DDE server Error UnsatisfiedLinkError - java

I followed a tutorial that create DDE server but i get this error :Exception in thread "main" java.lang.UnsatisfiedLinkError: com.neva.ExternalObject.toExternalHeap(Ljava/lang/String;)
the tutorial is here :
JAVADDE

UnsatisfiedLinkError Thrown if the Java Virtual Machine cannot find an appropriate native-language definition of a method declared native.
Usually you need to add "java.library.path" parameter like
java -Djava.library.path="C:\dde" Example
or put DLL to startup folder.
Also, if you will not be able to solve current problem you can try another JDDE library.

Related

maven pass arguments to pom java.library.path cplex

I am trying to resolve this error that I keep getting:
java.lang.UnsatisfiedLinkError: no cplex1262 in java.library.path
java.library.path must point to the directory containing the CPLEX shared library
try invoking java with java -Djava.library.path=...
Exception in thread "main" java.lang.UnsatisfiedLinkError: ilog.cplex.Cplex.CPXopenCPLEX([I)J
at ilog.cplex.Cplex.CPXopenCPLEX(Native Method)
at ilog.cplex.CplexI.init(CplexI.java:5722)
at ilog.cplex.CplexI.(CplexI.java:611)
at ilog.cplex.IloCplex.(IloCplex.java:10384)
I am using maven with java and I am trying to call cplex library. I think something needs to change in the pom file but i dont know what. Please help. Thanks.
One possible cause for could be your dll being in 32 or 64 bits and your java being in the opposite architecture.
Try verifying that your java and cplex.dll match. I got this information from the below post UnsatisfiedLinkError, despite setting Djava.library.path variable

java.lang.UnsatisfiedLinkError: no so in java.library.path

When i'm trying to load the .so file from the Java, i'm getting error like this.
Exception in thread "main" java.lang.UnsatisfiedLinkError: no yeslib.so in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1681)
at java.lang.Runtime.loadLibrary0(Runtime.java:840)
at java.lang.System.loadLibrary(System.java:1047)
at com.rct.micros.util.GetCustClass.getScratchCode(GetCustClass.java:76)
at com.rct.micros.util.GetCustClass.main(GetCustClass.java:39)
I have tried System.load(absoulte path) and System.loadLibrary(sofilename). Both are giving the same error. When i copy this so file into usr/lib/jvm package, it is working..
can anyone help how to get this solved using Java. i'm running on linux box.
It's possible that the library is on your path, but it can't be loaded for some other reason.
A trick I've used to debug problems like this is to run java -Xrunsofilename
-Xrun is the JVM option to load JVMPI libraries (the old profiling interface). If it succeeds, it will load the library and complain that it's not an agent library. But if it fails (hopefully!) it will print an error message. This is usually a more descriptive error message than what you get from the UnsatisfiedLinkError.

Java Attach API: UnsatisfiedLinkError

When using the Java Attach API, I'm getting the following link error on Linux (tried it on different machines) only:
Exception in thread "main" java.lang.UnsatisfiedLinkError: sun.tools.attach.WindowsAttachProvider.tempPath()Ljava/lang/String;
at sun.tools.attach.WindowsAttachProvider.tempPath(Native Method)
at sun.tools.attach.WindowsAttachProvider.isTempPathSecure(WindowsAttachProvider.java:74)
at sun.tools.attach.WindowsAttachProvider.listVirtualMachines(WindowsAttachProvider.java:58)
at com.sun.tools.attach.VirtualMachine.list(VirtualMachine.java:134)
at sun.tools.jconsole.LocalVirtualMachine.getAttachableVMs(LocalVirtualMachine.java:151)
at sun.tools.jconsole.LocalVirtualMachine.getAllVirtualMachines(LocalVirtualMachine.java:110)
...
Interestingly, on Solaris and Windows it's working out of the box.
I tried out several combinations of specifying java.library.path to point to the directory which contains the libattach.so but with no luck.
What's wrong here?
And as a bonus question: Is there a way to see which native library is actually bound to a java class?
Different AttachProvider are used on different platforms. On Linux, it shouldn't use sun.tools.attach.WindowsAttachProvider. It is for Windows.
[solaris] sun.tools.attach.SolarisAttachProvider
[windows] sun.tools.attach.WindowsAttachProvider
[linux] sun.tools.attach.LinuxAttachProvider
This is configured in a resource file META-INF\services\com.sun.tools.attach.spi.AttachProvider (typically this file exists in tools.jar). It will search CLASSPATH to get first occurrence of this resource file and read the AttachProvider implementation class from it.
So you can probably resolve this problem by search sun.tools.attach.WindowsAttachProvider in your CLASSPATH. Possibly you have included a tools.jar from Windows.

