I'm trying to use CoAP.Net using the most basic example could ever be
var server = new CoapServer();
server.Start();
Console.ReadKey();
However, even for this simple test the application terminates due to a StackOverflow exception
I took a look at the start method on their GitHub repository and couldn't find a single line of code that might cause a StackOverflow exception
I'm using version 1.1.0 on a .NET Core 2.1 project running on a MacOS machine and that makes me wonder if the library is still working
Related
I am attempting to upgrade from Wicket 9.0.0 to Wicket 9.3.0. When I change the version in a quick-start application, everything is fine.
The problem occurs in my real application, where we were originally using Jakarta Enterprise Beans 8.0.0. At runtime, when a database access was attempted, we got an exception with the following message:
Last cause: net.sf.cglib.proxy.MethodInterceptor not found by org.objectweb.asm [23]
Trying to use Jakarta EE 9.1 instead
I changed my pom.xml as follows:
<jakartaee>9.1.0</jakartaee>
<wicket.version>9.3.0</wicket.version>
I downloaded the jar for Jakarta EE 9.1, changed "javax" to "jakarta" throughout my application, rebuilt it and tried to run again.
The result was still not perfect, but significantly better than before: a plain old null pointer exception instead of any weird errors about cglib.
Here's the section of code that now causes the trouble:
#EJB(name = "AdminNotesFacade")
private AdminNotesFacade adminNotesFacade;
public AdminNotesFacade getAdminNotesFacade() {
return adminNotesFacade; //ACTUALLY RETURNS NULL
}
So now the big question is: what do I need to do/change to make the #EJB work instead of returning null?
Checking the Payara log, I get this error:
java.lang.RuntimeException: Unable to load the EJB module. DeploymentContext does not contain any EJB. Check the archive to ensure correct packaging for D:\Dev\icase2\target\icase2.
If you use EJB component annotations to define the EJB, and an ejb or web deployment descriptor is also used, please make sure that the deployment descriptor references a Java EE 5 or higher version schema, and that the metadata-complete attribute is not set to true, so the component annotations can be processed as expected
at org.glassfish.ejb.startup.EjbDeployer.prepare(EjbDeployer.java:189)
Adding further details, 2022-05-06
I wonder if we were going off on the wrong track when we thought that we could fix this by upgrading our jakartaee version. From Wicket 9.0 to 9.3 is only a change of minor version and you wouldn't expect to have to make such fundamental changes to get a minor upgrade working.
I've tried using Wicket 9.9.1 instead, in case this problem has been fixed in more recent versions, but it's exactly the same.
Anyway, I have created a very small "quick-start" application, based on Wicket's own templates, to reproduce the problem. I have stuck with the original "javax" version, and added just one EJB - a JavaMail bean. I think it's probably interesting to know that it's not a specifically database-related issue. We just can't seem to load any EJBs at all.
In the Wicket 9.0.0 version, a simple form is displayed on the home page, allowing the user to enter their email address. When they submit the form, a test message is sent to that address. It works fine.
Then if I change the Wicket version to 9.3.0 but make no other changes at all, it doesn't even get to the stage of displaying the home page, it immediately crashes with the message "Last cause: net.sf.cglib.proxy.MethodInterceptor not found by org.objectweb.asm [23]"
For what it's worth, here's the code that triggers the error.
public class HomePage extends WebPage {
#EJB(name = "EmailerFacade")
private EmailerFacade emailerFacade;
private static final long serialVersionUID = 1L;
private String sendTo = "";
public HomePage(final PageParameters parameters) {
super(parameters);
add(new Label("version", getApplication()
.getFrameworkSettings().getVersion()));
FeedbackPanel feedback = new FeedbackPanel("feedback");
add(feedback);
final Form emailForm = new Form("emailForm") {
#Override
protected void onSubmit() {
emailerFacade.sendMessage(sendTo, "Test message from quick-start",
"Version is " + getApplication().getFrameworkSettings()
.getVersion());
info("Tried to send message to " + sendTo);
}
};
add(emailForm);
final TextField<String> emailAddress = new TextField<>("emailAddress",
new PropertyModel<>(this, "sendTo"));
emailAddress.setLabel(Model.of("Email address"));
emailAddress.setRequired(true);
emailForm.add(emailAddress);
}
}
Wicket 9.x is based on javax.servlet APIs. To deploy it on jakarta.servlet supporting web container you will need to migrate the bytecode with a tool like https://github.com/apache/tomcat-jakartaee-migration.
