如何将临时类转换为json？

import com.fasterxml.jackson.databind.ObjectMapper;

public class TempClass {
    private String name;
    private int age;

    // Getter and setter methods

    public static void main(String[] args) {
        TempClass temp = new TempClass();
        temp.setName("John");
        temp.setAge(25);

        ObjectMapper objectMapper = new ObjectMapper();
        try {
            String json = objectMapper.writeValueAsString(temp);
            System.out.println(json);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}