Initialising ChoiceGroup + J2ME MIDlet - java-me

I have XML being parsed into a custom blogger class array, with this I am trying to show on screen a ChoiceGroup of the .name attribute of my blogger class.
for(int i = 0; i< intBloggerLength; i++)
{
menuItems[i] = myXMLParser.arrBloggers[i].getName();
//lstView.append(myXMLParser.arrBloggers[i].getName().toString(), null);
}
String strPause = "";
grpMenuItems = new ChoiceGroup("Bloggers", Choice.IMPLICIT, menuItems,
new Image[] {null, null, null, null, null, null});
"grpMenuItems =..." is the line that is erroring, and making my MIDlet crash, I have been following examples online and I am populating the ChoiceGroup the same way, does anyone have any ideas?

The issue was me using a Choice.IMPLICIT which does not exist for ChoiceGroup, but for List.
Changing for Choice.EXCLUSIVE works fine.

Your main mistake here is I think not using appropriate logging in your MIDlet. That makes debugging of the issues like you describe unnecessary complicated. mistakes in the code snippet you posted.
With logging done right (refer here for details if you're interested), you could simply run your midlet in emulator and check console messages to find out whether expected code.
From the code snippet you posted and your explanations it looks like intBloggerLength value is not constant. Coupled with the way how you invoke ChoiceGroup constructor in the line you mention as problematic, this looks a sure way to get IllegalArgumentException.
You could find that out yourself if you'd wrap this line into try-catch and put appropriate logging code into catch block but since you didn't do that, we have to merely guess. Note if you test in emulator, there is also a chance for exception message and stack trace to be shown in its console.
To find out how you could get that exception, refer to API javadocs for the constructor you use:
Throws:
...IllegalArgumentException - if the imageElements array is non-null and has a different length from the stringElements array...
There are three other possible reasons for exception to be thrown listed in API docs, but I'll focus on one where your code snippet looks very slippery.
Let's look back at your code, images array length is 6: {null, null, null, null, null, null} - this means as soon as intBloggerLength differs from 6, this will throw IAE.
To fix this, simplest way would be to pass null value instead of images array. Or, if you need the array to be not null, just write the code so that it has valid length, eg
new Image[menuItems.length]

