OSGI Unresolved requirement: Import-Package: com.pi4j.io.gpio

Question

I want to write an OSGI Bundle (Eclipse SmartHome Binding) for the GPIO's of a Raspberry Pi.
For the GPIO's i need to include the Pi4J libraries. I added them into a lib folder in my project folder and added the pi4j-core.jar to my Build Path.

This is my code:

/**
 * Copyright (c) 2014 openHAB UG (haftungsbeschraenkt) and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.statusgpio.handler;

import static org.openhab.binding.statusgpio.StatusGPIOBindingConstants.*;

import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

import org.eclipse.smarthome.core.library.types.StringType;
import org.eclipse.smarthome.core.thing.ChannelUID;
import org.eclipse.smarthome.core.thing.Thing;
import org.eclipse.smarthome.core.thing.binding.BaseThingHandler;
import org.eclipse.smarthome.core.types.Command;
//import org.slf4j.Logger;
//import org.slf4j.LoggerFactory;

import com.pi4j.io.gpio.GpioController;
import com.pi4j.io.gpio.GpioFactory;
import com.pi4j.io.gpio.GpioPinDigitalInput;
import com.pi4j.io.gpio.PinPullResistance;
import com.pi4j.io.gpio.RaspiPin;
import com.pi4j.io.gpio.event.GpioPinDigitalStateChangeEvent;
import com.pi4j.io.gpio.event.GpioPinListenerDigital;

/**
 * The {@link StatusGPIOHandler} is responsible for handling commands, which are
 * sent to one of the channels.
 * 
 * @author Arjuna W. - Initial contribution
 */
public class StatusGPIOHandler extends BaseThingHandler {

    ScheduledFuture<?> refreshJob;

    public StatusGPIOHandler(Thing thing) {
        super(thing);
    }

    @Override
    public void initialize() {
        // TODO Auto-generated method stub
        super.initialize();

        startAutomaticRefresh();
    }

    @Override
    public void handleCommand(ChannelUID channelUID, Command command) {
        // TODO Auto-generated method stub

        // do nothing ;)
    }

    private void startAutomaticRefresh() {

        final GpioController gpio = GpioFactory.getInstance();

        // provision gpio pin #02 as an input pin with its internal pull down
        // resistor enabled
        final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(
                RaspiPin.GPIO_02, PinPullResistance.PULL_DOWN);

        // create and register gpio pin listener
        myButton.addListener(new GpioPinListenerDigital() {
            @Override
            public void handleGpioPinDigitalStateChangeEvent(
                    GpioPinDigitalStateChangeEvent event) {
                // display pin state on console
                updateState(new ChannelUID(getThing().getUID(), CHANNEL_LOADING_STATE), new StringType(event.getState().toString()));

            }

        });

            try {
                for (;;) {
                Thread.sleep(1000);
                }

            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    }   

}

The Class has no problem to find the Pi4J imports and export to a jar is also no problem. Only if I run it directly in the Eclipse OpenHab_runtime I geht the Error:

!Validation: The following Problems were detected: org.openhab.binding.statusgpio Missing Constraint: Import-Package: com.pi4j.io.gpio; version="0.0.0"

When I start the OSGI Bundle on my Raspberry Pi (and on my Win PC) I get the message:

start 92

gogo: BundleException: Could not resolve module: org.openhab.binding.statusgpio [92]
Unresolved requirement: Import-Package: com.pi4j.io.gpio

I think I have to do something more with the Bundle to let OSGI find the Pi4J Libs???

Thanks for Help.

Answer 1

I found my own mistake:
I thought I hat to add "com.pi4j.io.gpio" to the includes in the Manifest file, but I don't want to import it from other OSGI Bundles, I want to import it from an alteady imported JAR. So I just had to delete this line and everything worked.
Edit:
I found the answer here: https://github.com/ECF/RaspberryPI/tree/master/bundles/com.pi4j
This is my manifest.mf:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: OutputGPIO Binding
Bundle-SymbolicName: org.openhab.binding.outputgpio;singleton:=true
Bundle-Vendor: openHAB
Bundle-Version: 2.0.0.qualifier
Bundle-RequiredExecutionEnvironment: JavaSE-1.7
Bundle-ClassPath: lib/pi4j-core.jar,
 lib/pi4j-device.jar,
 lib/pi4j-gpio-extension.jar,
 lib/pi4j-service.jar,
 .
Import-Package: com.google.common.collect,
 org.eclipse.smarthome.config.core,
 org.eclipse.smarthome.config.discovery,
 org.eclipse.smarthome.core.library.types,
 org.eclipse.smarthome.core.thing,
 org.eclipse.smarthome.core.thing.binding,
 org.eclipse.smarthome.core.types,
 org.slf4j
Service-Component: OSGI-INF/*
Export-Package: org.openhab.binding.outputgpio,
 org.openhab.binding.outputgpio.handler