求高效率算法替换嵌套循环- Java

求高效算法替换嵌套循环- Java
        list1
        list2
        int i,j
        for (i = 1; i <= list1.size(); i++) { 
            Object[] obs1 = (Object[]) (list1.get(i));
            for (j = 1; j <= list2.size(); j++) { 
                 Object[] obs2 = (Object[]) (list2.get(j));
                 if(obs1[i]==obs2[j]){
                    System.out.println("相等");
                    break；
                 }
            } 
        }