java - 使用最合适的数据结构简化嵌套的 if-else 结构

Question

我有一个嵌套的 if-else 块，其中存在一系列需要以特定顺序执行的条件。下面是代码示例。

        Map<String, String> DataHashMap = new HashMap<>();
        String SPECIES = "SPECIES";
        String NATIONALITY = "NATIONALITY";
        String STATE = "STATE";
        String GENDER = "GENDER";
        String OCCUPATION = "OCCUPATION";
        String HUMAN = "HUMAN";
        String AMERICAN = "AMERICAN";
        String WASHINGTON = "WASHINGTON";
        String FEMALE = "FEMALE";
        String BANKER = "BANKER";

        DataHashMap.put(SPECIES, HUMAN);
        DataHashMap.put(NATIONALITY, AMERICAN);
        DataHashMap.put(STATE, WASHINGTON);
        DataHashMap.put(GENDER, FEMALE);
        DataHashMap.put(OCCUPATION, BANKER);

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

        if (HUMAN.equals(DataHashMap.get(SPECIES))) {
            EligibilityList.add("H");
            if (AMERICAN.equals(DataHashMap.get(NATIONALITY))) {
                EligibilityList.add("A");
                if (WASHINGTON.equals(DataHashMap.get(STATE))) {
                    EligibilityList.add("W");
                    if (FEMALE.equals(DataHashMap.get(GENDER))) {
                        EligibilityList.add("F");
                        if (BANKER.equals(DataHashMap.get(OCCUPATION))) {
                            EligibilityList.add("B");
                        } else {
                            EligibilityList.add("NB");
                        }
                    } else {
                        EligibilityList.add("NF");
                    }
                } else {
                    EligibilityList.add("NW");
                }
            } else {
                EligibilityList.add("NA");
            }
        } else {
            EligibilityList.add("NH");
        }
        System.out.println(EligibilityList);

我需要使用最合适和最有效的数据结构来修改嵌套的 if-else 结构。任何人都可以建议一种可以有效完成上述工作的数据结构吗？常量、映射和列表需要保持原样(映射是输入，列出输出)。 if-else 逻辑块可以修改

Answer 1

我会将每个条件放在一个列表中进行处理。

        String SPECIES = "SPECIES";
        String NATIONALITY = "NATIONALITY";
        String STATE = "STATE";
        String GENDER = "GENDER";
        String OCCUPATION = "OCCUPATION";
        String HUMAN = "HUMAN";
        String AMERICAN = "AMERICAN";
        String WASHINGTON = "WASHINGTON";
        String FEMALE = "FEMALE";
        String BANKER = "BANKER";
        
        Map<String, String> DataHashMap = new HashMap<>();
        DataHashMap.put(SPECIES, HUMAN);
        DataHashMap.put(NATIONALITY, AMERICAN);
        DataHashMap.put(STATE, WASHINGTON);
        DataHashMap.put(GENDER, FEMALE);
        DataHashMap.put(OCCUPATION, BANKER);
        
        List<List<String>> lookup = new ArrayList<>();
        lookup.add(Arrays.asList(SPECIES, HUMAN, "H", "NH"));
        lookup.add(Arrays.asList(NATIONALITY, AMERICAN, "A", "NA"));
        lookup.add(Arrays.asList(STATE, WASHINGTON, "W", "NW"));
        lookup.add(Arrays.asList(GENDER, FEMALE, "F", "NF"));
        lookup.add(Arrays.asList(OCCUPATION, BANKER, "B", "NB"));



        List<String> EligibilityList = new ArrayList<>();
        
        for(List<String> item : lookup){
            if (item.get(1).equals(DataHashMap.get(item.get(0)))) {
                EligibilityList.add(item.get(2));
            } else {
                EligibilityList.add(item.get(3));
                break;
            }
        }

        System.out.println(EligibilityList);