list去重并合并的问题

放set里，如果有顺序就linkedHaseSet

ArrayList newList=new ArrayList ();
ArrayList newList2=new ArrayList ();
ArrayList newList3=new ArrayList ();
newList2.add(0,"10583601");
newList2.add(1,"10584601");
newList3.add(0,"10583601");
newList3.add(1,"10583611");

    for(int i = 0; i < newList3.size(); i++) {
                    //判断newList2中有没有newList2里重复数据，true：将原来删除，修改+1库存  false：直接add
                    //假设你这里的库存数量是 2+2 =4的要求，取消掉注释，将原来注释掉 
        if(newList2.contains(newList3.get(i))) {
            String test = newList3.get(i);
            int t=Integer.parseInt(test);
            newList2.remove(test);
            newList2.add(String.valueOf(t+1));
                            //int s=Integer.parseInt(test.substring(test.length()-1,test.length()));
           //newList2.add(String.valueOf(t+s));
        }else {
            newList2.add(newList3.get(i));
        }
    }
    newList.addAll(newList2);
    for (String list :newList) {
        System.out.println(list);
    }