LogicGates/eu.heili/LogicGate.java

import java.util.ArrayList;
import java.util.Arrays;

public abstract class LogicGate {
    private final ArrayList<DigitalInput> inputs = new ArrayList<>();

    public LogicGate(final int inputnr) {
        for (int i = 0; i < inputnr; i++) {
            inputs.add(new DigitalInput()); // generate new objects for new inputs
        }
    }

    public LogicGate(final DigitalInput... inputvals) {
        inputs.addAll(Arrays.asList(inputvals));
    }

    /**
     * validate gate output.
     *
     * @return validated output
     */
    public abstract boolean getOutput();

    public DigitalInput getInput(final int nr) {
        if (nr >= getInputNumber())
            throw (new InputOutOfBoundsException());
        return inputs.get(nr);
    }

    public int getInputNumber() {
        return inputs.size();
    }

    public void addInput(final DigitalInput in) {
        inputs.add(in);
    }
}