springboot 使用fastjson替代默認jackson（踩坑路）

最安全做法使用bean替代默認轉換器方法

@Configuration
public class MyConfiguration {

    @Bean
    public HttpMessageConverters customConverters() {
        List<HttpMessageConverters> converters = new ArrayList<>();
        // 1、需要先定義一個convert轉換消息的對象；
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        // 2、添加fastjson的配置信息，比如 是否要格式化返回json數據
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);
        // 3、在convert中添加配置信息.
        fastConverter.setFastJsonConfig(fastJsonConfig);
        // 4、將convert添加到converters當中.
        converters.add(fastConverter);
        return new HttpMessageConverters(true, converters);
    }

}

第二種做法

實現WebMvcConfigurer，需要將jackson依賴移除才能生效（缺點不能加入jackson，gson等，否則spring會自動裝配）

@Configuration
public class SpringMvcConfigure implements WebMvcConfiguration{

    /**
     * 配置消息轉換器
     * @param converters
     */
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();
        //自定義配置...
        FastJsonConfig config = new FastJsonConfig();
        config.setSerializerFeatures(SerializerFeature.QuoteFieldNames,
                SerializerFeature.WriteEnumUsingToString,
                /*SerializerFeature.WriteMapNullValue,*/
                SerializerFeature.WriteDateUseDateFormat,
                SerializerFeature.DisableCircularReferenceDetect);
        fastJsonHttpMessageConverter.setFastJsonConfig(config);
        converters.add(fastJsonHttpMessageConverter);
    }

}

第三種實現父類,缺點很明顯，完全接管的springmvc，默認配置全部失效，需要重新自己配置

@Configuration
public class SpringMvcConfigure extends WebMvcConfigurationSupport{

    /**
     * 配置消息轉換器
     * @param converters
     */
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();
        //自定義配置...
        FastJsonConfig config = new FastJsonConfig();
        config.setSerializerFeatures(SerializerFeature.QuoteFieldNames,
                SerializerFeature.WriteEnumUsingToString,
                /*SerializerFeature.WriteMapNullValue,*/
                SerializerFeature.WriteDateUseDateFormat,
                SerializerFeature.DisableCircularReferenceDetect);
        fastJsonHttpMessageConverter.setFastJsonConfig(config);
        converters.add(fastJsonHttpMessageConverter);
        supper.configureMessageConverters(converters);
    }

}