springboot学习之——SpringApplication.run方法

目录

• springboot学习之——SpringApplication.run方法
  • 第一步
  • 第二步
    • ConfigurableApplicationContext

springboot 版本3.1.5

第一步

   /
     * Static helper that can be used to run a {@link SpringApplication} from the
     * specified source using default settings.
     * @param primarySource the primary source to load
     * @param args the application arguments (usually passed from a Java main method)
     * @return the running {@link ApplicationContext}
     */
    public static ConfigurableApplicationContext run(Class<?> primarySource, String... args) {
        return run(new Class<?>[] { primarySource }, args);
    }

   /
     * Create a new {@link SpringApplication} instance. The application context will load
     * beans from the specified primary sources (see {@link SpringApplication class-level}
     * documentation for details). The instance can be customized before calling
     * {@link #run(String...)}.
     * @param resourceLoader the resource loader to use
     * @param primarySources the primary bean sources
     * @see #run(Class, String[])
     * @see #setSources(Set)
     /
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
        this.resourceLoader = resourceLoader;//null
        Assert.notNull(primarySources, "PrimarySources must not be null");
        this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));//这个资源类就是自己
        this.webApplicationType = WebApplicationType.deduceFromClasspath();//推断使用什么类型的web应用。我们经常用WEBMVC_INDICATOR_CLASS
        this.bootstrapRegistryInitializers = new ArrayList<>(
                getSpringFactoriesInstances(BootstrapRegistryInitializer.class));//启动注册实例化
        setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));
        setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));//监听器
        this.mainApplicationClass = deduceMainApplicationClass();//主应用类（就是自己项目的启动类）
    }

/
 * SPI interface to be implemented by most if not all application contexts.
 * Provides facilities to configure an application context in addition
 * to the application context client methods in the
 * {@link org.springframework.context.ApplicationContext} interface.
 
 * <p>Configuration and lifecycle methods are encapsulated here to avoid
 * making them obvious to ApplicationContext client code. The present
 * methods should only be used by startup and shutdown code.
 
 * @author Juergen Hoeller
 * @author Chris Beams
 * @author Sam Brannen
 * @since 03.11.2003
 */
public interface ConfigurableApplicationContext extends ApplicationContext, Lifecycle, Closeable {
}

   /
     * Create a new {@link AnnotationConfigServletWebApplicationContext}, deriving bean
     * definitions from the given annotated classes and automatically refreshing the
     * context.
     * @param annotatedClasses one or more annotated classes, e.g. {@code @Configuration}
     * classes
     /
    public AnnotationConfigServletWebApplicationContext(Class<?>... annotatedClasses //注册被注解的类) {
        this();
        register(annotatedClasses);
        refresh();
    }