后端取的值：255864175623016448

前端得到值：255864175623016440

解决办法：

将Long类型转成String，再传给前端

方法一：

@JsonSerialize(using= ToStringSerializer.class)
private Long id;

方法二：

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.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;/*** 解决前后端交互Long类型精度丢失的问题*/
@Configuration
public class JacksonConfig {@Beanpublic ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {ObjectMapper objectMapper = builder.createXmlMapper(false).build();SimpleModule simpleModule = new SimpleModule();simpleModule.addSerializer(Long.class, ToStringSerializer.instance);objectMapper.registerModule(simpleModule);return objectMapper;}
}