解决前端精度丢失问题：后端Long类型到前端的处理

产生问题的原因：

关于这个问题是由于前端JavaScript的number类型的精度限制，如果说Long类型的值超过了number类型的精度范围，就会出现失去进度这样的问题，导致我们查询时数据id匹配不上。

解决方法：

方法一：使用@JsonSerialize注解将Long类型转换为String类型

@Data
public class QuestionSubmitVO implements Serializable {
    /**
     * id
     */
    @JsonSerialize(using = ToStringSerializer.class)
    private Long id;
}

方法二：使用@JsonFormat注解将Long类型格式化为String

public class QuestionSubmitVO implements Serializable {
    /**
     * id
     */
    @JsonFormat(shape = JsonFormat.Shape.STRING)
    private Long id;
}

方法三：全局配置Jackson将Long类型序列化为String

import com.fasterxml.jackson.databind.ObjectMapper;  
import com.fasterxml.jackson.databind.module.SimpleModule;  
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;  
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;  
import org.springframework.context.annotation.Bean;  
import org.springframework.context.annotation.Configuration;  
import org.springframework.context.annotation.Primary;  
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;  
  
@Configuration  
public class JacksonConfig {  
  
    @Bean  
    @Primary  
    @ConditionalOnMissingBean(ObjectMapper.class)  
    public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {  
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();  
        SimpleModule simpleModule = new SimpleModule();  
        // 将Long类型序列化为String类型  
        simpleModule.addSerializer(Long.class, ToStringSerializer.instance);  
        objectMapper.registerModule(simpleModule);  
        return objectMapper;  
    }  
}