解决方法就是将Long型转换为字符串---全局配置方案如下：
@Override public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { // 初始化转换器 FastJsonHttpMessageConverter fastConvert = new FastJsonHttpMessageConverter(); // 初始化一个转换器配置 FastJsonConfig fastJsonConfig = new FastJsonConfig(); JSON.DEFFAULT_DATE_FORMAT = "yyyy-MM-dd HH:mm"; fastJsonConfig.setSerializerFeatures(SerializerFeature.BrowserCompatible,SerializerFeature.WriteNullListAsEmpty,SerializerFeature.PrettyFormat,SerializerFeature.WriteDateUseDateFormat,SerializerFeature.WriteNullStringAsEmpty,SerializerFeature.WriteMapNullValue,SerializerFeature.DisableCircularReferenceDetect); //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); // 将配置设置给转换器并添加到HttpMessageConverter转换器列表中 fastConvert.setFastJsonConfig(fastJsonConfig); converters.add(fastConvert); }