Develop Reference

Working with MCRTsim simulator on a LINUX system

I am trying to use the MCRTsim simulator in my research work. As documented in https://resl.csie.nptu.edu.tw/dokuwiki/doku.php?id=guide, I run this command java -jar MCRTsim/dist/MCRTsim2.8.jar in specified directory, but the simulation window did not pop up. Instead, I got following exceptions:
Exception in thread "main" java.lang.NullPointerException
at java.base/java.io.Reader.<init>(Reader.java:167)
at java.base/java.io.InputStreamReader.<init>(InputStreamReader.java:109)
at org.apache.commons.io.IOUtils.copy(IOUtils.java:2440)
at org.apache.commons.io.IOUtils.toString(IOUtils.java:1084)
at org.apache.commons.io.IOUtils.toString(IOUtils.java:1110)
at userInterface.frontEnd.SimulationViewer.setComboBox(SimulationViewer.java:529)
at userInterface.frontEnd.SimulationViewer.initialize(SimulationViewer.java:359)
at userInterface.frontEnd.SimulationViewer.<init>(SimulationViewer.java:97)
at userInterface.UserInterface.initialize(UserInterface.java:45)
at userInterface.UserInterface.<init>(UserInterface.java:31)
at mcrtsim.MCRTsim.main(MCRTsim.java:55)
I am using Ubuntu system and JDK 11. I have not used Java much. I am not able to understand what this error is saying. Would anyone please help me with this?

Finally, I got the solution to this problem. I think this simulator is compatible with openjdk-8. So, I removed openjdk-11 from my system and installed openjdk-8.
After installing openjdk-8, I run the command java -jar dist/MCRTsim2.8.jar . This time I got the following error:
Exception in thread "main" java.awt.AWTError: Assistive Technology not
found: org.GNOME.Accessibility.AtkWrapper
at java.awt.Toolkit.loadAssistiveTechnologies(Toolkit.java:807)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:886)
at java.awt.Window.getToolkit(Window.java:1358)
at java.awt.Window.init(Window.java:506)
at java.awt.Window.<init>(Window.java:537)
at java.awt.Frame.<init>(Frame.java:420)
at javax.swing.JFrame.<init>(JFrame.java:233)
at userInterface.UserInterface.initialize(UserInterface.java:37)
at userInterface.UserInterface.<init>(UserInterface.java:31)
at mcrtsim.MCRTsim.main(MCRTsim.java:55)
After that, I followed this blog https://askubuntu.com/questions/695560/assistive-technology-not-found-awterror to rectify the above error.
I just commented this line #assistive_technologies=org.GNOME.Accessibility.AtkWrapper in /etc/java-8-openjdk/accessibility.properties file.
And, it started working.

UnsatisfiedLinkError for tomcat7 windowsOS

I am getting below error on my web app.
java.lang.UnsatisfiedLinkError: Can't obtain updateLastError method for class com.sun.jna.Native
com.sun.jna.Native.initIDs(Native Method)
com.sun.jna.Native.<clinit>(Native.java:139)
com.sun.jna.Pointer.<clinit>(Pointer.java:41)
com.sun.jna.platform.win32.WinNT$HANDLEByReference.<init>(WinNT.java:1114)
com.sun.jna.platform.win32.WinNT$HANDLEByReference.<init>(WinNT.java:1110)
waffle.windows.auth.impl.WindowsAuthProviderImpl.logonDomainUserEx(WindowsAuthProviderImpl.java:193)
waffle.windows.auth.impl.WindowsAuthProviderImpl.logonDomainUser(WindowsAuthProviderImpl.java:181)
waffle.windows.auth.impl.WindowsAuthProviderImpl.logonUser(WindowsAuthProviderImpl.java:212)
waffle.apache.MixedAuthenticator.post(MixedAuthenticator.java:233)
waffle.apache.MixedAuthenticator.authenticate(MixedAuthenticator.java:112)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:577)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
I searched that it may be due to some old version access of jna but removing jna is giving me NoClassDefErrors for com.sun.jna.Pointer. Also tried -Djna.nosys=true but its also not solving the issue.
I also tried -Djava.library.path=
from What is the cause of an UnsatisfiedLinkError? but it is also not working..
Any suggestion is highly appreciated.

I resolved this by deleting an old jnidispatch.dll file from my machine.
I'm using Gradle and Tomcat on Windows 7.
Delete the jnidispatch.dll file in C:\Users\<username>\.gradle\native\jna\win32-amd64

Don't have enough rep to just comment, but this is vaguely similar to a question i asked a couple years ago called UnsatisfiedLinkError, despite setting Djava.library.path variable
Somebody suggested making sure i was using the right architecture type, i.e. using 64 bit jdk with 64 bit Tomcat & 32 with 32. Does that match up?

