Question

我有一个名为usersJ的类，其中有一个类型列表的单个字段。我想将类中的信息插入到json文件中。我不知道代码中缺少什么，但由于某种原因我无法写入文件，它仍然是空的。我尝试使用以下函数执行此操作（我还包括UsersJ和用户代码） -

public class UsersJ {
    private List<User> users;

    public UsersJ ( ConcurrentHashMap<String , User> allUser){
        users = new ArrayList<>(allUser.values());
    }
}

用户类 -

public class User {
    private String username;
    private String password;
    private String country;
    private LinkedList<MoviePairInfo> movies;
    private int balance;
    private final String type;


public User( String _username,String _password , String _country){
    username = _username;
    password = _password;
    country = _country;
    balance = 0;
    type = "";
    movies = new LinkedList<>();
}
}

和功能 -

 public void write_to_user( ConcurrentHashMap<String , User> allUser){
       UsersJ users = new UsersJ(allUser);
       Gson gson = new GsonBuilder().create();
       String path = "Users.json";
       try{
           FileWriter a = new FileWriter(path);
           gson.toJson(users , UsersJ.class , a);
       } catch (FileNotFoundException e){
           e.printStackTrace();
       } catch (IOException e){
           e.printStackTrace();
       }
    }

有没有人有想法？

如何将类插入json文件

0 个答案: