@SpringBootApplication
public class SpringbootdemoApplication {
    public static void main(String[] args) {
        SpringApplication application = new SpringApplication(SpringbootdemoApplication.class);
        Map<String,Object> properties = new HashMap<>();
        properties.put("server.port",0);
        application.setDefaultProperties(properties);
        application.run(args);
//        new SpringApplicationBuilder(SpringbootdemoApplication.class)
//                .properties("server.port=0") //随机向OS要可用端口
//                .run(args);
}
 
 
 public static void main(String[] args) {
        SpringApplication application = new SpringApplication(SpringbootdemoApplication.class);
        Map<String,Object> properties = new HashMap<>();
        properties.put("server.port",0);
        application.setDefaultProperties(properties);
        application.setWebApplicationType(WebApplicationType.NONE);
        ConfigurableApplicationContext context = application.run(args);
        //class org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext
        //class org.springframework.context.annotation.AnnotationConfigApplicationContext(非web环境是这个)
        System.out.println(context.getClass());