Jackson优雅序列化Java枚举类过程解析

/**
 * The interface Enumerator.
 */
public interface Enumerator {
  /**
   * Code integer.
   *
   * @return the integer
   */
  Integer code();

  /**
   * Description string.
   *
   * @return the string
   */
  String description();
}

public enum GenderEnum implements Enumerator {

  UNKNOWN(0, "未知"),

  MALE(1, "男"),

  FEMALE(2, "女");

  private final Integer code;
  private final String description;

  GenderEnum(Integer code, String description) {
    this.code = code;
    this.description = description;
  }

  @Override
  public Integer code() {
    return code;
  }

  @Override
  public String description() {
    return description;
  }
}

  @Resource
  private ObjectMapper objectMapper;

  @Test
  void enumTest() {
    try {
      String s = objectMapper.writeValueAsString(GenderEnum.MALE);
      // 输出字符串 MALE
      System.out.println(s);
    } catch (JsonProcessingException e) {
      e.printStackTrace();
    }
  }

     // 声明一个简单Module 对象
     SimpleModule module = new SimpleModule();
      // 给Module 添加一个序列化器
      module.addSerializer(Enumerator.class, new JsonSerializer<Enumerator>() {
        @Override
        public void serialize(Enumerator value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
          // 开始写入对象
          gen.writeStartObject();
          // 分别指定 k v  code  description
          gen.writeNumberField("code",value.code());
          gen.writeStringField("description",value.description());
          // 显式结束操作
          gen.writeEndObject();
        }
      });

    // 注册 Module
    objectMapper.registerModule(module);

@Bean
public Jackson2ObjectMapperBuilderCustomizer enumCustomizer(){
  return jacksonObjectMapperBuilder -> jacksonObjectMapperBuilder.serializerByType(Enumerator.class, new JsonSerializer<Enumerator>() {
    @Override
    public void serialize(Enumerator value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
          gen.writeStartObject();
          gen.writeNumberField("code",value.code());
          gen.writeStringField("description",value.description());
          gen.writeEndObject();

    }
  });
}