Java HashSet<>:如果HashSet包含非指定的值，则返回false [英] Java HashSet<> : Return false if HashSet contains values other than specified

问题描述

因此，我从中提取了一个字符串列表，例如{"ADD"，"DEL"，"CHG"，"DEL"，"NA"，"ADD"，"BLAH"，"YAK"，....}JSON请求并将其传递到哈希集上，以避免重复.如果HashSet除了"ADD"，"NA"或"both"以外的其他值，如何使我的函数返回false?任何帮助.

So I extracted a List of Strings e.g {"ADD","DEL","CHG","DEL","NA","ADD","BLAH","YAK",.... } from JSON Request and passed them onto a hashset to avoid duplicates. How do I get my function to return false if the HashSet has anything else other than "ADD" or "NA" or "both" ? Any Help Appreciated.

更新:在我的代码中，我只是在所有我可能认为不需要的值周围添加了一个NOT条件.我需要一个更有效的解决方案.

Update: In my code, I just added a NOT condition around all those values that I can possibly think of that I do not require.I need a more effective solution.

也:我的true()条件是ADD必须始终存在，而NA是可选的.除了必需的"ADD"和可选的"NA"之外，没有其他值必须存在.例如:

Also: My true() condition is that ADD must present at all times while NA is optional.No other values must be present other than the mandatory "ADD" and the optional "NA" . eg:

1. {ADD}返回true
2. {ADD，NA}返回true
3. {ADD，DEL}返回false
4. {DEL，YAK}返回false，等等.

下面的代码片段没有此项检查，我正在寻找最少冗长的最佳解决方案.

The below snippet doesn't have this check and i am looking for the best solution with least verbosity.

这是代码段.字符串列表作为参数传递给isAddOrNa().

Here's the snippet. The List of Strings are passed as an argument to isAddOrNa().

private boolean isAddOrNa(List<AllActions> allActions) {
    Set<String> actions = new HashSet<>();
    for (com.demo.Action action : allActions) {
        actions.add(action.getName());
    }
    return ((actions.size() <= 2) && (actions.contains("ADD") || actions.contains("NA"))) &&
            !(actions.contains("DEL") || actions.contains("CHG") || actions.contains("BLAH") || actions.contains("YAK"));
}

推荐答案

private boolean isAddOrNa(List<AllActions> allActions) {
    Set<String> actions = new HashSet<>();
    for (com.demo.Action action : allActions) {
        actions.add(action.getName());
    }
    return actions.contains("ADD") && ((actions.contains("NA") && actions.size() ==2) || (!actions.contains("NA") && actions.size() ==1));
}

最小化条件.这有帮助吗?

Minimized the conditions. Does this help?

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