);
String stacktrace = result.toString();
printWriter.close();
String filename = timestamp + ".stacktrace";
if (localPath != null) {
writeToFile(stacktrace, filename);
}
if (url != null) {
sendToServer(stacktrace, filename);
}
defaultUEH.uncaughtException(t, e);
}
private void writeToFile(String stacktrace, String filename) {
try {
BufferedWriter bos = new BufferedWriter(new FileWriter(
localPath + "/" + filename));
bos.write(stacktrace);
bos.flush();
bos.close();
} catch (Exception e) {
e.printStackTrace();
}
}
private void sendToServer(String stacktrace, String filename) {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
List<NameValuePair> nvps = new ArrayList<NameValuePair>();
nvps.add(new BasicNameValuePair("filename", filename));
nvps.add(new BasicNameValuePair("stacktrace", stacktrace));
try {
httpPost.setEntity(
new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
httpClient.execute(httpPost);
} catch (IOException e) {
e.printStackTrace();
}
}
}
upload.php
<?php
$filename = isset($_POST['filename']) ? $_POST['filename'] : "";
$message = isset($_POST['stacktrace']) ? $_POST['stacktrace'] : "";
if (!ereg('^[-a-zA-Z0-9_. ]+$', $filename) || $message == ""){
die("This script is used to log debug data. Please send the "
. "logging message and a filename as POST variables.");
}
file_put_contents($filename, $message . "\n", FILE_APPEND);
?>
index.php
<?php
$myDirectory = opendir(".");
while($entryName = readdir($myDirectory)) {
$dirArray[] = $entryName;
}
closedir($myDirectory);
$indexCount = count($dirArray);
sort($dirArray);
print("<TABLE border=1 cellpadding=5 cellspacing=0 \n");
print("<TR><TH>Filename</TH><TH>Filetype</th><th>Filesize</TH></TR>\n");
for($index=0; $index < $indexCount; $index++) {
if ((substr("$dirArray[$index]", 0, 1) != ".")
&& (strrpos("$dirArray[$index]", ".stacktrace") != false)){
print("<TR><TD>");
print("<a href=\"$dirArray[$index]\">$dirArray[$index]</a>");
print("</TD><TD>");
print(filetype($dirArray[$index]));
print("</TD><TD>");
print(filesize($dirArray[$index]));
print("</TD></TR>\n");
}
}
print("</TABLE>\n");
?>
It is possible to handle these exceptions with Thread.setDefaultUncaughtExceptionHandler(), however this appears to mess with Android's method of handling exceptions. I attempted to use a handler of this nature:
private class ExceptionHandler implements Thread.UncaughtExceptionHandler {
@Override
public void uncaughtException(Thread thread, Throwable ex){
Log.e(Constants.TAG, "uncaught_exception_handler: uncaught exception in thread " + thread.getName(), ex);
//hack to rethrow unchecked exceptions
if(ex instanceof RuntimeException)
throw (RuntimeException)ex;
if(ex instanceof Error)
throw (Error)ex;
//this should really never happen
Log.e(Constants.TAG, "uncaught_exception handler: unable to rethrow checked exception");
}
}
However, even with rethrowing the exceptions, I was unable to get the desired behavior, ie logging the exception while still allowing Android to shutdown the component it had happened it, so I gave up on it after a while.
Ok, well I looked at the provided samples from rrainn and Soonil, and I found a solution that does not mess up error handling.
I modified the CustomExceptionHandler so it stores the original UncaughtExceptionHandler from the Thread we associate the new one. At the end of the new "uncaughtException"- Method I just call the old function using the stored UncaughtExceptionHandler.
In the DefaultExceptionHandler class you need sth. like this:
public class DefaultExceptionHandler implements UncaughtExceptionHandler{
private UncaughtExceptionHandler mDefaultExceptionHandler;
//constructor
public DefaultExceptionHandler(UncaughtExceptionHandler pDefaultExceptionHandler)
{
mDefaultExceptionHandler= pDefaultExceptionHandler;
}
public void uncaughtException(Thread t, Throwable e) {
//do some action like writing to file or upload somewhere
//call original handler
mStandardEH.uncaughtException(t, e);
// cleanup, don't know if really required
t.getThreadGroup().destroy();
}
}
With that modification on the code at http://code.google.com/p/android-remote-stacktrace you have a good working base for logging in the field to your webserver or to sd-card.
I made my own version here : http://androidblogger.blogspot.com/2009/12/how-to-improve-your-application-crash.html
It's basically the same thing, but I'm using a mail rather than a http connexion to send the report, and, more important, I added some informations like application version, OS version, Phone model, or avalaible memory to my report...
For an alternate crash reporting/exception tracking service check out Raygun.io - it's got a bunch of nice logic for handling Android crashes, including decent user experience when plugging it in to your app (two lines of code in your main Activity and a few lines of XML pasted into AndroidManifest).
When your app crashes, it'll automatically grab the stack trace, environment data for hard/software, user tracking info, any custom data you specify etc. It posts it to the API asynchronously so no blocking of the UI thread, and caches it to disk if there's no network available.
Disclaimer: I built the Android provider :)
Flurry analytics gives you crash info, hardware model, android version and live app usage stats. In the new SDK they seem to provide more detailed crash info http://www.flurry.com/flurry-crash-analytics.html.
You can do this directly in Android Studio. Just connect your phone, run the app, let it crash and you can view the stacktrace directly in Android Studio.
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