ShowingHowToUseInterfacesAsListeners

//Holds all the methods to be used.
//StatusChangeListener.java
public interface StatusChangeListener
{
    void atkChanged();
    void defChanged();
    void levelChanged();
    int getCurrentATK();
    int getCurrentDEF();
    int getCurrentLevel();
}

//This next one is just an example of one way to use said methods above
//StatusChecker.java
public class StatusChecker implements StatusChangeListener {

    public StatusChecker() {
        // TODO Auto-generated constructor stub
    }

    @Override
    public void atkChanged()
    {
        // TODO Auto-generated method stub
        System.out.println("ATK Changed!");
    }

    @Override
    public void defChanged()
    {
        // TODO Auto-generated method stub
        System.out.println("DEF Changed!");
    }

    @Override
    public void levelChanged()
    {
        // TODO Auto-generated method stub
        System.out.println("Level Changed!");
    }

    @Override
    public int getCurrentATK()
    {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public int getCurrentDEF()
    {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public int getCurrentLevel()
    {
        // TODO Auto-generated method stub
        return 0;
    }


}

//Next is our target the card class
//CardTester.java
public class CardTester
{

    private int originalatk, originaldef, originallevel, currentatk, currentdef, currentlevel;
    StatusChangeListener sclcheck;
    /**
     *
     */
    public CardTester(StatusChangeListener checker,int atk, int def, int level)
    {
        //Word of advice: Make sure your personal listeners are up top in constructor so you do get null errors if you're using methods in it. >_>
        sclcheck = checker;
        setOriginalatk(atk);
        setOriginaldef(def);
        setOriginallevel(level);
        setCurrentatk(atk);
        setCurrentdef(def);
        setCurrentlevel(level);
        System.out.println("Card Created!");
    }
    /**
     * @return the originalatk
     */
    public int getOriginalatk()
    {
        return originalatk;
    }
    /**
     * @param originalatk the originalatk to set
     */
    public void setOriginalatk(int oatk)
    {
        if(originalatk != oatk)
        {
            sclcheck.atkChanged();
        }
        this.originalatk = oatk;

    }
    /**
     * @return the originaldef
     */
    public int getOriginaldef()
    {
        return originaldef;
    }
    /**
     * @param originaldef the originaldef to set
     */
    public void setOriginaldef(int odef)
    {
        if(originaldef != odef)
        {
            sclcheck.defChanged();
        }
        this.originaldef = odef;

    }
    /**
     * @return the originallevel
     */
    public int getOriginallevel()
    {
        return originallevel;
    }
    /**
     * @param originallevel the originallevel to set
     */
    public void setOriginallevel(int olevel)
    {
        if(originallevel != olevel)
        {
            sclcheck.levelChanged();
        }
        this.originallevel = olevel;

    }
    /**
     * @return the currentatk
     */
    public int getCurrentatk()
    {
        return currentatk;
    }
    /**
     * @param currentatk the currentatk to set
     */
    public void setCurrentatk(int catk)
    {
        if(currentatk != catk)
        {
            sclcheck.atkChanged();
        }
        this.currentatk = catk;

    }
    /**
     * @return the currentdef
     */
    public int getCurrentdef()
    {
        return currentdef;
    }
    /**
     * @param currentdef the currentdef to set
     */
    public void setCurrentdef(int cdef)
    {
        if(currentdef != cdef)
        {
            sclcheck.defChanged();
        }
        this.currentdef = cdef;
    }
    /**
     * @return the currentlevel
     */
    public int getCurrentlevel()
    {
        return currentlevel;
    }
    /**
     * @param currentlevel the currentlevel to set
     */
    public void setCurrentlevel(int clevel)
    {
        if(currentlevel != clevel)
        {
            sclcheck.levelChanged();
        }
        this.currentlevel = clevel;
    }

}

//Last is our main class.  Found out the hard way that you should never try to use your main as what is going into the listener holder of a class since you get an annoying error to do with static methods.
//MainClass1.java

import java.util.Random;

public class MainClass1 //implements StatusChangeListener
{


    /**
     * @param args
     */
    public static void main(String[] args)
    {
        Random rand = new Random();
        StatusChecker sctest = new StatusChecker();
        // TODO Auto-generated method stub
        //System.out.println("Card Created!");
        CardTester changetest = new CardTester(sctest, 1000, 1000, 12);
        System.out.println("Status Checking Test Ready!");
        int atkhold = 0;
        while(changetest.getCurrentatk() <= 10000)
        {
            atkhold += 1000;
            changetest.setCurrentatk(rand.nextInt(atkhold));
            System.out.println("ATK is now: " + changetest.getCurrentatk());
        }
    }

}