问题出现:
新项目将后端的Java Bean的id属性是用的Long类型对应数据库主键使用bigint类型,id改为雪花后出现的异常问题,比如id:1799633456368132098返回错误的id:1799633456368132000。导致明显问题数值精度丢失。后三位数值转换为0了。
问题原因:
Java中的long能表示的范围比js中number大,也就意味着部分数值在js中存不下(变成不准确的值),导致Id最后几位直接变成了0。
解决方案一
1、将后端id字段类型换位字符串类型,并且前端以字符串的方式接收就不会有精度丢失了。
2、单个字段注释,这只需要我们在需要转换的字段上增加@JsonSerialize(using=ToStringSerializer.class)注解
解决方案二
SpringBoot使用Jackson序列化方式
需要引入依赖
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jsr310</artifactId>
</dependency>
package com.znkj.nvm.common.config;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.TimeZone;
/**
* jackson 配置
* 加载顺序:-10000
**/
@Slf4j
@Order(-10000)
@Configuration
public class JacksonConfig {
@Bean
public Jackson2ObjectMapperBuilderCustomizer customizer() {
return builder -> {
// 全局配置序列化返回 JSON 处理
JavaTimeModule javaTimeModule = new JavaTimeModule();
javaTimeModule.addSerializer(Long.class, BigNumberSerializer.INSTANCE);
javaTimeModule.addSerializer(Long.TYPE, BigNumberSerializer.INSTANCE);
javaTimeModule.addSerializer(BigInteger.class, BigNumberSerializer.INSTANCE);
javaTimeModule.addSerializer(BigDecimal.class, ToStringSerializer.instance);
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(formatter));
javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(formatter));
builder.modules(javaTimeModule);
builder.timeZone(TimeZone.getDefault());
log.info("初始化 jackson 配置");
};
}
}
package com.gyq.common.config;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
import com.fasterxml.jackson.databind.ser.std.NumberSerializer;
import java.io.IOException;
/**
* 超出 JS 最大最小值 处理
**/
@JacksonStdImpl
public class BigNumberSerializer extends NumberSerializer {
/**
* 根据 JS Number.MAX_SAFE_INTEGER 与 Number.MIN_SAFE_INTEGER 得来
*/
private static final long MAX_SAFE_INTEGER = 9007199254740991L;
private static final long MIN_SAFE_INTEGER = -9007199254740991L;
/**
* 提供实例
*/
public static final BigNumberSerializer INSTANCE = new BigNumberSerializer(Number.class);
public BigNumberSerializer(Class<? extends Number> rawType) {
super(rawType);
}
@Override
public void serialize(Number value, JsonGenerator gen, SerializerProvider provider) throws IOException {
// 超出范围 序列化位字符串
if (value.longValue() > MIN_SAFE_INTEGER && value.longValue() < MAX_SAFE_INTEGER) {
super.serialize(value, gen, provider);
} else {
gen.writeString(value.toString());
}
}
}