Spring Boot

• Application.java启动类
  • 用@SpringBootApplication标识Application.java启动类
    • @SpringBootApplication相当于@Configuration + @EnableAutoConfiguration + @ComponentScan
      • @Configuration: Tags the class as a source of bean definitions for the application context.
      • @EnableAutoConfiguration: Tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings. For example, if spring-webmvc is on the classpath, this annotation flags the application as a web application and activates key behaviors, such as setting up a DispatcherServlet.
      • @ComponentScan: Tells Spring to look for other components, configurations, and services in the hello package, letting it find the controllers.
    • 可以通过scanBasePackages指定要扫描的包，相当于@ComponentScan，如@SpringBootApplication(scanBasePackages = {"com.yyy", "com.xxx" })
  • 其实最终使用了Spring Boot提供的启动方法：SpringApplication.run(Application.class, args);
• 打包运行
  • 可以使用Gradle、Maven来运行、打包程序
  • 默认打包成可执行的jar包，并包含一个内嵌的servlet容器 - Tomcat作为Http runtime。
  • jar包中的Main函数就是前面用@SpringBootApplication标识的Application.java启动类
  • 运行jar包：java -jar xxx.jar
• 启动并指定用哪个profile
  • 从Spring Boot项目根目录启动时指定：java org.springframework.boot.loader.JarLauncher —spring.profiles.active=xxx
  • 启动jar包时指定：java -Dspring.profiles.active=xxx -jar yyy.jar