Related

UWP Windows 10 app crashes in release mode but works fine in debug mode

My UWP app is crashing in Release mode and works fine in Debug mode but I can't put my finger on what the issue is but I know it's related to a combination of raising an event from System.Threading.Timer and MVVMLight.
I created an new dummy application and use the same code (ZXing.net.mobile where I used 2 portable libraries and I used my own user control which is a simplified version of theirs - I'm using events instead of <Action>). This works fine and I'm currently trying to put more steps into it i.e. include mvvmlight and navigation but so far, I can't reproduce the problem in this dummy app.
The error I'm getting is:
Unhandled exception at 0x58C1AF0B (mrt100_app.dll) in Company.MyApp.App.exe:
0xC0000602: A fail fast exception occurred. Exception handlers will not be
invoked and the process will be terminated immediately.
Followed by:
Unhandled exception at 0x0107D201 (SharedLibrary.dll) in
Company.MyApp.App.exe: 0x00001007.
When looking at the Threads window, one of the worker thread has the following information if that's of help.
Not Flagged > 4012 0 Worker Thread <No Name>
System.Private.Interop.dll!System.Runtime.InteropServices.
ExceptionHelpers.ReportUnhandledError Normal
[External Code]
System.Private.Interop.dll!System.Runtime.InteropServices.ExceptionHelpers.
ReportUnhandledError(System.Exception e) Line 885
System.Private.Interop.dll!Internal.Interop.InteropCallbacks.ReportUnhandledError
(System.Exception ex) Line 17
System.Private.WinRTInterop.CoreLib.dll!Internal.WinRT.Interop.WinRTCallbacks.
ReportUnhandledError(System.Exception ex) Line 274
System.Private.CoreLib.dll!System.RuntimeExceptionHelpers.ReportUnhandledException
(System.Exception exception) Line 152
System.Private.Threading.dll!System.Threading.Tasks.AwaitTaskContinuation.
ThrowAsyncIfNecessary(System.Exception exc) Line 784
System.Private.Threading.dll!System.Threading.WinRTSynchronizationContext.Invoker.
InvokeCore() Line 182
System.Private.Threading.dll!System.Threading.WinRTSynchronizationContext.Invoker.
Invoke(object thisObj) Line 162
System.Private.CoreLib.dll!System.Action<System.__Canon>.
InvokeOpenStaticThunk(System.__Canon obj)
System.Private.WinRTInterop.CoreLib.dll!Internal.WinRT.Interop.WinRTCallbacks.PostToCoreDispatcher.AnonymousMethod__0() Line 266
MyCompany.MyApp.App.exe
MyCompany.MyApp.App.ViewModels.ValidateHandler.Invoke(string pin)
MyCompany.MyApp.App.McgInterop.dll!McgInterop.ReverseComSharedStubs
.Proc_(object __this, System.IntPtr __methodPtr) Line 6163
MyCompany.MyApp.App.McgInterop.dll!Windows.UI.Core.DispatchedHandler__Impl.Vtbl.Invoke__STUB(System.IntPtr pComThis) Line 45147
[External Code]
Within my QR Code UserControl, it's using a System.Threading.Timer and it raises an event when a QR Code is found:
timerPreview = new Timer(async (state) =>
{
....
// Check if a result was found
if (result != null && !string.IsNullOrEmpty(result.Text))
{
Debug.WriteLine("Barcode Found: " + result.Text);
if (!this.ContinuousScanning)
{
delay = Timeout.Infinite;
await StopScanningAsync();
}
else
{
delay = this.ScanningOptions.DelayBetweenContinuousScans;
}
OnBarcodeFound(result.Text);
}
timerPreview.Change(delay, Timeout.Infinite);
}, null,
this.ScanningOptions.InitialDelayBeforeAnalyzingFrames,
Timeout.Infinite);
In the page that host the QRCode UserControl, I've got the following code:
private async void ScannerControl_BarcodeFound(string barcodeValue)
{
var dispatcher = CoreApplication.MainView.CoreWindow.Dispatcher;
await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () => {
Debug.WriteLine(barcodeValue);
GetViewModel.BarcodeFound(barcodeValue);
});
}
As you can see, I'm passing the QrCode value to my ViewModel and from there, I sent a message and then re-direct to another page:
public void BarcodeFound(string barcodeData)
{
Messenger.Default.Send<string>(barcodeData, MessengerTokens.QrCodeFound);
this.NavigationFacade.NavigateToMyOtherPage();
}
I could keep going and provide additional code, but as I add additional breakpoints I can see that the code and passing the correct value and going to the correct location but eventually it throws this error. If I add additional error handlers or dispatcher code, it eventually works and goes to the next page as expected but when I click on a button in my CommandBar, it then takes a while and it eventually throws the same error, so by adding these additional bits of code, I feel I'm just pushing down the problem further down the line.
Anyone got any suggestions on how I get around this problem. I wish I could share the full app but definitely can't. So I know it will be hard to provide a solution, but if anyone has suggestions I'd appreciate them.
As I said, I think the issue is a result of a combination of threading and mvvmlight but it's driving me nuts that my test app so far is working exactly as expected, so I'm pretty sure it's not Zxing or my UserControl.
Any help, suggestions would be greatly appreciated or if you need me to provide additional info, please let me know what and I'll try to provide it.
Thanks.
Well, this was a painstaking exercise and a huge waste of my time!
It was down to a few things!!
I was using a different DataService in Releasemode which wasn't implemented. By implemented, I mean all my functions were returning the NotImplementedException or null values.
When passing my model to my ViewModel, I did not check if it was null, thus causing unhandled exceptions.
I had a chain of mvvmlight events (Messenger.Default.Send<>) being triggered and none were checking for error or null values.
While all of these were caused by poor validation from my part, these errors are extremely poorly reported in Release mode! if from the get go, I had received a NullReferenceException or any kind of exceptions, it would have put me in the right direction immediately, but throwing errors such as the one I've had were totally useless but it didn't but lesson learned!!
All I can say is that if this problem ever happens to you, don't waste your time rewriting code or trying to find workarounds. First work your way through your workflow/chain of events and hopefully, you'll eventually catch the culprit.
Hope this helps.
Sadly we were facing a similar issue, ours was involved with setting the qualifier values for changing localization on the fly in the app but came up with mystery fail fast/SharedLibrary native errors. Upgrading the Microsoft.NETCore.UniversalWindowPlatform package from 6.0.4 to 6.0.7 seems to have resolved the issue.
Only thought of this because another place I was researching this error involved someone solving a SharedLibrary problem by upgrading their NETCore package, that case was an earlier one (5.x), but figured it was worth a shot.

