B4J Question Where to put .dll used in LoadLibary() in library?

[alwaysbusy]

I'm writing a library that uses an external dll (ThinkGear.dll). In the eclipse library it is used as:

static { System.loadLibrary("thinkgear"); }

No problems so far. When I now run it, I'll get the following error:

java.lang.ExceptionInInitializerError
Caused by: java.lang.RuntimeException: java.lang.UnsatisfiedLinkError: no thinkgear in java.library.path
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:113)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:82)
    at b4j.example.main.<clinit>(main.java:16)
Caused by: java.lang.UnsatisfiedLinkError: no thinkgear in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1886)
    at java.lang.Runtime.loadLibrary0(Runtime.java:849)
    at java.lang.System.loadLibrary(System.java:1088)
    at com.AB.ABThinkGear.ABThinkGear.<clinit>(ABThinkGear.java:12)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:190)
    at anywheresoftware.b4a.shell.Shell.getCorrectClassName(Shell.java:451)
    at anywheresoftware.b4a.shell.Shell.createObject(Shell.java:438)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:239)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:156)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    ... 2 more
Exception in thread "main"

Makes sense, I haven't put the dll anywhere. I would suspect it needs to be in the \B4J\Objects\shell\bin\classes\b4j\example folder. I made it read only, but then I can't compile the project anymore.

Is there a special folder I can use?

Cheers,

Alain

 

[Erel]

Try this:
Put the file in the Objects folder. This is equivalent to File.DirApp.

Now call

System.load(anywheresoftware.b4a.objects.streams.File.getDirApp & "/thinkgear.dll"); //load not loadLibrary.

 

[alwaysbusy]

Closer, but no sigar!

I can compile, but not run:

Program started.
java.lang.RuntimeException: java.lang.UnsatisfiedLinkError: com.AB.ABThinkGear.ABThinkGear.TG_GetDriverVersion()I
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:113)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:82)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
    at b4j.example.main.start(main.java:35)
    at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:319)
    at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:219)
    at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:182)
    at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:179)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:179)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:76)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:17)
    at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:67)
    at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.UnsatisfiedLinkError: com.AB.ABThinkGear.ABThinkGear.TG_GetDriverVersion()I
    at com.AB.ABThinkGear.ABThinkGear.TG_GetDriverVersion(Native Method)
    at com.AB.ABThinkGear.ABThinkGear.GetDriverVersion(ABThinkGear.java:95)
    at b4j.example.main._appstart(main.java:74)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:558)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:224)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:156)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    ... 14 more

Attached is the B4J project and the java library project. In my view, this should be a very simple 'wrap'. The GetDriverVersion() function shuold work without having the hardware. I did this wrapper in Xojo (using declares) but thought this could be a grood project to test out B4J

Cheers,

Alain

 

[Erel]

I'm getting the same results as you. The library is found and loaded (otherwise the error will be different).

Where did you find this Java wrapper?

Seems like there is another option which is to communicate through sockets: http://developer.neurosky.com/docs/doku.php?id=which_api_is_right_for_me

 

[alwaysbusy]

I found several versions around. I think this one is based on the Official SDK of NeuroSky.

Here are some versions I have:

ThinkGear1: using jna to access the dll (could not get it working as it had problems finding the jna lib)
ThinkGear2: The official one I based mine on
ThinkGearSocket3: The one using sockets (like you suggested), written for Processing (is java like)

I was just trying it out like this at it seemed straightforward (and very similar to use as the xojo one). But I guess I will have to try to get a go with the third option anyway.

 

[Thuong]

Dear
I code static { System.load("/thinkgear.dll"); } and compile is ok to B4A library
It is correct ?

 

[alwaysbusy]

No. B4A cannot work with Windows dlls. This was me trying to build a library for B4J, but I've never got it working. For B4A, you'll need the code I've PM'ed you, using the .jar files. 'see the @DependsOn()' lines.

 

[lindomar]

I'm having the same problem to load a DLL library...
Can you help me?

 

[Erel]

You cannot work directly with dlls. You need to create a Java wrapper that will call the native dll with jni calls.

 

[lindomar]

Plese look here...
https://www.b4x.com/android/forum/threads/bass-for-windows-b4j-help.57458/