springboot处理long精度丢失的问题

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.ByteArrayHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.ResourceHttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.json.GsonHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
import org.springframework.web.servlet.config.annotation.*;

import java.nio.charset.Charset;
import java.util.List;

/**
 * @Classname WebConfig
 * @Description TODO
 * @Date 2021/8/11 9:06 下午
 * @Created by zk
 */
@EnableWebMvc
@Configuration
public class WebMVCConfig extends WebMvcConfigurerAdapter {
    /*@Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        MappingJackson2HttpMessageConverter jackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
        ObjectMapper objectMapper = new ObjectMapper();
        *//**
         * 序列换成json时,将所有的long变成string
         * 因为js中得数字类型不能包含所有的java long值
         *//*
        SimpleModule simpleModule = new SimpleModule();
        simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
        simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);
        objectMapper.registerModule(simpleModule);
        jackson2HttpMessageConverter.setObjectMapper(objectMapper);
        converters.add(jackson2HttpMessageConverter);
    }*/

    @Autowired
    public GsonHttpMessageConverter gsonHttpMessageConverter;


    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters){
        StringHttpMessageConverter stringConverter = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        stringConverter.setWriteAcceptCharset(false);
        converters.add(new ByteArrayHttpMessageConverter());
        converters.add(stringConverter);
        converters.add(new ResourceHttpMessageConverter(source));
//        MappingJackson2HttpMessageConverter jackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
//        jackson2HttpMessageConverter.setObjectMapper();

　　　　　converters.add(new AllEncompassingFormHttpMessageConverter());
　　　　　converters.add(gsonHttpMessageConverter);

        converters.add(new Jaxb2RootElementHttpMessageConverter());//xml转换
    }

    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer){
        configurer.favorParameter(false).favorParameter(false);

    }
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**").addResourceLocations(
                "classpath:/static/");
        registry.addResourceHandler("swagger-ui.html").addResourceLocations(
                "classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations(
                "classpath:/META-INF/resources/webjars/");
        super.addResourceHandlers(registry);
    }
}

方法二
long数据能表示的范围比js中number大,在跟前端交互时，这样也就意味着部分数值在js中存不下(变成不准确的值)

@JsonSerialize(using = ToStringSerializer.class)
将date转化为秒

public class DateToLongSerializer extends JsonSerializer<Date> {
@Override
public void serialize(Date date, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
jsonGenerator.writeNumber(date.getTime() / 1000);
}
可以使用

com.fasterxml.jackson.core-jackson-databind包里边

com.fasterxml.jackson.databind.ser.std下类