Swift UIWebView Optional is nil

In the below example, infoScroller is a UIWebView and println(HTMLDescription) prints a lovely string of HTML. However, the attempt to loadHTMLString gets the runtime error: fatal error: Can't unwrap Optional.None
if let HTMLDescription = self.myData?.content? {
println(HTMLDescription)
infoScroller.loadHTMLString(HTMLDescription, baseURL: nil)
}
I've tried every combination of ! and ? in both the assignment and use of the string but I get this same error every time, though the variable never fails to print out perfectly to the console.
There is another value that I set using the same method and it works fine. Both are strings, but the other one is more simple in that HTMLDescription is multiline and the working one is not.
Edit: The discussion in the comments prompted me to check the infoScroller and it's description as printed in the console is: (#sil_weak UIWebView!) infoScroller =
I'm thinking that's the issue, but I'm not sure what it means or how to fix it.
Edit 2: This has to be the issue. println(infoScroller.description) yields the exact same error.
Got it! This question put me on the path. I was trying to load the content before the view was fully loaded. Moved loadHTMLString() into viewDidLoad(). Stupid simple.

ResolvePrincipal vs SearchPrincipal

So I'm attempting to write something to mimic sharepoint's people picker. I was originally using Utility.ResolvePrincipal with some success, but it was only returning me a single user (obviously). So, I tried to use Utility.SearchPrincipal. Only that's not returning me anything. Here's what I have:
var user = Utility.ResolvePrincipal(_clientContext, _clientContext.Web, nameStart, PrincipalType.user, PrincipalSource.All, null, false);
var users = Utility.SearchPrincipals(_clientContext, _clientContext.Web, nameStart, PrincipalType.user, PrincipalSource.All, null, 10);
_clientContext.ExecuteQuery();
At this point, user.Value has a single user, and users is an empty list. What am I doing wrong?
I eventually solved the issue by changing the PrincipalSource.All call in Utility.SearchPrincipals to just PrincipalSource.UserInfoList. Apparently it was running into some security issue in one of the sets of users, and instead of throwing an error it was just returning an empty list.

Request.Filter in an IIS Managed Module

My goal is to create an IIS Managed Module that looks at the Request and filters out content from the POST (XSS attacks, SQL injection, etc).
I'm hung up right now, however, on the process of actually filtering the Request. Here's what I've got so far:
In the Module's Init, I set HttpApplication.BeginRequest to a local event handler. In that event handler, I have the following lines set up:
if (application.Context.Request.HttpMethod == "POST")
{
application.Context.Request.Filter = new HttpRequestFilter(application.Context.Request.Filter);
}
I also set up an HttpResponseFilter on the application.Context.Response.Filter
HttpRequestFilter and HttpResponseFilter are implementations of Stream.
In the response filter, I have the following set up (an override of Stream.Write):
public override void Write(byte[] buffer, int offset, int count)
{
var Content = UTF8Encoding.UTF8.GetString(buffer);
Content = ResponseFilter.Filter(Content);
_responseStream.Write(UTF8Encoding.UTF8.GetBytes(Content), offset, UTF8Encoding.UTF8.GetByteCount(Content));
}
ResponseFilter.Filter is a simple String.Replace, and it does, in fact, replace text correctly.
In the request filter, however, there are 2 issues.
The code I have currently in the RequestFilter (an override of Stream.Read):
public override int Read(byte[] buffer, int offset, int count)
{
var Content = UTF8Encoding.UTF8.GetString(buffer);
Content = RequestFilter.Filter(Content);
if (buffer[0]!= 0)
{
return _requestStream.Read(UTF8Encoding.UTF8.GetBytes(Content), offset, UTF8Encoding.UTF8.GetByteCount(Content));
}
return _requestStream.Read(buffer, offset, count);
}
There are 2 issues with this. First, the filter is called twice, not once, and one of the requests is just basically a stream of /0's. (the if check on buffer[0] filters this currently, but I think that I'm setting something up wrong)
Second, even though I am correctly grabbing content with the .GetString in the read, and then altering it in RequestFilter.Filter(a glorified string.replace()), when I return the byte encoded Content inside the if statement, the input is unmodified.
Here's what I'm trying to figure out:
1) Is there something I can check prior to the filter to ensure that what I'm checking is only the POST and not the other time it is being called? Am I not setting the Application.Context.Request.Filter up correctly?
2) I'm really confused as to why rewriting things to the _requestStream (the HttpApplication.Context.Request.Filter that I sent to the class) isn't showing up. Any input as to something I'm doing wrong would be really appreciated.
Also, is there any difference between HttpApplication.Request and HttpApplication.Context.Request?
edit: for more information, I'm testing this on a simple .aspx page that has a text box, a button and a label, and on button click assigns the text box text to the label's text. Ideally, if I put content in the textbox that should be filtered, it is my understanding that by intercepting and rewriting the post, I can cause the stuff to hit the server as modified. I've run test though with breakpoints in the module and in code, and the module completes before the code behind on the .aspx page is hit. The .aspx page gets the values as passed from the form, and ignores any filtering I attempted to do.
There's a few issues going on here, but for future reference, what explains the page receiving the unfiltered post, as well as the filter being evaluated twice is that you are likely accessing the request object in some way PRIOR to you setting the Request.Filter. This may cause it to evaluate the inputstream, running the currently set filter chain as is, and returning that stream.
For example, simply accessing Request.Form["something"] would cause it to evaluate the inputstream, running the entire filter chain, at that point in time. Any modification to the Request.Filters after this point in time would have no effect, and would appear that this filter is being ignored.
What you wanted to do is possible, but also ASP.NET provides Request Validation to address some of these issues (XSS). However, Sql Injection is usually averted by never constructing queries through string concatenation, not via input sanitizing, though defense-in-depth is usually a good idea.

