SpringBoot实体Long传递到前端丢失精度

Edited on In ,

问题

主键 Long 型返回到前端丢失精度问题

两种简单的解决方式：

  1. @JSONField(serializeUsing = ToStringSerializer.class)

2.@JsonSerialize(using = LongToStringSerializer.class)

fastjson中的ToStringSerializer
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public class ToStringSerializer implements ObjectSerializer {

    public static final ToStringSerializer instance = new ToStringSerializer();

    @Override
    public void write(JSONSerializer serializer, Object object, Object fieldName, Type fieldType,
                      int features) throws IOException {
        SerializeWriter out = serializer.out;
        if (object == null) {
            out.writeNull();
            return;
        }
        String strVal = object.toString();
        out.writeString(strVal);
    }
}
自定义类 LongToStringSerializer
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public class LongToStringSerializer extends JsonSerializer<Long> {
    @Override
    public void serialize(Long value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        if (value == null) {
            gen.writeNull();
            return;
        }
        gen.writeString(value.toString());
    }
}

一劳永逸的解决方式(序列化、反序列化)

此解决方案是 springboot 中使用jackson

在 WebMvcConfigurer中，配置 objectMapper 的 bean
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/**
 * WebMvcConfigurer
 *
 * @author maxzhao
 * @date 2020-03-05 14:23
 */
@Component
public class BootWebMvcConfigurer implements WebMvcConfigurer {
    /**
     * Json序列化和反序列化转换器，用于转换Post请求体中的json以及将我们的对象序列化为返回响应的json
     */
    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);

        /*LocalDateTime系列序列化和反序列化模块，继承自jsr310，我们在这里修改了日期格式
         * 在这里修改之后，就不用再去全局序列化了*/
        JavaTimeModule javaTimeModule = new JavaTimeModule();
        javaTimeModule.addSerializer(LocalDateTime.class
                , new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DateBootUtil.DEFAULT_DATETIME_FORMAT)));
        javaTimeModule.addSerializer(LocalDate.class
                , new LocalDateSerializer(DateTimeFormatter.ofPattern(DateBootUtil.DEFAULT_DATE_FORMAT)));
        javaTimeModule.addSerializer(LocalTime.class
                , new LocalTimeSerializer(DateTimeFormatter.ofPattern(DateBootUtil.DEFAULT_TIME_FORMAT)));
        javaTimeModule.addDeserializer(LocalDateTime.class
                , new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DateBootUtil.DEFAULT_DATETIME_FORMAT)));
        javaTimeModule.addDeserializer(LocalDate.class
                , new LocalDateDeserializer(DateTimeFormatter.ofPattern(DateBootUtil.DEFAULT_DATE_FORMAT)));
        javaTimeModule.addDeserializer(LocalTime.class
                , new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DateBootUtil.DEFAULT_TIME_FORMAT)));
        javaTimeModule.addSerializer(Long.class
                , new LongToStringSerializer());
        /*Date序列化和反序列化  jackson-datatype-jsr310 包中已经存在 这里就不用再次写了*/
        objectMapper.registerModule(javaTimeModule);
        return objectMapper;
    }
}

本文地址： https://github.com/maxzhao-it/blog/post/45ed5038/