B4J Question JavaObject and AdditionalJar

[JeromeLamy]

Hello,
I am trying to use an external library in my B4J application.
I am faced with a crash when trying to instantiate the object.

The external library is documented here : http://nyholku.github.io/purejavahidapi/javadoc/index.html
The Jar is available at https://github.com/nyholku/purejavahidapi

I have copied the file purejavahidapi.jar in a local folder, and referenced that folder in B4J settings for the additional libraries.

Source code is simple at this stage, I am just trying to read the version, before trying to enumerate.

#Region Project Attributes
    #MainFormWidth: 600
    #MainFormHeight: 400
#End Region

#AdditionalJar: purejavahidapi

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.Show

    Dim s As String
    s = GetVersion
    Log( s )
End Sub

Sub GetVersion As String
   Dim jo As JavaObject
   Return jo.InitializeStatic("purejavahidapi.PureJavaHidApi").RunMethod("getVersion", Null )
End Sub

As soon as I run the application I get :

Waiting for debugger to connect...
Program started.
java.lang.NoClassDefFoundError: com/sun/jna/Platform
    at purejavahidapi.PureJavaHidApi.<clinit>(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at anywheresoftware.b4j.object.JavaObject.getCorrectClassName(JavaObject.java:273)
    at anywheresoftware.b4j.object.JavaObject.InitializeStatic(JavaObject.java:74)
    at b4j.example.main._getversion(main.java:96)
    at b4j.example.main._appstart(main.java:76)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:612)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:229)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:90)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
    at b4j.example.main.start(main.java:36)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$163(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$149(WinApplication.java:191)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: com.sun.jna.Platform
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 31 more
java.lang.RuntimeException: java.lang.NoClassDefFoundError: com/sun/jna/Platform
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:114)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:90)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
    at b4j.example.main.start(main.java:36)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$163(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$149(WinApplication.java:191)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: com/sun/jna/Platform
    at purejavahidapi.PureJavaHidApi.<clinit>(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at anywheresoftware.b4j.object.JavaObject.getCorrectClassName(JavaObject.java:273)
    at anywheresoftware.b4j.object.JavaObject.InitializeStatic(JavaObject.java:74)
    at b4j.example.main._getversion(main.java:96)
    at b4j.example.main._appstart(main.java:76)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:612)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:229)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    ... 12 more
Caused by: java.lang.ClassNotFoundException: com.sun.jna.Platform
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 31 more

What would be the correct syntax for this simple call ?

Thanks,

Jerome

 

[Daestrum]

You need to add one more jar

#AdditionalJar: jna-4.2.1

As it appears the purejavahidapi relies on jna to work.
(I tried earlier version of jna and it didn't work)

Your sample code reports the version as 0.0.10

 

[JeromeLamy]

Thanks for the help, it works as a charm !

Summary :
I copied the jna-4.0.0.jar included into that external library package in the additional library folder, next to purejavahidapi.jar
and added the two lines

#AdditionalJar: purejavahidapi
#AdditionalJar: jna-4.0.0

and I can now access hid devices.