we got a C# library that is used by our java code with JNA.
When we start it in the eclipse IDE it is working fine but when we extract it as a standalone application it does not work with the following error message:
java.lang.Error: Invalid memory access
at com.sun.jna.Native.invokeVoid(Native Method)
at com.sun.jna.Function.invoke(Function.java:374)
at com.sun.jna.Function.invoke(Function.java:323)
at com.sun.jna.Library$Handler.invoke(Library.java:236)
at com.sun.jna.Native$3.invoke(Native.java:1040)
at com.sun.proxy.$Proxy2.init(Unknown Source)
at com.test.FooImpl.init(FooImpl.java:133)
the error occurs when we try to use a method from our lib written in C#.
While remote debuggig we found out that the instance, here CSharpWrapper, is not null and has a valid proxy to the dll.
Also it does not enter the C# code. It seems that it breaks between the JNA and the C#.
this.cSharpWrapper.init();
init is a void function in the C# lib.
What could be the cause here?
Related
I am working at an EmailBot which sends lots of Emails. Today I installed Linux for developing. I am using the same IDE. But I'm getting this weird error
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
The type com.sun.net.ssl.internal.ssl.Provider is not accessible
at de.EmeldemelTV.Nice.Packi.EmailSend.main(EmailSend.java:38)
(I'm using the Java Mail API)
I am not familiar with that class, but I would check version of java. Perhaps you have different jdk on linux and this class was removed in this version.
First of all, I have a basic example of OpenCV running in a main method.
However, if I use OpenCV in a Spring Web Controller, an error is thrown.
I am getting an UnsatisfiedLinkError when running the following code inside a Tomcat Server, within STS (Spring Tool Suite), and have boiled the problem down to the following code:
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
CascadeClassifier cascadeClassifier = new CascadeClassifier();
The run configurations of both the server and the "main" application contain the VM Arguments pointing to the OpenCV DLLs:
-Djava.library.path="C:\opencv\build\java\x64;C:\opencv\build\x64\vc10\bin"
For reference, I have also included the pertinent bits of the stacktrace below:
org.springframework.web.util.NestedServletException: Handler processing failed;
nested exception is
java.lang.UnsatisfiedLinkError: org.opencv.objdetect.CascadeClassifier.CascadeClassifier_0()J
...
Caused by: java.lang.UnsatisfiedLinkError:
org.opencv.objdetect.CascadeClassifier.CascadeClassifier_0()J
at org.opencv.objdetect.CascadeClassifier.CascadeClassifier_0(Native Method)
at org.opencv.objdetect.CascadeClassifier.<init>(CascadeClassifier.java:38)
at com.immersion.test.controllers.SimpleController.createClassifier(SimpleController.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
Note: I have read in several StackOverflow threads that the main cause of the UnsatisfiedLinkError is the missing System.loadLibrary(Core.NATIVE_LIBRARY_NAME) call. This is clearly not the case here, since it is being called just above where the exception is thrown.
Same thing here.
I try what Dylan said, but did not work here.
But I added "C:\opencv\build\java\x64;C:\opencv\build\x64\vc10\bin" on my PATH variable. On my sys variables.
ps: I'm using windows.
It turns out that the default run configuration to start a Tomcat server within STS/Eclipse is essentially just a launcher for Tomcat.
This means that any VM Args that are added to the Tomcat 'run configuration' will not be transferred to the actual Tomcat instance.
On looking in tcruntime-instance.bat within the Tomcat directory (this is what ends up creating the tomcat java instance), we can see that simply by adding our intended VM Args to the JAVA_OPTS environment variable, the dlls will be available to Tomcat.
TL;DR:
So.. Simply add the the locations of the OpenCV binaries to your JAVA_OPTS environment variable:
-Djava.library.path="C:\opencv\build\java\x64;C:\opencv\build\x64\vc10\bin"
For more information on setting JAVA_OPTS for Tomcat, see this SO question.
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.
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!
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!