springboot2.2.6.RELEASE chapter1

Spring Boot provides integration with three JSON mapping libraries:
• Gson
• Jackson
• JSON-B

Jackson是首选和默认库

使用 fastJson HttpMessageConverters

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.46</version>
        </dependency>

@Bean
    public HttpMessageConverters fastJsonHttpMessageConverters() {
        // 1.定义一个converters转换消息的对象
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        // 2.添加fastjson的配置信息，比如: 是否需要格式化返回的json数据
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(
                SerializerFeature.DisableCircularReferenceDetect,
                SerializerFeature.WriteMapNullValue,
                SerializerFeature.WriteDateUseDateFormat);
        // 3.在converter中添加配置信息
        fastConverter.setFastJsonConfig(fastJsonConfig);
        // 4.将converter赋值给HttpMessageConverter
        HttpMessageConverter<?> converter = fastConverter;
        // 5.返回HttpMessageConverters对象
        return new HttpMessageConverters(fastConverter);
    }