類型不匹配：無法從元素類型對象轉換為列表

Question

我收到此錯誤：“ Type mismatch: cannot convert from element type Object to List" in "subLists" “ Type mismatch: cannot convert from element type Object to String"在"accList"

碼：

ArrayList subLists = new ArrayList();

for (List accList : subLists) {
        service.submit(() -> {
            for (String account : accList) {
                accounts.remove(account);
                String[] split = account.split(":");
                String email = split[0];
                String password = split[1];
                AuthResult result = null;

Answer 1

您沒有指定不同lists的對象類型，您需lists ，程序不會猜測：

List<List<String>> subLists = new ArrayList<>();  

for (List<String> accList : subLists) {
    service.submit(() -> {
        for (String account : accList) {
// ...

另外，與Implementations相比，更好地使用Interfaces來存儲變量，更易於更新（ List<List<String>> rather than ArrayList<List<String>>