Examples - "Could not find or load main class"

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Dennis Meade

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Apr 16, 2015, 12:46:11 PM4/16/15
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I'm having a problem with LedExample and SerialExample on a
Beaglebone Black. Each example produces the following error
message and goes no further. I can not find anything that would
suggest why this is happening. 

"Could not find or load main class"


I attempted to fix the problem by moving all the code from "main"
in LedExample which you can see below. This resulted in an
"Array Out of Bounds Exception". The stack trace follows the code.
The same thing happened with SerialExample.

My CLASSPATH contains: bulldog.beagleboneblack.hardfp-0.1.0

So, is this an error on my part or a bug.

Thank you for looking at this.

Dennis Meade


====================LedExample==========================


import java.io.IOException;

import org.bulldog.beagleboneblack.BBBNames;
import org.bulldog.core.gpio.Pwm;
import org.bulldog.core.platform.Board;
import org.bulldog.core.platform.Platform;
import org.bulldog.core.util.BulldogUtil;
import org.bulldog.devices.led.Led;

public class LedExample {
    
    private static LedExample ledExample = null;
    
    public LedExample() {
      
        // Get your platform
        final Board board = Platform.createBoard();

        // Get a PWM
        Pwm pwm = board.getPin( BBBNames.PWM_P8_13 ).as( Pwm.class );

        // Construct the LED with it
        Led led = new Led( pwm );

        led.setBrightness( 1.0 );
        BulldogUtil.sleepMs( 1000 );

        led.setBrightness( 0.5 );
        BulldogUtil.sleepMs( 1000 );

        for ( int i = 0; i < 5; i++ ) {
            led.fadeIn( 1000 );
            led.fadeOut( 1000 );
        }
        
    }

    public static void main( String... args ) throws IOException {

        ledExample = new LedExample();
 
    }

}



===========================================================



root@arm:/usr/src/bulldog# java LedExample

java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.isHdmiEnabled(BeagleBoneBlack.java:298)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createPins(BeagleBoneBlack.java:137)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:31)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.isEmmcEnabled(BeagleBoneBlack.java:303)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createPins(BeagleBoneBlack.java:141)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:31)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.io.BBBUartPort.isSlotLoaded(BBBUartPort.java:46)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPort(BeagleBoneBlack.java:240)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPorts(BeagleBoneBlack.java:247)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createBuses(BeagleBoneBlack.java:222)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:32)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.io.BBBUartPort.isSlotLoaded(BBBUartPort.java:46)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPort(BeagleBoneBlack.java:240)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPorts(BeagleBoneBlack.java:248)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createBuses(BeagleBoneBlack.java:222)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:32)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.io.BBBUartPort.isSlotLoaded(BBBUartPort.java:46)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPort(BeagleBoneBlack.java:240)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPorts(BeagleBoneBlack.java:249)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createBuses(BeagleBoneBlack.java:222)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:32)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.io.BBBUartPort.isSlotLoaded(BBBUartPort.java:46)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPort(BeagleBoneBlack.java:240)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPorts(BeagleBoneBlack.java:250)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createBuses(BeagleBoneBlack.java:222)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:32)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.io.BBBUartPort.isSlotLoaded(BBBUartPort.java:46)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPort(BeagleBoneBlack.java:240)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPorts(BeagleBoneBlack.java:251)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createBuses(BeagleBoneBlack.java:222)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:32)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.io.BBBUartPort.isSlotLoaded(BBBUartPort.java:46)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPort(BeagleBoneBlack.java:240)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createSerialPorts(BeagleBoneBlack.java:252)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createBuses(BeagleBoneBlack.java:222)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:32)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.isHdmiEnabled(BeagleBoneBlack.java:298)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createProperties(BeagleBoneBlack.java:256)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:33)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.isEmmcEnabled(BeagleBoneBlack.java:303)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.createProperties(BeagleBoneBlack.java:260)
        at org.bulldog.beagleboneblack.BeagleBoneBlack.<init>(BeagleBoneBlack.java:33)
        at org.bulldog.beagleboneblack.BeagleBoneBlackBoardFactory.createBoard(BeagleBoneBlackBoardFactory.java:17)
        at org.bulldog.core.platform.Platform.createBoard(Platform.java:13)
        at LedExample.<init>(LedExample.java:18)
        at LedExample.main(LedExample.java:41)
-- listing properties --
beagleboneblack.dogtag=rcn-ee.net console Debian Image 2015-...
java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.readSlots(BBBSysFs.java:65)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getSlotNumber(BBBSysFs.java:31)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.createSlotIfNotExists(BBBSysFs.java:95)
        at org.bulldog.beagleboneblack.gpio.BBBPwm.setupImpl(BBBPwm.java:55)
        at org.bulldog.core.gpio.base.AbstractPinFeature.setup(AbstractPinFeature.java:43)
        at org.bulldog.core.gpio.Pin.activateFeature(Pin.java:385)
        at org.bulldog.core.gpio.Pin.as(Pin.java:164)
        at LedExample.<init>(LedExample.java:21)
        at LedExample.main(LedExample.java:41)
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManager(BBBSysFs.java:23)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.getCapeManagerSlots(BBBSysFs.java:27)
        at org.bulldog.beagleboneblack.sysfs.BBBSysFs.createSlotIfNotExists(BBBSysFs.java:96)
        at org.bulldog.beagleboneblack.gpio.BBBPwm.setupImpl(BBBPwm.java:55)
        at org.bulldog.core.gpio.base.AbstractPinFeature.setup(AbstractPinFeature.java:43)
        at org.bulldog.core.gpio.Pin.activateFeature(Pin.java:385)
        at org.bulldog.core.gpio.Pin.as(Pin.java:164)
        at LedExample.<init>(LedExample.java:21)
        at LedExample.main(LedExample.java:41)
root@arm:/usr/src/bulldog#


Dennis Meade

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Apr 17, 2015, 5:30:35 PM4/17/15
to libbu...@googlegroups.com
As I understand it, the reason for the ArrayOutOfBounds Exception  is a missing file in my version of Debian (3.14.33). BBBSysFs.getCapeManager() is looking for a file ""/sys/devices/bone_capemgr" which does not exist in my copy of Debian.

I'm not sure what this means. Should the file be there? Is my interpretation correct?

Datenheld

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Apr 18, 2015, 3:59:49 AM4/18/15
to libbu...@googlegroups.com
Hi Dennis,

this is most likely due to your linux kernel version and distribution.

See this issue:

I won't fix it.

Dennis Meade

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Apr 18, 2015, 4:29:32 AM4/18/15
to libbu...@googlegroups.com
Thank you for your reply, Datenheld. I guess I will be learning more about the Linux file system.
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