@Configuration

public class CustMvcConfig extends WebMvcConfigurationSupport {

    @Autowired

    private FastJsonHttpMessageConverter fastJsonConverter;

    @Override

    protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {

        super.configureMessageConverters(converters);

        converters.add(new ByteArrayHttpMessageConverter()); // ByteArrayHttpMessageConverter 必须加在前面，处理byte数据

        converters.add(fastJsonConverter);// fastjsonConverter 必须加在后面 处理json数据

    }

}