public class User {
private String name;
private int age;
private String address;
// getters and setters
}
ObjectMapper objectMapper = new ObjectMapper();
User user = new User();
user.setAge(25);
ObjectNode userNode = objectMapper.valueToTree(user);
ObjectNode filteredUserNode = objectMapper.createObjectNode();
filteredUserNode.put("name", userNode.get("name"));
filteredUserNode.put("age", userNode.get("age"));
String json = objectMapper.writeValueAsString(filteredUserNode);
