B4J Question pi4j question

[madru]

Hi, has somebody played with pi4j recently ?

Sub GetBus(BusNumber As Int) As JavaObject
    Dim factory As JavaObject
    Return factory.InitializeStatic("com.pi4j.io.i2c.I2CFactory").RunMethodJO("getInstance", Array As Object(BusNumber))
End Sub

returns

java.lang.ClassNotFoundException: com.pi4jj$io$i2c$I2CFactory

 

[Erel]

The error message and the code do not match. Post the code that you are running.

 

[madru]

that's what I get....

Sub AppStart (Args() As String)
    bus = i2c.GetBus(1)
    Log(bus)
End Sub

Sub GetBus(BusNumber As Int) As JavaObject
 
    Dim factory As JavaObject
    Return factory.InitializeStatic("com.pi4j.io.i2c.I2CFactory").RunMethodJO("getInstance", Array As Object(BusNumber))
 
End Sub

Waiting for debugger to connect...
Program started.
Error occurred on line: 8 (i2c)
java.lang.ClassNotFoundException: com.pi4j$io$i2c$I2CFactory
    at anywheresoftware.b4j.object.JavaObject.getCorrectClassName(JavaObject.java:289)
    at anywheresoftware.b4j.object.JavaObject.InitializeStatic(JavaObject.java:75)
    at b4j.example.i2c._getbus(i2c.java:39)
    at b4j.example.main._appstart(main.java:74)
    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:498)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:632)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:234)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:167)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.ja
va:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:91)
    at anywheresoftware.b4a.shell.ShellBA.raiseEvent2(ShellBA.java:98)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:78)
    at b4j.example.main.main(main.java:29)
Program terminated (StartMessageLoop was not called).

 

[Erel]

The error in the first post had an extra 'j'.

The class is inside pi4j-core. You are doing something wrong.

 

[madru]

Don’t think so, the old „driver“ I did https://www.b4x.com/android/forum/threads/raspberry-b4j-i2c-hd44780-lcd-driver.61123/ does also not work anymore.

Something must have changed.....

 

[roberto64]

Hello, i have been trying libreia PI4J for days, but after many attempts and many tests i discover that if i use rasberry PI4 java ver.11.0.7 already installed it works, i still have to try java ver.14.0, in versions PI4J 1.2 and 1.3 give errors, I downloaded the ver.2 PI4j and I put only "pi4j-core.jar" and I remove the PI4J library the problem no longer exists, in reference to the code "B4J_LCD_BigNumber" all right up to row 56 of the lcd class with i2c call in writing it gives me this error, I have been trying for days to write in my 1602A LCD which uses "0x27" as a device, but nothing.
1 question qule java version and compatible with PI4J.
2) someone operated the LCD of the Freenova LCD 1602A kit.
3) Any help?
regards

Waiting for debugger to connect...
Program started.
AppStart :: Start
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.pi4j.io.file.LinuxFile (file:/home/pi/tempjars/AsyncInput2) to field java.nio.Buffer.address
WARNING: Please consider reporting this to the maintainers of com.pi4j.io.file.LinuxFile
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Error occurred on line: 40
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:132)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:676)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:240)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:
167)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:91)
at anywheresoftware.b4a.shell.ShellBA.raiseEvent2(ShellBA.java:98)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:78)
at b4j.example.main.main(main.java:29)
Caused by: java.lang.NoClassDefFoundError: sun/misc/SharedSecrets
at com.pi4j.io.file.LinuxFile.getFileDescriptor(LinuxFile.java:213)
at com.pi4j.io.file.LinuxFile.ioctl(LinuxFile.java:101)
at com.pi4j.io.i2c.impl.I2CBusImpl.selectBusSlave(I2CBusImpl.java:289)
at com.pi4j.io.i2c.impl.I2CBusImpl.runBusLockedDeviceAction(I2CBusImpl.java:256)
at com.pi4j.io.i2c.impl.I2CBusImpl.writeByteDirect(I2CBusImpl.java:167)
at com.pi4j.io.i2c.impl.I2CDevic
eImpl.write(I2CDeviceImpl.java:90)
... 20 more
Caused by: java.lang.ClassNotFoundException: sun.misc.SharedSecrets
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 26 more

 

[Erel]

Something must have changed.....

Only you can know what changed in your environment.