B4J Question B4j IDE crashes after clicking on List variables when using JAVA version OpenJDK 19

[johnerikson]

Declared variables of type List cannot be read by pointing to it. B4j stops immediately
without notifications.
I'm using Windows 11 and B4j 10.30

Note that there is no problem with compiling and running the program if you avoid clicking on variables of type List.
OpenJDK 14, on the other hand, works satisfactorily in this regard

 

[Erel]

Does the IDE itself crash? Or the debug app?

 

[Swissmade]

Sounds something like this I have seen

B4J Bridge and List's

Revere back to https://www.b4x.com/android/forum/threads/application-running-in-debug-mode-stop.165241/#post-1013040 I think I found something. When I debug using the B4J-Bridge to Linux Raspberry pi and go over a list in debug mode then I get this error. WARNING: An illegal reflective access...

www.b4x.com

 

[johnerikson]

No not IDE tself, the stop does not generate an error message, but just jumps out of debugging mode!

 

[Erel]

I'm unable to reproduce it with a simple list:

If you are able to reproduce it in a small project then please upload it.

 

[johnerikson]

After testing small projects, it turns out that the problem occurs only in non IO projects (server-proj).

Sending a small non io project, where I added a list variable and a breakpoint on StartMessageLoop.
After start - running, when pointing to the variable lMsgOK, the debugger appears!

 

[Sagenut]

Try this version.
You were still using the HTTP modules that are deprecated by long time.
I removed the modules and added the library
jOKHttpUtils2
that is included with B4J.
Let us know if now it works.

 

[johnerikson]

Lib jOKHttpUtils2 is not visible in the B4j lib list. Where can I find that library?

 

[Sagenut]

It should be visible.
It's an internal library.
In the projects it's already flagged so you should see it in the upper part.

 

[johnerikson]

A miserable miss, after checking it turns out that jOKHttpUtils2 is there in the list!
Unfortunately, after testing your version, the Debugger kept crashing when pointing to the List variable!

 

[Sagenut]

I can't test it deeply because it looks that it needs some kind of token for DuckDns

 

[johnerikson]

You can run your own version by annotating Duckdn's subs and adding a breakpoint to line 29

'Non-UI application (console application)
#Region  Project Attributes
    #CommandLineArgs:
    #MergeLibraries: False
#End Region

Sub Process_Globals
    'Private domain As String = "xxx"
    'Private token As String = "yyy"
    Private updateIp As Timer
    Private srvr As Server
    Public filesFolder As String = "uploaded"
    Dim lMsgOk As List
End Sub

Sub AppStart (Args() As String)
    updateIp.Initialize("updateIp", 10 * 60 * 1000) '10 minutes
    updateIp.Enabled = True
    'UpdateIp_Tick
    srvr.Initialize("srvr")
    srvr.Port = 54021
    File.MakeDir(File.DirApp, filesFolder)
    srvr.AddHandler("/upload", "Upload", False)
    srvr.AddHandler("/test", "Test", False)
    srvr.Start
    Log("Server started")
    lMsgOk.Initialize
    lMsgOk.Add("Test")
    StartMessageLoop
End Sub

'Sub UpdateIp_Tick
'    Dim j As HttpJob
'    j.Initialize("j", Me)
'    j.Download2("http://www.duckdns.org/update", Array As String("domains", domain, "token", token, _
'        "ip", ""))
'End Sub
'
'Sub JobDone (j As HttpJob)
'    If j.Success = True Then
'        Log("Update DuckDNS: " & j.GetString)
'    Else
'        Log("Error updating Duck DNS: " & j.ErrorMessage)
'    End If
'    j.Release
'End Sub

 

[Sagenut]

Oh Yes, now I got it.
Yes I can confirm the BUG or the strange behaviour of Java 19.
After the program stopped at breakpoint, with Java 14 you can hover variables to see values with no problems.
With Java 19 when hovering a variable you can see the value just for a couple of seconds and then the debug windows will close.

 

[teddybear]

I'm unable to reproduce it with a simple list:

View attachment 165637
If you are able to reproduce it in a small project then please upload it.

The issue is only happened in Non-UI project. @Erel
This is caused Illegal reflective access by JDebug.jar to field java.util.ArrayList.elementData.
The illegal access operations has been denied in jdk17+
It can be solved by adding JVM args.

#VirtualMachineArgs:--add-opens java.base/java.util=ALL-UNNAMED

 

[Erel]

Good catch @teddybear !

It will be fixed for the next update.

 

[johnerikson]

Good!
Super and impressive that it got a solution. It also works with JWC args.
Thanks!