drupal_add_js() only adds the JS when no error message (D6)

In my custom form (in a custom module) drupal_add_js() only adds the JS when there is no error message.
My code goes like this:
function ntcf_redo_order_form( &$form_state = array() ) {
global $base_path, $user;
$my_dir = drupal_get_path('module', 'ntcf_redo');
drupal_add_js("$my_dir/order.js", 'module', 'header', FALSE, TRUE, FALSE);
$form = array();
...
return $form;
}
If the validation function used _form_set_error()_ to display an error message and highlight the offending field, the message is displayed and the field highlighted, but the _drupal_add_js()_ call does nothing. Without a pending error message to display, all is well.
EDIT: this problem does not occur with drupal_set_message(), only with form_set_error().
I tried adding the 3 later parameters to the *drupal_add_js()* call to tell it to not optimize it (don't combine it with other JS files). There is no mention of the file order.js in the HTML, and it makes no difference whether I use the last 4 parameters ('header', FALSE, TRUE, FALSE) or not.
In Admin/Performance, I turned off Optimize Javascript Files, and pretty much all caching, which also made no difference.
Extra Details:
I'm not sure if this makes a difference, but it wouldn't surprise me, so here goes:
What I'm doing here is a multi-part "wizard" form that allows the user to proceed forward and go back. Also, many of the pages use AJAX, so I need to do all the "required" field validation in the _submit function instead of letting Drupal do it automatically (since that makes a mess of AJAX). So, if there's a "required" field that's missing, the _submit() function sets an error message, and the form generation function generates the same form again (with the additional decoration resulting from the error message).
Also: this is off-topic, but it might help someone using Google: when doing a multi-page form that allows going backward, you MUST assign a weight to every item on the form, or else the fields tend to "wander" when you go backwards.
Any ideas?
I had the same problem, this is a workaround I found (for Drupal 7, may work in 6) :
1. in your form setup (or hook_form_alter), do this :
$form['#post_render'][]='yourfunction';
2. define :
function yourfunction($content,$element){
$my_dir = drupal_get_path('module', 'ntcf_redo');
drupal_add_js("$my_dir/order.js", 'module', 'header', FALSE, TRUE, FALSE);
return $content;
}
I think this works (while your approach does not), because hook_form_alter (and/or hook_form)
do NOT get called again for a prepared/cached form, so the initial form load WILL load the javascript, but subsequent posts will NOT.
HTH
Mikes answer ($form['#post_render'][]='yourfunction';), will work, though its not the optimal way and will cause issues with drupal_add_js.
The best way to do this is by adding your javascript via the form api '#attached'.
Instead of using drupal_add_js or a new callback on the '#post_render':
$form['#attached']['js'] = array(
drupal_get_path('module', 'module_name') .'/file/path/filename.js',
);
You may pass in a 'css' array as well. Being an array, you can pass in as may files as you want.
*This is for Drupal 7. Other versions may be different.

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