I am not sure whether Payara does something smart at runtime to support both javax.** and jakarta.** classes.
Tomcat 10.x supports migration of the classes at application start time by deploying your app in the special $CATALINA_HOME/webapps-javaee folder.
This answer was actually provided by Sven Meier. He commented:
Use the new system property to switch to ByteBuddy in Wicket 9.x:
-Dwicket.ioc.useByteBuddy=true
To expand a bit on this, I found I needed to do three things:
Set the system property "wicket.ioc.useByteBuddy" to true as specified by Sven
Add a dependency on byte buddy
Upgrade to a higher version than I was initially attempting to do: 9.3.0 was not good enough. I see in a comment above by Sven, he says that the migration to byte buddy was actually done in 9.5. So in fact I upgraded to the latest version, which is currently 9.9.1.
Here is the dependency on byte buddy that I added:
<dependency>
<groupId>net.bytebuddy</groupId>
<artifactId>byte-buddy</artifactId>
<version>1.12.10</version>
</dependency>
We have a Xamarin.Forms project that needed to use the sqlite local db to store date. EF Core's sqlite library was used to set this up and by different developers from different PCs (vs 2019). Initially, it was used with the Database.EnsureCreated() function and later with ef core's migrations. All went smooth for more than a month.
Last week all of a sudden the android app wouldn't start on any one's PC due to some error with sqlite. It showed the following error:
Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
I spent a while trying all kinds of fixes and rollbacks thinking it was an issue with the code. This included the following:
Deleted obj and bin folders, cleaned and rebuilt for all below steps.
Downgraded the version of ef to 2.2.3 (the version we started with)
Rolled back to git commits up to a week back
Upgraded the versions of dependencies of ef core
Removed the past few migrations
Downgraded xamarin forms to 3.6.x
After trying the above and several other fixes, finally upgrading the versions of java and android SDK worked last Friday (on all PCs). Once this fix worked everything went smooth that day. On Tuesday once again the issue was back (no library updates or code changes). A deeper look at EF Cores logging shows that it crashes the moment it attempts to connect to a db.
The issue can be replicated on the android devices but not the emulators. I am not sure if there is some new permission in android we need to request for.
I finally created a new xamarin forms project with sqlite setup. I used the pcl library and ef core. I still found the same error.
Here is the git hub that replicates the issue https://github.com/neville-nazerane/xamarin-site
Update
Just something i noticed. eariler my database file was named "main.db". Now no matter what i change this file name to or no matter what variables i change. it always shows database name as "main" in logs. Not sure if changing the db name would fix the issue. However, never found a way to change this db name. I tried different connection strings, it just said "database" and "db" were unknown keys
Update
Steps to replicate:
using (var db = new AppDbContext())
{
db.Add(new Person {
Age = 55,
Name = "Neville"
});
db.SaveChanges();
Person[] alldata = db.People.ToArray();
}
The definitions of Person and AppDbContext are quite obvious. So, with the spirit of not making the question too long, I am not posting it here. However, if required I can post them too.
This is a bug with the Xamarin.Forms and Mono.
It was detected since a couple of months ago, it was fixed but then there was some regression (with VS 2019 v16.1).
Even with the latest release (v16.1.2) the bug still happens, so we need to wait for a fix.
Sources:
https://github.com/mono/mono/issues/14170
https://github.com/xamarin/xamarin-android/issues/3112
https://github.com/xamarin/xamarin-android/issues/2920
Due to slight differences of the particular file systems on the native side, I would suggest creating an interface to handle the actual database file handling on the native application level.
So here is how I implemented SQLite using the nuget package SQLite.Net-PCL:
In the shared project, create a new interface, for instance FileHandler.cs
public interface IFileHandler
{
SQLite.SQLiteConnection GetDbConnection();
}
You may want to extend that with more methods to save or retrieve various files, but for now we will just have the GetDbConnection Method to retrieve a working SQLite Connection.
