问题描述：由于后端给前端响应的格式中不能处理Long类型，因为js只会处理前16位，这样会导致后面的精度丢失。

解决方法，将后端响应给前端的数据转化位JSON格式，将long类型的序列化一下

下面为具体方法(JAVA对象转化为JSON格式)，配置好即可

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import java.math.BigInteger;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import static com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES;/*** 对象映射器:基于jackson将Java对象转为json，或者将json转为Java对象* 将JSON解析为Java对象的过程称为 [从JSON反序列化Java对象]* 从Java对象生成JSON的过程称为 [序列化Java对象到JSON]*/
public class JacksonObjectMapper extends ObjectMapper {public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";public static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";public JacksonObjectMapper() {super();//收到未知属性时不报异常this.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);//反序列化时，属性不存在的兼容处理this.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);SimpleModule simpleModule = new SimpleModule().addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT))).addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT))).addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT))).addSerializer(BigInteger.class, ToStringSerializer.instance).addSerializer(Long.class, ToStringSerializer.instance).addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT))).addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT))).addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));//注册功能模块 例如，可以添加自定义序列化器和反序列化器this.registerModule(simpleModule);}
}[点击并拖拽以移动]
​

 将上述的工具类配置一下，并将其设置为mvc第一个消息转化器即可

import com.itheima.reggie.common.JacksonObjectMapper;
import lombok.extern.slf4j.Slf4j;
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.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;import java.util.List;@Configuration
@Slf4j
public class WebMvcConfig extends WebMvcConfigurationSupport {/*** 设置静态资源映射** @param registry*/@Overrideprotected void addResourceHandlers(ResourceHandlerRegistry registry) {log.info("开启资源映射");registry.addResourceHandler("/backend/**").addResourceLocations("classpath:/backend/");registry.addResourceHandler("/front/**").addResourceLocations("classpath:/front/");}/*** 扩展mvc框架的消息转换器** @param converters*/@Overrideprotected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {log.info("扩展消息转化器...");//创建消息转化器对象MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();//设置对象转化器，底层使用Jackson将Java对象转化为jsonmessageConverter.setObjectMapper(new JacksonObjectMapper());//将上面的消息转化器对象追加到mvc框架的转化器集合中converters.add(0,messageConverter);super.extendMessageConverters(converters);}
}