removeAll()不移除对象

Question

我有两个自创建类的objects.After比较数组列表，我正在从这两个类中删除公共对象，并准备了获取公共elements.After的方法--查找公共元素--我通过调用removeAll()方法删除公共元素，但它不是删除该元素。我以前使用过这个方法，但从未得到过htis类型的error.Here是我的代码：

public void SynchphoneBookwithDB() {
    //phone contacts
    ArrayList < Contacts > phone_contacts = CommonUtility.getAllContacts(ctx);
    Log.e("SynchphoneBookwithDb", "phonebooksize" + phone_contacts.size());
    //get data base contacts 
    ArrayList < Contacts > db_contacts = UserService.getUserServiceInstance(ctx).getNameNumberIdIsmycontactIsBlockedFromContatcsTable();
    Log.e("SynchphoneBookwithDb", "DBSIZE" + db_contacts.size());
    //get common contacts
    ArrayList < Contacts > common_contacts = getCommonContacts(phone_contacts, db_contacts, false);
    Log.e("SynchphoneBookwithDb", "common_contacts" + common_contacts.size());
    //not operation on common numbers so remove them 
    phone_contacts.removeAll(common_contacts);
    db_contacts.removeAll(common_contacts);

    //remained in phone must be added to db 
    Log.e("SynchphoneBookwithDb", "afetr removing contacts phonebooksize" + phone_contacts.size());

    Log.e("SynchphoneBookwithDb", "after removing contacts DBSIZE" + db_contacts.size());

}

下面是我获取公共元素的方法：

public ArrayList < Contacts > getCommonContacts(ArrayList < Contacts > referenced, ArrayList < Contacts > other, Boolean insertInDb) {
    //       Log.d("Inside common contacts","start"); 
    ArrayList < Contacts > commonArrayList = new ArrayList < Contacts > ();
    int count_ref = referenced.size();

    for (int i = 0; i < count_ref; i++) {
        int count_other = other.size();
        for (int j = 0; j < count_other; j++) {
            if (referenced.get(i).getNumber().equals(other.get(j).getNumber())) {
                commonArrayList.add(other.get(j));
                if (insertInDb) { //insert from server as it is 
                    other.get(j).setIsmycontact(true);
                    long k = UserService.getUserServiceInstance(ctx).addInContatcs(other.get(j));
                }

            }
        }
    }

    return commonArrayList;
}

Answer 1

你的目标似乎不平等！只是他们的号码场。

重写联系人类的相等方法，并使用它来比较它们。

ArrayList#removeAll(收藏)使用List#remove(对象)，它使用相等

更正式地说，删除索引i最低的元素，以便(o==null？get(i)==null :o.equals(get(I)(如果存在这样的元素)。