你可以试着把一个方法设置为你的值的setter。这个方法然后把你的整数转换成字符串。

public static void main(String[] args) throws JsonProcessingException {
    ObjectMapper mapper = new ObjectMapper();

    String json = "{\"number\": 1}";
    Model model = mapper.readValue(json, Model.class);
    System.out.println(model.getNumber());
}

public class Model {
  private String number;

  public void setNumber(@JsonProperty("number") Integer number) {
    this.number = Integer.toString(number);
  }

  public String getNumber() {
    return number;
  }
}

我找到了新的约定，现在叫做JsonWriteFeature.WRITE_NUMBERS_AS_STRING)，而且.configure()需要放在JsonMapper.builder()之后。

ObjectMapper mapper = JsonMapper.builder()
                                    .configure(JsonWriteFeature.WRITE_NUMBERS_AS_STRINGS, true) 
                                    .build();