问题

比如后端返回Long.MAX_VALUE（9,223,372,036,854,775,807），前端得到的却是9,223,372,036,854,776,000；后4位精度损失

Screen Shot 2020-04-30 at 10.40.13 AM.png
Screen Shot 2020-04-30 at 10.40.25 AM.png

分析

• JavaScript中Number.MAX_SAFE_INTEGER为9007199254740991(正负2^53-1)
• Java 中Long的最大值为9,223,372,036,854,775,807（2^63 -1）
  所以JavaScript无法接受所有Long类型数据。

解决方案

如果Java后端中将要返回的值是Long类型，建议将Long转换成String类型

package com.mervyn.filterdemo;

import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
public class User {
    @JsonSerialize(using = ToStringSerializer.class)
    private Long id;
    private String name;

    public User(Long id, String name) {
        this.id = id;
        this.name = name;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

Screen Shot 2020-04-30 at 11.16.10 AM.png