springboot中配置addResourceHandler和addResourceLocations，使得能够从磁盘中读取图片、视频、音频等

项目相对目录:classpath:

本地绝对目录:file:

@Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**").addResourceLocations("classpath:/static/");
        registry.addResourceHandler("swagger-ui.html")
                .addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/");
        //其中OTA表示访问的前缀。"file:D:/OTA/"是文件真实的存储路径
        registry.addResourceHandler("/upload/img/**").addResourceLocations("file:G:\\upload\\");
        super.addResourceHandlers(registry);
    }