Java - JMF unable to add a Capture or Video device

I am trying to capture video via JMStudio.
When I try to run jmfinit it not detect my webcam and also the device is not listed in jmfregistry.
When I try to add a device manually it is giving me an error Could not add item
I have tried to run both (jmfinit and jmfregistry) as administrator and even tried to change the security settings but nothing seems to work.
I am using Windows 7
I re-installed OS also..
Please find snap shots of error message.
error popup message as shown in snapshot 1
I'm getting below error when i try to run my application
Exception in thread "VFW Request Thread" java.lang.UnsatisfiedLinkError: JMFSecurityManager: java.lang.UnsatisfiedLinkError: no jmvfw in java.library.path
at com.sun.media.JMFSecurityManager.loadLibrary(JMFSecurityManager.java:206)
at com.sun.media.protocol.vfw.VFWCapture.<clinit>(VFWCapture.java:19)
at com.sun.media.protocol.vfw.VFWSourceStream.doConnect(VFWSourceStream.java:241)
at com.sun.media.protocol.vfw.VFWSourceStream.run(VFWSourceStream.java:763)
at java.lang.Thread.run(Thread.java:745)

solution for above Problem..
JMF Studio is 32 bit supporting software so we must install 32bit supported JDK and also Eclipse then we not get any exceptions and errors.
Once Run your application then Automatically Your system webcam will "On".

JMF Studio is 32 bit it not support to 64bit OS/Eclipse,
and another reason is may be Environment variable not defined.

Play framework runtime error on OS X

I'm trying to install Play 2.2 on a fresh MacBook Pro with Java 7. Scala has already been installed. Here's what I get:
Okihara-MacBook-Pro:Extensions okihara$ play help
Exception in thread "main" java.lang.IncompatibleClassChangeError: Expected static method scala.Array$.unapplySeq(Ljava/lang/Object;)Lscala/Option;
at xsbt.boot.Boot$.main(Boot.scala:14)
at xsbt.boot.Boot.main(Boot.scala)
I saw Issue getting SBT to work on Mac OS X but there's no conclusive answer. I tried running the Scala REPL and that seems to work well too.
I only used Play on Linux before, this is my first attempt to install it on OS X.
Where should I look?
EDIT
As done in the other SO question, I get the above message with the scala-* jars in the Library/Java/Extensions folder. If I remove them, I get:
Okihara-MacBook-Pro:Extensions okihara$ play
Exception in thread "main" java.lang.NoSuchMethodError: org.apache.ivy.core.RelativeUrlResolver.$init$$6ce060cb(Lscala/collection/mutable/HashTable$HashUtils;)V
at scala.collection.mutable.HashMap.<init>(HashMap.scala:39)
at scala.collection.mutable.HashMap.<init>(HashMap.scala:55)
at scala.collection.mutable.Map$.empty$7fee4dfc(Map.scala:68)
at scala.collection.generic.MutableMapFactory.newBuilder(MutableMapFactory.scala:29)
at scala.collection.generic.GenMapFactory.apply$41cb962a(GenMapFactory.scala:47)
at scala.sys.SystemProperties$.propertyHelp$lzycompute(SystemProperties.scala:62)
at scala.sys.SystemProperties$.noTraceSupression$lzycompute(SystemProperties.scala:80)
at scala.sys.SystemProperties$.noTraceSupression(SystemProperties.scala:80)
at scala.util.control.NoStackTrace$.<init>(NoStackTrace.scala:31)
at scala.util.control.NoStackTrace$.<clinit>(NoStackTrace.scala)
at scala.util.control.BreakControl.fillInStackTrace(Breaks.scala:93)
at java.lang.Throwable.<init>(Throwable.java:250)
at scala.util.control.BreakControl.<init>(Breaks.scala:93)
at scala.util.control.Breaks.<init>(Breaks.scala:28)
at scala.collection.Traversable$.<init>(Traversable.scala:96)
at scala.collection.Traversable$.<clinit>(Traversable.scala)
at scala.package$.<init>(package.scala:46)
at scala.package$.<clinit>(package.scala)
at scala.Predef$.<init>(Predef.scala:90)
at scala.Predef$.<clinit>(Predef.scala)
at scala.Array$.unapplySeq(Array.scala:443)
at xsbt.boot.Boot$.main(Boot.scala:14)
at xsbt.boot.Boot.main(Boot.scala)

Removing ivy-*.jar from /Library/Java/Extensions solved the
issue.
FWIW, I also have no scala*.jar in the extensions folder and I'm running Java 1.7.0_21. Play is symlinked as advised. HTH.

Jacob (Java / COM / ActiveX) Throws ComFailException

I am using Jacob a Java-COM bridge and I have placed the required dll to -C:\WINDOWS\system32\jacob-1.14.3-x86.dll. I have also added the required jar file to -
C:\Program Files\Java\jdk1.6.0_18\jre\lib\ext\jacob-1.14.3.jar.
Until yesterday I was able to use it, today I uninstalled some unrequired .Net softwares on my machine and suddenly it stopped working and throws following error -
com.jacob.com.ComFailException: Can't co-create object
at com.jacob.com.Dispatch.createInstanceNative(Native Method)
at com.jacob.com.Dispatch.<init>(Dispatch.java:101)
at com.jacob.activeX.ActiveXComponent.<init>(ActiveXComponent.java:58)
My machine belongs to "x86 Family 15 Model 4 Stepping 3". I have tried to de-register/register the dll using regsvr32.exe but to no luck. I have no idea how to bring it to work again..other wise I will have to format my machine..geeks pls hlp me out !

I wonder if anyone faced similar problem by any chance..
Anyways I had no other option than to restore my machine to last working date.
I guess some JAVA-COM class entries would have been accidently deleted from the registry.
Had no idea which was it exactly..
Finally "System Restore" was my solution :)