关于JAVA的LONG 类型到JS丢失精度的问题
写代码碰到一个bug, 现象是 后台Java返回的18位的Long类型的数据,到前台丢失了精度还有前端在数据编辑的时候出现问题
(如上图所示前端请求对象两个数字其实都是对应同一个产品的id,上面字符串没问题,下面前端同事传的数字), 查了一下,原因是
java的Long类型是18位, 而 js的Long类型(虽然没有明确定义的Long类型)是16位, 所以会造成丢失精度,
解决办法:
1:将后台的Long转换为字符串传回前台(其中一种较简单的方案就是在字段上面标注注解:@JsonSerialize(using = ToStringSerializer.class)),
前端提交的时候也提交字符串(如果转为数字就会失真,后台字符串会自动转化为long)
2:Spring Boot项目可以配置一个全局处理器,将long转行为String
import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.annotation.JsonInclude; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.module.SimpleModule; import com.fasterxml.jackson.databind.ser.std.ToStringSerializer; import org.springframework.context.annotation.Configuration; import org.springframework.http.converter.HttpMessageConverter; import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter; import org.springframework.web.servlet.config.annotation.EnableWebMvc; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; import java.util.List; @EnableWebMvc @Configuration public class WebJsonConverterConfig implements WebMvcConfigurer { public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { MappingJackson2HttpMessageConverter jackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter(); ObjectMapper objectMapper = new ObjectMapper(); objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); SimpleModule simpleModule = new SimpleModule(); simpleModule.addSerializer(Long.class, ToStringSerializer.instance); simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance); //null属性不序列化 objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL); objectMapper.registerModule(simpleModule); jackson2HttpMessageConverter.setObjectMapper(objectMapper); converters.add(jackson2HttpMessageConverter); } }