如何对地图进行排序 <String, List<class> &gt;

Question

我有这张地图，其中包含姓名，姓氏和其他个人信息，例如：

jhon:[doe];

ann:[devil]

我想要按字母顺序对它们进行排序，但是这种结构对我来说是新的。 如何按字母顺序排序？ 这是我的代码

 private String uid;
    private String username;
    private String fullName;
    private String name;
    private String lastname;
    private String email;
    private String phone;
    private Map<String, List<PorticoProfile>> profiles;

    public Map<String, List<PorticoProfile>> getProfiles() {
        if (profiles == null) {
            profiles = new LinkedHashMap<>();
        }
        return profiles;
    }

    public void setProfiles(Map<String, List<PorticoProfile>> profiles) {
        this.profiles = profiles;
    }

    public void setFullName(String fullName) {
        this.fullName = fullName;
        if (fullName.contains(" ")){
            String[] nameParts = fullName.split(" ");
            this.name = nameParts[0];
            this.lastname = nameParts[1];
        }
    }

    @Override
    public String toString(){
        final String BREAK = System.getProperty("line.separator");
        StringBuilder sb = new StringBuilder();
        sb.append("uid: ").append(this.uid).append(BREAK);
        sb.append("username: ").append(this.username).append(BREAK);
        sb.append("fullname: ").append(this.fullName).append(BREAK);
        sb.append("email: ").append(this.email).append(BREAK);
        sb.append("phone: ").append(this.phone).append(BREAK);
        if (this.getProfiles().size() > 0){
            sb.append("profiles: ").append(this.profiles.keySet().stream().collect(Collectors.joining(", "))).append(BREAK);
        }
        return sb.toString();
    }

Answer 1

我认为您应该签出另一个接口：SortedMap（ https://docs.oracle.com/javase/8/docs/api/java/util/SortedMap.html ）

    Map<String, Object> m = new HashMap<>();
    m.put("john", "doe");
    m.put("ann", "devil");

    SortedMap<String, Object> s = new TreeMap<>(m);
    s.entrySet().forEach(System.out::println);

Answer 2

使用TreeMap - https: TreeMap

LinkedHashMap将保留将数据添加到Map的顺序， TreeMap将根据密钥对数据进行排序，在您的情况下为String即名称

Map<String, List<PorticoProfile>> profiles = new TreeMap<>();;

Answer 3

尝试：

Map<String, List<MyClass>> sorted = map.entrySet()
        .stream()
        .sorted(Comparator.comparing(Map.Entry::getKey)) // sort by key
        .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));