UnsatisfiedLinkError and NoClassDefFoundError : Running Java Mapscript on Ubuntu 11.10

We have coded and run a dynamic web application using MAPSERVER(Version 6.0.1) on windows platform using Java Technology. Now, there is need of deploying it on Ubuntu 11.10. We have installed Apache Tomcat 6.0, Mapserver 6.0.1, Apache 2.0, and FWTools-2.0.1(As this package contain all required tools for mapserver if I am not wrong, so I didn't feel any other tools to be installed). We have deployed the war file(and put application without) in Apache Tomcat 's Webapps folder. I even got the index page which dont have code related with mapscript api. But while fetching the other servlet with mapscript we are getting following error...
java.lang.UnsatisfiedLinkError: no mapscript in java.library.path
java.lang.ClassLoader.loadLibrary(ClassLoader.java:1681)
java.lang.Runtime.loadLibrary0(Runtime.java:840)
java.lang.System.loadLibrary(System.java:1047)
edu.umn.gis.mapscript.mapscriptJNI.<clinit>(mapscriptJNI.java:23)
edu.umn.gis.mapscript.mapObj.<init>(mapObj.java:283)
Again while refreshing the browser page where the above error was displayed, I got a change,
java.lang.NoClassDefFoundError: Could not initialize class
edu.umn.gis.mapscript.mapscriptJNI
edu.umn.gis.mapscript.mapObj.<init>(mapObj.java:283)
I searched on net about the above problem. But finally blank. Please, provide idea about the above problem.
I'm not going to explain why you're getting the UnsatisfiedLinkError, but instead I'll explain why you are getting the NoClassDefFoundError when you reload the page.
A NoClassDefFoundError with a message Could not initialize class ... is thrown by the JVM when it attempts to initialize a class that it has already tried and failed to initialize.
The first of your two stacktraces contains the line
edu.umn.gis.mapscript.mapscriptJNI.<clinit>(mapscriptJNI.java:23)
The method name <clinit> denotes the static initializer, of the class mapscriptJNI. So, at the point that the UnsatisfiedLinkError was thrown, the JVM was trying to initialize this class. Looking at the error message, it seems that this static initializer tried to load the native code library mapscript but failed.
This UnsatisfiedLinkError causes the mapscriptJNI class to fail to initialize successfully. The JVM keeps a record of all classes that fail to initialize, and if you attempt to initialize one of those classes again, you'll get a NoClassDefFoundError with a message saying that it could not initialize that class.
When you refresh the page, you end up causing the JVM to attempt to initialize the class mapscriptJNI a second time. Of course, this class failed to initialize the previous time. Your second stacktrace contains exactly the error I've described.
In short, the UnsatisfiedLinkError is the real error here. Fix that and the other one will go away.
I would check the following 2 items:
Is the mapscript.jar file on Tomcat or at least your webapp's classpath? (NoClassDefFoundError is your big clue here)
Is the libmapscript.so on either your LD_LIBRARY_PATH or -Djava.library.path? (UnsatisfiedLinkError since the shared object cannot be found)
Try having a look at this post, near the Running Java Mapscript (on Linux) section.
Hope that helps!

UnsatisfiedLinkError - What can this error mean? Every hint is useful!

In Eclipse I get this eror:
Exception in thread "main"
java.lang.UnsatisfiedLinkError:
com.nokia.mid.impl.isa.util.SharedObjects.nativeSetTable(Ljava/util/Hashtable;)Ljava/util/Hashtable;
I can see SharedObjects, but nativeSetTable doesn't seem to be a method. It might however be hidden -> I don't have access to the source code.
This was my code:
connection = (HttpConnection)Connector.open(this.url);
This is the trace:
Exception in thread "main" java.lang.UnsatisfiedLinkError:
com.nokia.mid.impl.isa.util.SharedObjects.nativeSetTable(Ljava/util/Hashtable;)Ljava/util/Hashtable;
at
com.nokia.mid.impl.isa.util.SharedObjects.nativeSetTable(Native
Method) at
com.nokia.mid.impl.isa.util.SharedObjects.createTable(SharedObjects.java:465)
at
com.nokia.mid.impl.isa.util.SharedObjects.(SharedObjects.java:181)
at
com.nokia.mid.impl.isa.io.GeneralSharedIO.(GeneralSharedIO.java:67)
at
com.sun.midp.io.ConnectionBaseAdapter.checkForPermission(ConnectionBaseAdapter.java:236)
at
com.sun.midp.io.ConnectionBaseAdapter.openPrim(ConnectionBaseAdapter.java:205)
at
com.sun.midp.io.ConnectionBaseAdapter.openPrim(ConnectionBaseAdapter.java:178)
at
com.sun.midp.io.InternalConnector.openPrim(InternalConnector.java:254)
at
com.sun.midp.io.InternalConnector.open(InternalConnector.java:153)
at
javax.microedition.io.Connector.open(Connector.java:138)
at
javax.microedition.io.Connector.open(Connector.java:120)
at
javax.microedition.io.Connector.open(Connector.java:104)
I think that nativeSetTable() is protected or private, that's why you don't see it. And moreover nativeSetTable() is a native method, which means that it is based on native code (already compiled for a specific processor and available in a specific lib [ie. a DLL]).
UnsatisfiedLinkError means that this particular method couldn't be retrieved and executed properly.
Thrown if the Java Virtual Machine cannot find an appropriate native-language definition of a method declared native.
This means that your Java ME emulator must have missing librairies. You should try to reinstall it.
Resources :
Javadoc - UnsatisfiedLinkError
I guess you are coupling your source code with the wrong version of the nokia mid library.
It could be that your runtime classpath is using a different version of the jar where SharedObjects lives, when compared to your compile-time classpath in Eclipse. I would double-check your classpath settings.
Ok, I found one reason:
I created a test class in java to test my code, just a plain java file (with main method). And I ran it as a plain java application. Then, it doesn't work. But after I tried it in a Midlet, I didn't get the error!

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