Long类型损失精度

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    /**
     * 利用fastJson替换掉jackson，且解决中文乱码问题
     */

    @Bean
    public HttpMessageConverters fastJsonHttpMessageConverters() {
        //1.需要定义一个convert转换消息的对象;
        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter() {
            @Override
            protected boolean supports(Class<?> clazz) {
                return clazz != String.class && super.supports(clazz);
            }
        };
        //2:添加fastJson的配置信息;
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(
                SerializerFeature.DisableCircularReferenceDetect,
                SerializerFeature.WriteMapNullValue,
                SerializerFeature.WriteNullNumberAsZero,
                SerializerFeature.WriteNullStringAsEmpty,
                SerializerFeature.WriteNullListAsEmpty,
                SerializerFeature.WriteNullBooleanAsFalse,
                SerializerFeature.WriteNonStringKeyAsString,
                SerializerFeature.WriteNonStringValueAsString,
                SerializerFeature.BrowserCompatible);
        //解决Long转json精度丢失的问题
        SerializeConfig serializeConfig = SerializeConfig.globalInstance;
        serializeConfig.put(BigInteger.class, ToStringSerializer.instance);
        serializeConfig.put(Long.class, ToStringSerializer.instance);
        serializeConfig.put(Long.TYPE, ToStringSerializer.instance);
        fastJsonConfig.setSerializeConfig(serializeConfig);
        //3处理中文乱码问题
        List<MediaType> fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        //4.在convert中添加配置信息.
        fastJsonHttpMessageConverter.setSupportedMediaTypes(fastMediaTypes);
        fastJsonHttpMessageConverter.setFastJsonConfig(fastJsonConfig);
        HttpMessageConverter<?> converter = fastJsonHttpMessageConverter;
        return new HttpMessageConverters(converter);
    }
}

在applicationContext.xml配置文件中修改fastjson为默认的解析器

<mvc:annotation-driven>
    <mvc:message-converters register-defaults="true">
        <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
            <property name="supportedMediaTypes">
                <list>
                    <value>text/html;charset=UTF-8</value>
                    <value>application/json</value>
                    <value>application/xml;charset=UTF-8</value>
                </list>
            </property>
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>

输出null为空字符串””,使用自定义过滤器

private static ValueFilter filter = new ValueFilter() {
    @Override
    public Object process(Object obj, String s, Object v) {
        if (v == null)
            return "";
        return v;
    }
};

public String toJson() {
    return JSON.toJSONString(this, filter,
            SerializerFeature.DisableCircularReferenceDetect,
            SerializerFeature.WriteMapNullValue,
            SerializerFeature.WriteNullNumberAsZero,
            SerializerFeature.WriteNullStringAsEmpty,
            SerializerFeature.WriteNullListAsEmpty,
            SerializerFeature.WriteNullBooleanAsFalse,
            SerializerFeature.WriteNonStringKeyAsString,
            SerializerFeature.WriteNonStringValueAsString,
            SerializerFeature.BrowserCompatible
    );
}