Compositino vs Inheritence in Java

fisk.java

/**
 * Djur is a thing that can be hungrig. By doing mumsa a Djur can become
 * !hungrig.
 */
public class Djur {
    private boolean hungrig = true;

    public boolean isHungrig() {
        return this.hungrig;
    }

    public boolean setHungrig(boolean hungrig) {
        this.hungrig = hungrig;
    }

    public void mumsa(Djur other) {
        this.tugga(other);
        this.smaska(other);
        this.svalja(other);
        this.setHungrig(false);
    }

    private void tugga(Djur other) {
        ...
    }

    private void smaska(Djur other) {
        ...
    }

    private void svalja(Djur other) {
        ...
    }
}


/**
 * Fisk by inheritence. Fisk knows how to mumsa because Fisk isa Djur.
 */
public class Fisk1 extends Djur {}


/**
 * Fisk by composition. Fisk knows how to mumsa because Fisk has access to an
 * object that can perform the mumsa for it.
 */
public class Fisk2 {
    public Fisk(Djur me) {
        this.me =  me;
    }

    public void mumsa(Djur other) {
        this.me.mumsa(other);
    }

    public boolean isHungrig() {
        return this.me.isHungrig();
    }
}