Bubble sort

public void seradPodleCasu() {
            if (this.zavodnici == null) return;

            for (int i = 0; i < this.zavodnici.length - 1; i++) {
                for (int j = 0; j < this.zavodnici.length - i - 1; j++) {
                    if (this.zavodnici[j].getCelkovyCas() > this.zavodnici[j+1].getCelkovyCas()) {
                        Zavodnik pom = this.zavodnici[j];
                        this.zavodnici[j] = this.zavodnici[j+1];
                        this.zavodnici[j+1] = pom;
                    }
                }
            }
        }