解决Java Long类型转为Json后，Js调用精度丢失问题

最新推荐文章于 2024-08-09 19:36:20 发布

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最新推荐文章于 2024-08-09 19:36:20 发布

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分类专栏： # Spring 疑难杂问文章标签： springboot、springmvc WebMvcConfigurer WebMvcConfigurerAdapter Long转Json精度缺失 @JsonSerialize

本文链接：https://blog.csdn.net/minkeyto/article/details/102984455

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一、局部转换

1、添加注解到实体类属性上，将Long类型的数据转换成json时转化成String类型

方式一：

@JsonFormat(shape=JsonFormat.Shape.STRING)

需要导包：

import com.fasterxml.jackson.annotation.JsonFormat;

方式二：推荐

@JsonSerialize(using = ToStringSerializer.class)

需要导包：

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;

二、配置全局转换器

方式一：SpringBoot架构

1、实现 WebMvcConfigurer 接口

2、重写 configureMessageConverters 方法

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
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.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.List;

@EnableWebMvc
@Configuration
public class WebLongToStringConfig implements WebMvcConfigurer {

    @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);
    }

}

方式二：SpringBoot架构

1、继承 WebMvcConfigurerAdapter 类

2、重写 configureMessageConverters 方法

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
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.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
import java.util.List;
 
@EnableWebMvc
@Configuration
public class WebLongToStringConfig extends WebMvcConfigurerAdapter {
        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);
        }
}

方式三：SpringMVC架构

1、继承 ObjectMapper 类

2、添加LongJsonMapper 类为自定义转换器，重写registerModule方法

public class LongJsonMapper extends ObjectMapper {
 
    @Override
    public ObjectMapper registerModule(Module module) {
       /**
        * 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);
        return super.registerModule(simpleModule);
    }
}

3、配置到springmvc文件中即可

<bean id="mappingJackson2HttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>application/json</value>
                <value>application/xml</value>
                <value>text/html</value>
                <value>text/plain</value>
                <value>text/xml</value>
            </list>
        </property>
        <property name="objectMapper" ref="longJsonMapper"/>
</bean>

<bean id="longJsonMapper" class="此处配置为LongJsonMapper的类路径"/>