fastjson处理返回值为null的问题

    
        
            
                
                    
                    WriteMapNullValue
                    WriteNullNumberAsZero
                    WriteNullListAsEmpty
                    WriteNullStringAsEmpty
                    WriteNullBooleanAsFalse
                    WriteDateUseDateFormat
                
            
        
    

配置如上配置,字面意思是通过json返回类型自动将值设置成不为null的值.

springboot配置如下:

@Configuration
public class FastJsonMessage {

    @Bean
    public HttpMessageConverters fastJsonHttpMessageConverters() {
        //1、定义一个convert转换消息的对象
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        //2、添加fastjson的配置信息
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
       /* fastJsonConfig.setSerializerFeatures(
                SerializerFeature.WriteEnumUsingToString,
                SerializerFeature.WriteNullStringAsEmpty,
                SerializerFeature.WriteMapNullValue,
                SerializerFeature.WriteDateUseDateFormat);*/
        fastJsonConfig.setSerializeFilters((ValueFilter) (o, s, source) -> {
            if (source == null) {
                return "";            //此处是关键,如果返回对象的变量为null,则自动变成""
            }
            if (source instanceof Date) {
                return ((Date) source).getTime();
            }
            return source;
        });
        //2-1 处理中文乱码问题
        List fastMediaTypes = new ArrayList<>();
        fastMediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        fastConverter.setSupportedMediaTypes(fastMediaTypes);
        //3、在convert中添加配置信息
        fastConverter.setFastJsonConfig(fastJsonConfig);
        //4、将convert添加到converters中
        HttpMessageConverter converter = fastConverter;
        return new HttpMessageConverters(converter);
    }
}

QuoteFieldNames———-输出key时是否使用双引号,默认为true 
WriteMapNullValue——–是否输出值为null的字段,默认为false 
WriteNullNumberAsZero—-数值字段如果为null,输出为0,而非null 
WriteNullListAsEmpty—–List字段如果为null,输出为[],而非null 
WriteNullStringAsEmpty—字符类型字段如果为null,输出为”“,而非null 
WriteNullBooleanAsFalse–Boolean字段如果为null,输出为false,而非null