[POJO to json String] #Java

Pojo2JsonStr.java

public String toString() throws Exception {
  ObjectMapper mapper = new ObjectMapper();
  mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
  String result;
  try {
    result = mapper.writeValueAsString(this);
  } catch (JsonProcessingException e) {
    throw new Exception("Cannot transfer backend server info to json string");
  }

  return result;
}