Now in your Android implementation, we add the native implementation to that interface:
Create a new class called FileHandler.cs in your android project:
[assembly: Dependency(typeof(FileHandler))]
namespace YourProjectName.Droid
{
public class FileHandler : IFileHandler
{
public SQLite.SQLiteConnection GetDbConnection()
{
string sqliteFilename = "YourDbName.db3";
string path = Path.Combine(GetPersonalPath(), sqliteFilename);
SQLiteConnectionString connStr = new SQLiteConnectionString(path, true);
SQLiteConnectionWithLock connection = new SQLiteConnectionWithLock(connStr, SQLiteOpenFlags.Create | SQLiteOpenFlags.ReadWrite | SQLiteOpenFlags.NoMutex);
return connection;
}
private string GetPersonalPath()
{
return Environment.GetFolderPath(Environment.SpecialFolder.Personal);
}
}
}
Now back again in your shared code you can access that connection with the following code:
using (SQLiteConnection connection = DependencyService.Get<IFileHandler>().GetDbConnection())
{
// Do whatever you want to do with the database connection
}
Alright mate, I don't understand what issue you are facing. It might be an issue with your machine, I'd suggest using another computer/laptop.
I took the exact code that you shared on the Github. I was able to build it on my Mac computer in VS 2019 and installed the application in debug mode on my phone. I was able to add a date successfully, as you can see in the picture, and I placed an Exception Catchpoint and faced no exceptions.
I then proceeded to add another entry with the same details and it errored out with the message that you can see here
I would also suggest using Xamarin Profiler or any other Android logger to see the Stack Trace that you aren't able to see in your application output. It will give you details of the error, that you can share here for us to understand better.
This is a more specific continuation of my previous Post: Custom Vision on HoloLens
I'm still using the Unity Project from this blogpost: https://mtaulty.com/2018/03/29/third-experiment-with-image-classification-on-windows-ml-from-uwp-on-hololens-in-unity/
I had issues that my own exported models don't work with the the code at some point. Now it is possible to export onnx models of version 1.2, but the the old code seems to not be compatible with the new version.
in the line var evalOutput = await this.learningModel.EvaluateAsync(this.inputData); in the MainScript it throws The binding is incomplete or does not match the input/output description. (Exception from HRESULT: 0x88900002)
Does someone know what I need to change so it works with the new version on HoloLens? Thanks in advance!
You can find a similar question here: Windows ML's OS requirement
In summary, you are right about needing to update the PC and the Hololens, but the build number you need is 17763 to be on the production version of RS5.
You could also be hitting this issue: Cannot load model using WinML
where the binding isn't quite setup properly.
If you're still having issues, please post the SDK and OS version you're on, as well as the ONNX model version.
When I am trying to create a new instance of AlternatorDBClientV2 I am getting below exception.
java.lang.NoSuchMethodError: com.amazonaws.transform.JsonErrorUnmarshaller: method ()V not found
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.init(AlternatorDBClientV2.java:106)
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.(AlternatorDBClientV2.java:100)
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.(AlternatorDBClientV2.java:95)
I am using 0.12.0 version of alternator.
any idea why this exception is occurring.
Thanks!!
I recently ran into this as well.
JsonErrorUnmarshaller is a class internal to Amazon's SDK, and if you take a look in the jar's source, they apparently changed the constructor to take some arguments recently.
That means that the line at https://github.com/mboudreau/Alternator/blob/master/src/main/java/com/michelboudreau/alternatorv2/AlternatorDBClientV2.java#L106 would fail, as it calls new JsonErrorUnmarshaller().
I'm afraid you might need to configure local DynamoDB. Alternator hasn't been updated in 2 years, there's going to be incompatibilities.
I have a classic ASP application written many years ago that I'm trying to fix.
The following lines recently stopped working after w7 sp1 was applied.
set address = Server.CreateObject("ADOR.Recordset")
count = lo_connection.GetRecordset(sql,address,false, error)
Set RDF2 = Server.CreateObject("RDSServer.DataFactory")
Set teststring = RDF2.ConvertToString(address)
It fails on the last line there saying "Microsoft VBScript runtime error: Class doesn't support Automation"
A bit of searching found several articles like this one
http://blogs.technet.com/b/asiasupp/archive/2011/03/14/changes-in-mdac-adodb-com-components-in-windows-7-service-pack-1.aspx
that described the problem exactly. Where I am failing is that none of the suggested fixes seems to fix the problem. Any suggestions?
The solutions described in the link are not relevant here, since ASP is not early-bound - it uses OLE Automation. It might be worth re-registering the component which creates RDSServer.DataFactory objects (which is C:\Program Files\Common Files\system\msadc\msadcf.dll on my machines).
I looked up this object, and I found this Microsoft web page:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms681447(v=vs.85).aspx
"This feature will be removed in a future version of Windows. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Applications that use RDS should migrate to WCF Data Service."
Doesn't sound too good.