将数组转换为 Java 中的 Json

Question

I have to convert an ArrayList of users to from java to JSON. I figured out how to get the user to convert, I don't know how to use the syntax for the array This is in the driver:

// Convert a User to JSON
String testStr = JsonUserConverter.convertUserToJson(bob);
System.out.println(testStr);

// Convert JSON string to a User
User testUser = JsonUserConverter.convertJsonToUser(jsonUserString);
System.out.println(testUser);

// Convert an ArrayList of Users to JSON

and I have to populate this

public static String convertUsersArrayToJson(ArrayList<User>users){}

with my User data from my User class. I only just learned about ObjectMapper. I assume there's something in my library to convert but I don't know. Help.

Answer 1

Here's a simple solution...

// Your User declarations (or however you have developed it)
User bob = new User();
User harry = new User();

// Declare an array
ArrayList<User> arrayListUsers = new ArrayList<User>();

// Construct the array by adding users
arrayListUsers.add(bob);
arrayListUsers.add(harry);
// and so on...

// Then call the convertUsersArrayToJson method
System.out.println( convertUsersArrayToJson(arrayListUsers) );


// And here’s the convertUsersArrayToJson() method
public static String convertUsersArrayToJson(List arrayListUsers){

    String jsonList = “”;

    for (User user : arrayListUsers) {

        jsonList += JsonUserConverter.convertUserToJson(user);

    }

    return jsonList;

}