# 如何处理Long类型精度丢失问题? >[info] 当实体类中的字段为`Long`类型，且值超过前端`js`显示的长度范围时会导致前端回显错误。 ### 方法1 使用@JsonSerialize注解的时候把Long自动转为String ``` @JsonSerialize(using = ToStringSerializer.class) private Long id; ``` ### 方法2 使用@JsonFormat注解的时候把Long自动转为String ``` @JsonFormat(shape = JsonFormat.Shape.STRING) private Long id; ``` ### 方法3 全局配置org.jeecg.config.WebMvcConfiguration中添加如下代码 ``` builder.serializerByType(Long.class, ToStringSerializer.instance); builder.serializerByType(Long.TYPE, ToStringSerializer.instance); ``` 具体配置如下 ``` @Bean public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() { return builder -> { DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"); //返回时间数据序列化 builder.serializerByType(LocalDateTime.class, new LocalDateTimeSerializer(formatter)); //接收时间数据反序列化 builder.deserializerByType(LocalDateTime.class, new LocalDateTimeDeserializer(formatter)); //序列化Long builder.serializerByType(Long.class, ToStringSerializer.instance); builder.serializerByType(Long.TYPE, ToStringSerializer.instance); }; } ```